Graduation 1992; DMD (Dr. med. dent.) 1993; PhD (Priv.-Doz.) 2000; Associate Professor (apl. Prof.) 2006; Professor and Chairman, Department of Operative Dentistry and Endodontology, University of Marburg 2009, Editor-in-Chief, Quintessence Germany 2011, President of the German Association of Conservative Dentistry 2012, Dean of Dental School 2012.
Abstract: The purposes of this study were to investigate the effects of thermal residual stresses on the reliability and lifetime of zirconia-veneer crowns.
Abstract: The objective of this study was to evaluate the marginal quality and resin-resin transition of milled CAD/CAM glass-ceramic inlays in deep proximal cavities with and without 3-mm proximal box elevation (PBE) using resin composites before and after thermomechanical loading.
Abstract: A new approach to fill tunnel preparations with composites of two different consistencies is presented. Removal of caries through a narrow access space and reliably filling this cavity are the two main problems with tunnel-prepared teeth. Caries removal can be supplemented by the use of hand instruments, especially curettes, but filling the lesion with composite of a single consistency is problematic. Flowable composite alone does not create enough pressure to place the filling material into shallow extensions of the lesion; packable composite does not flow well enough. A solution for this problem may be a dual-consistency technique: flowable composite is placed, followed by packable composite, with no light curing in between. The flowable composite is pressed into small details of the cavity by the pressure created by the packable composite.
Abstract: Aim of the present prospective controlled clinical study was to compare the clinical performances of two different cementation procedures to lute IPS Empress inlays and onlays.
Abstract: The load capability of post-restored endodontically treated teeth (ETT) can be determined at different restorative stages. It was the aim of this study to compare the load capability of ETT at these stages.
Abstract: To evaluate fatigue behavior of direct resin composite restorations (Tetric Ceram vs. Grandio) in vitro and in vivo over an observation period of 6 years.
Abstract: When the International Caries Detection and Assessment System (ICDAS-II) was introduced, a two-number coding system that identifies restorations/sealants with the first digit and scores the caries lesions with a second digit was suggested. The aim of this study was, first, to assess the intra- and interexaminer reproducibility of this method applied by predoctoral dental students and, second, to evaluate the influence of an additional theoretical training session on the reproducibility values. Twenty-four third-year dental students at Philipps University of Marburg, Germany, were trained in a theoretical session by an experienced examiner. The students were randomly divided into two groups to examine extracted teeth. The assessments were repeated after three weeks. Prior to the second examinations, one group received an additional theoretical training session. For the restoration code, mean kappa values for intra- and interexaminer reproducibility were between 0.28 and 0.82. For the caries code, mean kappa values for intra- and interexaminer reproducibility were between 0.34 and 0.72. The mean kappa values of the two groups did not differ significantly, either on the first digit or on the caries code (p>0.05).
Abstract: Adhesively luted all-ceramic restorations represent a promising way to preserve and stabilize weakened tooth substance, but little information is published about the clinical performance of extensive all-ceramic restorations.
Abstract: To evaluate marginal quality and resin-resin transition of lab made resin composite inlays in deep proximal cavities with and without 3 mm proximal box elevation (PBE) using resin composites before and after thermo-mechanical loading (TML).
Abstract: Odontomas account for the largest fraction of odontogenic tumors and are frequent causes of tooth impaction. A case of a 13-year-old female patient with an odontoma-associated impaction of a mandibular molar is presented with a review of the literature. Preoperative planning involved simple and convenient methods such as clinical examination and panoramic radiography, which led to a diagnosis of complex odontoma and warranted surgical removal. The clinical diagnosis was confirmed histologically. Multidisciplinary consultation may enable the clinician to find the accurate diagnosis and appropriate therapy based on the clinical and radiographic appearance. Modern radiologic methods such as cone-beam computed tomography or computed tomography should be applied only for special cases, to decrease radiation.
Abstract: We evaluated the effects of preliminary etching of dentine on the stability of the bond created by one-step self-etch adhesives under different storage conditions. Adper Easy Bond (3M ESPE) and iBond Self-Etch (iBond SE; Heraeus Kulzer) were applied with an etch-and-rinse (i.e. after preliminary phosphoric acid etching for 15 s) or a self-etch approach. Resin-dentine bonded specimens were sectioned perpendicularly to the adhesive interface according to the 'non-trimming technique'. Beams were stored in artificial saliva for 24 h, 6 months, or 1 yr at 37°C, or in 10% NaOCl for 5 h at room temperature, and then stressed until failure; the microtensile bond strengths were calculated. Interfacial nanoleakage of additional teeth was evaluated using light microscopy or transmission electron microscopy. Adper Easy Bond showed higher bond strength than iBond SE, regardless of the dentine treatment. Similar microtensile bond strength results were obtained for teeth subjected to artificial ageing in 10% NaOCl for 5 h at room temperature and for teeth stored in artificial saliva for 6 months at 37°C. The additional etching step increased the microtensile bond strength for Adper Easy Bond and iBond SE. This study supports the use of one-step adhesives on etched dentine because of the increased bond strength compared with their application onto smear-layer-covered dentine, regardless of storage conditions.
Abstract: This ex vivo pilot study tested the influence of defect extension and quartz-fiber post placement (QFP) on the ex vivo survival rate and fracture resistance of root-treated upper central incisors served as abutments for zirconia 2-unit cantilever fixed partial dentures (2U-FPDs) exposed to 10 years of simulated clinical function.
Abstract: OBJECTIVES: The aim was to study the impact of the defect size of endodontically treated incisors compared to dental implants as abutments on the survival of zirconia two-unit anterior cantilever-fixed partial dentures (2U-FPDs) during 10-year simulation. MATERIALS AND METHODS: Human maxillary central incisors were endodontically treated and divided into three groups (n = 24): I, access cavities rebuilt with composite core; II, teeth decoronated and restored with composite; and III as II supported by fiber posts. In group IV, implants with individual zirconia abutments were used. Specimens were restored with zirconia 2U-FPDs and exposed to two sequences of thermal cycling and mechanical loading. Statistics: Kaplan-Meier; log-rank tests. RESULTS: During TCML in group I two tooth fractures and two debondings with chipping were found. Solely chippings occurred in groups II (2×), IV (2×), and III (1×). No significant different survival was found for the different abutments (p = 0.085) or FPDs (p = 0.526). Load capability differed significantly between groups I (176 N) and III (670 N), and III and IV (324 N) (p < 0.024). CONCLUSION: Within the limitations of an in vitro study, it can be concluded that zirconia-framework 2U-FPDs on decoronated teeth with/without post showed comparable in vitro reliability as restorations on implants. The results indicated that restorations on teeth with only access cavity perform worse in survival and linear loading. CLINICAL RELEVANCE: Even severe defects do not justify per se a replacement of this particular tooth by a dental implant from load capability point of view.
Abstract: To assess the influence of different temporary restorations and luting techniques of labside and chairside ceramic inlays on enamel defects and marginal integrity.
Abstract: This study evaluated marginal integrity of bonded posterior resin composite fillings to enamel and dentine with and without 4mm flowable base, before and after thermo-mechanical loading (TML).
Abstract: In a controlled prospective split-mouth study, clinical behavior of two different resin composites in extended Class II cavities was observed over six years.
Abstract: Simulation of tooth mobility in vitro with or without reduced bone support is an aspect of particular interest from the clinical perspective. To elucidate adequate simulation of the periodontal ligament in terms of tooth mobility, three materials were investigated.
Abstract: To investigate the load capability of root filled teeth restored with glass fibre posts when the same self-adhesive composite resin cement was used as post cement and core build-up material.
Abstract: A novel approach to the pull-out test using silica-coated and silanized steel spreaders was designed to avoid influence from the post-cement interface. In this study, this test was applied to compare the post retention of adhesive versus conventional cements.
Abstract: Although an interaction of malocclusion, parafunction, and temporomandibular joint disorders (TMD) can be inferred from the experience of daily practice, scientific evidence to corroborate this hypothesis does not exist. However, there are indications that TMD and headaches may be intertwined.
Abstract: To evaluate marginal integrity of direct resin composite restorations before and after thermo-mechanical loading in vitro, and before and after 6 years of clinical service in a prospective clinical trial.
Abstract: The null hypothesis was tested: There is no difference between two all-ceramic crown systems, the Cerec method (CHAIR) and the IPS Empress method (LAB), with respect to occlusal precision and time expenditure for the dentist.
Abstract: The aim of this investigation was to test the in vitro performance of a self-adhesive resin composite core build-up in comparison with two typical conventional etch-and-rinse composite core build-up materials, before and after 1year of storage in 0.5% chloramine solution (LTS). Sixty human maxillary central incisors were divided into three groups. Teeth were root filled and decoronated. Specimens were restored using glass fiber posts cemented with a self-adhesive resin cement. Core build-ups were made with a self-adhesive (U) and two core build-up materials (C and L) applied with their corresponding bonding systems. All specimens received adhesively luted lithium disilicate crowns. Ten specimens of each group were exposed to LTS and examined monthly for cracks or other alterations. All specimens were thermocycled, mechanically loaded (TCML) and finally loaded until failure occurred. There was no statistical significant difference in regard to the number of failures during TCML without and with LTS (log rank: p = 0.225 and 0.609, respectively). The median fracture load values after static loading without LTS and with LTS did not differ significantly (Kruskal-Wallis test: p = 0.057 and 0.106, respectively), though the fracture patterns between the groups without (p = 0.024) and with LTS (p = 0.027) did. Self-adhesive cements used for core build-up have no significantly higher risk of failure compared to conventional core build-up materials in both LTS and TCML test scenarios.
Abstract: The aim of this study was to analyse the effect of preliminary phosphoric acid etching of enamel and dentine before the application of two, one-step self-etch adhesive systems. The systems were applied onto acid-etched or smear-layer-covered enamel and dentine. The treatment groups were as follows: group 1, Adper Easy Bond (3M ESPE) on etched substrate; group 2, Adper Easy Bond (control); group 3, iBond Self-Etch (Heraeus Kulzer) on etched substrate; and group 4, iBond Self-Etch (control). Enamel and dentine bond strengths were calculated using microshear and microtensile bond-strength tests. Additional specimens were prepared to evaluate nanoleakage at the dentine-adhesive interface and were investigated using light microscopy or transmission electron microscopy. Both adhesives demonstrated higher microshear bond strengths when enamel was pre-acid-etched with phosphoric acid (Adper Easy Bond 28.7 ± 4.8 MPa; iBond Self-Etch 19.7 ± 3.6 MPa) compared with controls (Adper Easy Bond 19.2 ± 3.3 MPa; iBond Self-Etch 17.5 ± 2.7 MPa) and increased microtensile bond strength when applied on acid-etched (Adper Easy Bond 35.8 ± 5.7 MPa; iBond Self-Etch 24.3 ± 7.9 MPa) vs. smear-layer-covered dentine (Adper Easy Bond 26.9 ± 6.2 MPa; iBond Self-Etch 17.6 ± 4.3 MPa). Adper Easy Bond showed lower nanoleakage than iBond Self-Etch, irrespective of preliminary etching. The results of this study support the use of phosphoric acid etching before the application of one-step self-etch adhesive systems.
Abstract: To evaluate the accuracy of four electronic apex locators (EAL) in the apical region (0-3 mm short of the foramen) and to compare the precision of the readings on the display with the real position of the file in the root canal.
Abstract: Ceramic inlays and partial crowns have become scientifically recognized posterior restorations. Their clinical effectiveness depends on the development of durable dental ceramics and luting materials as well as an effective bonding system. Therefore, these factors were in the focus of interest in the past. In contrast, only little attention was given to preparation techniques. However, current studies show that special preparation rules should be followed to ensure best fitting CAD/CAM ceramic restorations and long-lasting clinical success. This paper describes preparation requirements by means of detailed three-dimensional schematic drawings and then deduces the clinical procedure for the preparation of ceramic inlays and partial crowns with standardized preparation instruments.
Abstract: This controlled prospective split-mouth study evaluated the clinical behavior of two different resin composites in extended Class II cavities over a period of four years.
Abstract: To evaluate the clinical behavior of two different resin composites in Class II cavities over a period of 2 years in a controlled prospective split-mouth study.
Abstract: The aim of the present study was to clinically evaluate the suitability of Definite Multibond and Definite ormocer resin composite for luting of Cergogold glass ceramic inlays in a two-center trial involving two dentists.
Abstract: In this controlled prospective clinical study the highly viscous glass ionomer cement Ketac Molar was clinically assessed in Class I and Class II cavities. Forty-nine subjects (mean age 32.3 years) received 108 restorations placed by six operators in conventional Black I and II type cavities with undercuts after excavating primary lesions or after removing insufficient restorations. At baseline, and after 6, 12, and 24 months, restorations were assessed by two independent investigators according to modified USPHS codes and criteria. Impressions of the restorations were taken and epoxy replicas were made. Between the baseline and the 24-month recall, 51 representative samples were analyzed at 130 x magnification by use of a stereo light microscope (SLM). Recall rates were 83% after 6 months, 50% after 12 months, and 24% after 24 months. Failure rates after 24 months were 8% for Class I and 40% for Class II fillings, mainly due to bulk fracture at occlusally loaded areas (Kaplan Meier survival analysis). Significant changes over time were found for the criteria "surface roughness", "marginal integrity", "restoration integrity", and "overall judgement" (P < .05; Friedman test). SLM analysis revealed statistically significant differences for the following criteria over time (baseline/6 months/12 months (in % of entire evaluable margin length); P < .05; Friedman 2-way ANOVA): perfect margin 37/19/11, negative step formation 26/49/57, gap formation 2/7/9, and overhang 24/11/8. Replicas exhibited mainly negative step formation as main finding due to apparently inferior wear resistance (P < .05). Gap formations were more frequently observed in Class II restorations than in Class I (12% versus 3% after 12 months; P < .05, Mann-Whitney-U test). The evaluated margin lengths were not statistically different (P > .05, Friedman 2-way ANOVA).
Abstract: To test the influence of thermomechanical loading and mode of cleaning the pulp chamber on coronal microleakage of adhesive sealings over root canal fillings.
Abstract: To calculate the probability of interface imperfections within SEM cross-sections of adhesively luted GFP depending on the level of analysis and the cement application method by means of LOM (light-optical microscopic evaluation method).
Abstract: Resin composite materials tend to accumulate microorganisms and dental plaque, which in turn may induce secondary caries around adhesive restorations. The aim of the present in vitro study was to evaluate the antibacterial activity of a resin composite material loaded with silver microparticles against Streptococcus mutans.
Abstract: The composite luting gap between ceramic and dental hard tissue can be termed an "Achilles heel". Therefore, one major goal of luting ceramics focuses on minimizing the inter-marginal gap area. This study evaluated the marginal accuracy of two all-ceramic systems. The null hypothesis was that there is no statistical difference between the marginal accuracy of the IPS Empress and Cerec 3D all-ceramic systems. On 16 casts, representing different clinical situations, the left first mandibular molar was prepared to receive large onlays (MOD and replacement of the distobuccal and distal cusps). For each cavity, one laboratory heat-pressed (IPS Empress) and one chairside CAD/CAM restoration (Cerec 3D) were manufactured. A newly developed milling unit was used for CAM processing. The restorations were placed in their respective cavities and die replicas were taken and examined under SEM for quantitative gap measurement. The gap width was measured at 11 defined landmarks by two different examiners. An overall gap width of 56 microm (+/- 31 microm) was measured for IPS Empress, compared to the significantly increased value of 70 pm (+/- 32 microm) for Cerec 3D. From a clinical viewpoint, the statistically significant difference between the two systems is not relevant, since both systems still exhibit a clinically acceptable gap width of less than 100 microm.
Abstract: To measure subcritical crack growth parameters in vitro and to correlate those with clinical observations from the 12 years recall of a prospective clinical study.
Abstract: To evaluate marginal integrity of IPS Empress inlays luted with different adhesives and cements before and after thermo-mechanical loading (TML).
Abstract: Adhesive luting of the final restorations is supposed to support the overall strength of post-endodontically restored teeth. For evaluating adhesive vs conventional cementation, the load capability of adhesively restored endodontically treated teeth (ETT) with glass fibre-reinforced composite posts (GFRCP), resin composite cores and all-ceramic crowns was determined. Thirty-two caries-free human upper, central incisors were randomly assigned to four groups, endodontically treated and cut 2 mm above the cemento-enamel junction. All teeth were restored with GFRCP, composite core build-ups and all-ceramic crowns. All-ceramic crowns were cemented with zinc phosphate cement (I), glass ionomer cement (II), and a self-adhesive resin cement (III and IV). After thermo-mechanical loading, the specimens were loaded to fracture. Maximum load capability F(max) and fracture patterns were compared using non-parametric statistics. Median values for the maximum load capability F(max) (minimum/maximum) in [N] were: I = 503 (416/1,038), II = 442 (369/711), III = 502 (326/561) and IV = 518 (416/652). No statistically significant differences were found for F(max) (p = 0.761) and fracture patterns (p = 0.094) between the experimental groups. The type of cementation of all-ceramic crowns, whether self-adhesive or conventional, appears to have no impact on the load capability of ETT restored with GFRCP and composite core build-ups.
Abstract: To evaluate the effect of different air-abrasion devices on substance loss on flattened enamel, preparation extent, and microleakage of invasive pit and fissure sealings.
Abstract: The aim of this study was to light microscopically evaluate the homogeneity of the cement interface of an adhesively luted glass fiber post (GFP) by using a new cement application aid compared to a conventional post cementation method.
Abstract: Self-etching adhesives partly remove or dissolve the dentin smear layer, causing incomplete resin tag formation or low resin tag density. The quantitative contribution of properly formed resin tags to dentin adhesion was evaluated.
Abstract: The aim of the present study was to clinically evaluate the effect of two different adhesive/resin composite combinations for luting IPS Empress inlays with a special focus on luting gap wear and marginal adaptation.
Abstract: This review thoroughly accumulated information regarding new technologies for state-of-the-art light curing of resin composite materials. Visible light cured resin-based composites allow the dentist to navigate the initiation of the polymerization step for each layer being applied. Curing technology was regularly subjected to changes during the last decades, but meanwhile the LED era is fully established. Today, four main polymerization types are available, i.e. halogen bulbs, plasma are lamps, argon ion lasers, and light emitting diodes. Additionally, different curing protocols should help to improve photopolymerization in terms of less stress being generated. Conclusions were: (1) with high-power LED units of the latest generation, curing time of 2 mm thick increments of resin composite can be reduced to 20 seconds to obtain durable results; (2) curing depth is fundamentally dependent on the distance of the resin composite to the light source, but only decisive when exceeding 6 mm; (3) polymerization kinetics can be modified for better marginal adaptation by softstart polymerization; however, in the majority of cavities this may not be the case; (4) adhesives should be light-cured separately for at least 10 seconds when resin composite is applied directly; (5) photocuring through indirect restorations such as ceramics is still a problem, therefore, both dual-cured adhesives and dual-cured composites and resin coating in any way are recommended; and (6) heat generation with high-power photopolymerization units should not be underestimated as a biological problem for both gingival and pulpal tissues.
Abstract: Recently, the appropriate, durable bond of adhesive systems and composite resin cements to retain endodontic posts was challenged. The question arises whether it would be possible to place glass fiber posts in a less technique sensitive conventional nonadhesive approach. The influence of nonadhesive, self-adhesive, and etch-and-rinse systems on load capability of postendodontic restorations was studied. Human maxillary central incisors were divided into 4 groups (n = 10). Teeth were endodontically treated and restored by using glass fiber posts luted with different cements/composite resin combinations: (1) RelyX Unicem (3M ESPE, Seefeld, Germany)/Clearfil Core (Kuraray Europe, Duesseldorf, Germany), (2) RelyX Unicem/LuxaCore, (3) zinc phosphate cement/Clearfil, and (4) LuxaCore (DMG, Hamburg, Germany)/Clearfil. A 2 mm-ferrule preparation was performed. All specimens received adhesively luted all-ceramic crowns and were exposed to thermal cycling and mechanical loading before subsequent static loading. Significant differences between the experimental groups regarding load capability and fracture patterns were observed. The conventional non-adhesive post cementation is less reliable to withstand simulated functional forces compared to adhesive approaches.
Abstract: This study evaluated the marginal quality of differently bonded direct resin composite restorations in enamel and dentin, before and after thermomechanical loading (TML). Special attention was focussed on the performance of selective enamel etching, etch-and-rinse, and self-etching adhesives.
Abstract: This controlled clinical trial aimed to evaluate IPS Empress inlays and onlays over 12 years. The null hypothesis was that different luting resins would have no influence on clinical outcome.
Abstract: The aim of the present study was to investigate the influence of the rigidity of different post materials (titanium versus glass fiber reinforced composite [FRC]) on the fracture resistance of endodontically treated teeth (ETT).
Abstract: To design an artificial mouth in order to evaluate if a new diagnostic tool (Clinpro Cario Diagnosis) can be used for early detection of secondary caries at resin composite margins in vitro.
Abstract: The aim of this study was to evaluate the influence of moisture on apical leakage using five different types of sealer. There were 120 single-rooted teeth instrumented to .02/#60 and randomly assigned to 10 experimental groups, one control group (AH Plus, lateral condensation) (n = 10) or positive/negative controls (n = 5). Before obturation teeth were dried thoroughly, followed by recontamination with moisture in a wet chamber (moist groups; 37 degrees C for 7 days). The teeth of the experimental groups (a, dry; b, moist) were obturated with sealer (groups 1, AH Plus; 2, Apexit; 3, Ketac-Endo; 4, RoekoSeal; 5, Tubli-Seal) and a single gutta-percha cone .02/#55. Teeth were centrifuged (30 x g for 3 minutes) in 5% methylene blue. Linear dye penetration was measured under a stereomicroscope. Moisture led to less microleakage for Apexit, RoekoSeal, and Tubli-Seal and higher values for AH Plus and Ketac-Endo. Multifactorial ANOVA displayed a significant dependence of leakage on sealer (p < 0.001) and the combination sealer or moisture (p < 0.01). It depends on the sealer type in which way moisture affects the apical seal.
Abstract: The restoration of carious primary teeth plays an underestimated role in paediatric dentistry. This is astonishing for many reasons, not least because many new materials have been introduced in recent years. New or modified techniques and materials, with better aesthetics and flexural properties, allow minimally invasive treatment. A transfer of techniques between different dentitions, however, may be problematic because of both micromorphological differences and compliance. Therefore, this paper deals with options for restoring primary teeth and the early stages of the mixed dentition using polyacid-modified composites, the so-called compomers.
Abstract: The common teaching goal of two different phantom head courses was to enable the students to provide an all-ceramic restoration by the means of computer technology. The aim of this study was to compare these two courses with regard to the different educational methods using identical computer software. Undergraduate dental students from a single year were randomly assigned to two different courses. One course was a conventional teacher-centred course [TRAD]. The other course contained problem-based learning (PBL) oriented structured modules [HYBRID]. The students completed an evaluation based on a 25 item seven-point Likert scale. Two independent evaluators assessed the practical work. Differences between TRAD and HYBRID were tested for significance using the Mann-Whitney U-test (at p < or = 0.05). Both courses were rated as demanding. The HYBRID group rated those items significantly better, which focused on course atmosphere and student-teacher relationship. The TRAD group felt that their course was more satisfying. Practical results of the two groups did not differ significantly. Within the limits of the study it was revealed, that the HYBRID group was less satisfied with the own success although the learning conditions were rated better. This could be interpreted in two ways: (1) the PBL oriented course lead the students to more self skepticism to their own work or (2) due to increased intellectual demands and the lack of detailed guidelines the course was felt as more burdening.
Abstract: Despite an overall caries decline in children, still 50-60% of carious primary teeth of 6-year-olds remain untreated, in 3-year-olds 13%. There are an increasing number of poli-caries patients with insufficiently treated primary teeth. Therefore, early treatment is fundamental.
Abstract: Air-polishing is routinely used for professional tooth cleaning. Therefore, the aim of this in vitro study was to evaluate the influence of different air-polishing powders on dentin bonding.
Abstract: To evaluate microtensile bond strength to Class I cavity floor dentin beneath adhesive inlays that were luted with different adhesives, temporary cements, cleaning methods, and curing modes.
Abstract: In vitro testing of dental materials is daily routine for the preclinical investigation of restoratives. Although clinical trials remain the ultimate instrument, preclinical screenings are still important. However, it is still not fully understood whether clinical performance is predictable in the lab. The aim of this paper is to combine known facts and recent results to answer the question concerning in vitro predictability of clinical marginal integrity and related outcome.
Abstract: The aim of this study was investigation of the opportunity of biomimetic growth of apatite on a dentine surface at various methods of its processing. Artificial blood human plasma--simulated body fluid (SBF)--was used as a source of ions. According to the scanning electronic microscope (SEM) and confocal laser scanning microscope (CLSM) and energy dispersive X-ray analysis (EDX) they have revealed the growth of crystals of calcium--deficient apatite. The structure of the formed apatite layer differed depending on a kind of processing of a dentine surface. After acid etching the globules of the apatite are located chaotically and the part of a dentine surface remains free. The removal of the collagen fibres by NaClO promotes uniform, controllable growth of crystals, forming a monolithic layer. The hypermineralisated areas of a tooth create the best conditions for growth. The transformation hydroxyl apatite in a superficial dentine layer can be caused by increasing of pressure at preparing with diamond bur. The growth of crystals of brushite in the smear layer is possible at a storage in water at 37 degrees capital ES, Cyrillic. The crystals have lamellar form and are well integrated in a dentin surface.
Abstract: The durability of bonding efficacy of composites with hard tissues of a tooth was investigated at application of one-bottle adhesive with total etching and five self-etching adhesives. The efficiency of etching by 36% orthophosphoric acid and acid components of self-etching adhesives was estimated. The adhesion between substrate and composite was measured by method of microtensile bond strength (mTBS). The control of efficiency of etching and depth of the penetration was carried out with the confocal laser scanning microscopy. It was established, that self-etching adhesives are capable to guarantee bonding of composites with enamel and dentine at a level compared with adhesives of the 5th generation. Deep adhesives penetration in dentine tubules is not the key factor for creation of reliable bonding.
Abstract: This investigation evaluated the stabilizing effect of glass fiber reinforced posts (FRP) luted with self-adhesive universal cement on the fracture resistance of excessively flared endodontically treated teeth (ETT). Values were compared to teeth with no ferrule, 2 mm ferrule and resin cement for luting with 2 mm ferrule. Thirty-two caries-free maxillary central incisors were randomly assigned to 4 groups (n=8) and endodontically treated. Two groups were flattened 2 mm above and 2 groups at the cemen-to-enamel junction (CEJ). The teeth received FRPs as follows: 1) post was cemented with self-adhesive cement (RelyX Unicem, 3M ESPE) (U), no ferrule (F) was prepared, root canal entrance was excessively flared with a remaining wall thickness of 0.5 - 0.75 mm (UNF/flared); 2) post was cemented with U, no F was prepared; 3) post was luted with U, F was prepared; 4) post was cemented with a resin cement (Panavia F, Kuraray, Japan), F was prepared. All specimens were built-up using a resin composite (Clearfil Core, Kuraray). All-ceramic crowns were adhesively luted (U). Specimens were exposed to thermo-mechanical loading and statically loaded until failure. The mean fracture load values [N](SD) were: UNF/flared=68 (126); UNF=315 (136); UF=488 (72); PF=860 (190). All groups exhibited statistically significant differences regarding maximum fracture load (p<0.05).
Abstract: Wear phenomena of ceramic inlays are not fully understood. The aim of the present study was to evaluate ceramic wear, antagonist enamel wear, and luting cement wear over 8 years. The two-fold null hypothesis was that there would be (1) no difference in wear behavior between ceramic and enamel, and (2) no influence of filler content of luting composites on composite wear. From 96 restorations, 36 Class II inlays from 16 participants were selected. For inlays with opposing enamel cusps (n=17), replicas of inlays and enamel were scanned with a 3-D laser scanner. Luting gaps of inlays (n=36) were analyzed with a profilometer, including 3-D data analysis. Ceramic and enamel wear increased between 4 and 8 years, with significantly higher values for enamel after 6 years (p<0.05). Luting gap wear increased continuously up to 8 years (p<0.05), with no influence of luting composites (p>0.05) and location of teeth (p>0.05).
Abstract: To clinically evaluate two polyacid-modified resin composites (Hytac and Dyract AP) for the restoration of posterior teeth over a 4-year period and to investigate accessible margins by light microscopy.
Abstract: The aim of this study was to evaluate the mechanical properties, such as Young's moduli, fracture strengths (FS), and flexural fatigue limits of todays resin composite dental restoratives. All materials have been subdivided into flowable, aesthetic hybrid and nano-filled hybrid composites as marketed by dental manufacturers and analyzed in terms of the actual filler configurations. Specimen bars have been manufactured in reference to ISO 4049 standard, light-cured for 20 s, and stored in distilled water before testing. The elastic moduli (EM), FS, and flexural fatigue limits (FFL) were measured after 14 days storage by using the four-point bending test. The FFL was determined for 10(4) cycles. The fatigue data were analyzed by using the "staircase" approach and statistically treated by ANOVA analysis. Flowable materials with a reduced filler content exhibited the lowest Young's moduli, compared with those measured for higher filled materials. A linear relationship has been found between elastic moduli and filler loading (r(2) = 0.798). Correlations of FS and fatigue data to different filler fractions could not be proved. FS ranged between 61.3 and 124.9 MPa. After 10(4) cycles of fatigue loading, the FS suffered from a decrease between 45.2 and 61.7%. However, materials providing high initial strengths do not obviously reveal the best fatigue resistance. A marketing-based grouping of direct restorative materials has no meaning toward laboratory testing of mechanical properties.
Abstract: The aim of the present study was to clinically evaluate the effect of two different adhesive/resin composite combinations for luting of IPS Empress inlays.
Abstract: Ceramic inlays and onlays are a tooth colored alternative to metallic restorations. Clinical long-term data are scarce though, especially about inlays and onlays having proximal margins in dentin. The present prospective controlled clinical study evaluated the clinical performance of IPS Empress inlays and onlays with cuspal replacements and proximal margins below the cementoenamel junction over eight years.
Abstract: The aims of this in vitro study were to evaluate the ultra-morphological changes in resin-dentine interfaces after different amounts of thermomechanical load (TML), and to determine the corresponding microtensile bond strengths (microTBS). Enamel/dentine discs with a thickness of 2 mm were cut from 24 human third molars and bonded with four adhesives involving different adhesion approaches: Syntac (Ivoclar Vivadent; used as multi-step etch-and-rinse adhesive), Clearfil SE Bond (Kuraray; two-step self-etch adhesive), Xeno III (Dentsply DeTrey; mixed all-in-one self-etch primer adhesive system), and iBond (Heraeus Kulzer; non-mixed all-in-one self-etch adhesive). The resin-dentine discs were cut into beams (width 2 mm; 2 mm dentine, 2 mm resin composite) and subsequently subjected to cyclic TML using ascending amounts of mechanical/thermal cycles (20 N at 0.5 Hz of mechanical load and 5-55 degrees C of thermal cycles: for 0/0, 100/3, 1,000/25, 10,000/250, 100,000/2,500 cycles). Loaded specimens were either cut perpendicularly in order to measure microTBS (n=20; crosshead speed: 1 mm/min) or were immersed in an aqueous tracer solution consisting of 50 wt% ammoniacal silver nitrate and processed for ultra-morphological nanoleakage examination using transmission electron microscopy (TEM). microTBS were significantly decreased by increasing amounts of TML for all adhesives (p<0.05). Bond strengths after 0 vs. 100,000 thermomechanical cycles were: Syntac: 41.3/30.1 MPa; Clearfil SE Bond 44.8/32.5 MPa; Xeno III 27.5/13.7 MPa; iBond 27.0/6.2 MPa. Relatively early, a certain amount of nanoleakage was observed in all groups by TEM, which was more pronounced for Xeno III and iBond. The incidence of nanoleakage remained stable or was even reduced with increasing load cycles for all adhesives except iBond, where exact failure origins were detected within the adhesive and at the top of the hybrid layer.
Abstract: To examine the ultrastructure of bonding to occlusal enamel fissures using phosphoric acid etching in combination with a pit and fissure sealant (Clinpro Sealant), a total-etch single-bottle adhesive (One-Step) followed by the fissure sealant, and two single-step self-etch adhesives (Adper Prompt and Xeno III) followed by the fissure sealant.
Abstract: The aim of this study was to evaluate the shear bond strength of three resin cements to Vita Mark II ceramics under different pretreatments of the ceramic surface and to examine whether simplified pretreatment procedures would result in satisfying results compared to the state of the art. RelyX Unicem (RXU), Calibra (CAL), and Variolink II (VAR) were used as resin cements and bonded to machine milled feldspatic disks, pretreated in five different ways. (1) no pretreatment of the ceramic surface; (2) surface etched with hydrofluoric acid (HF); (3) ceramic surface silanized; (4) ceramic surface etched (HF) and silanized, (5) ceramic surface etched (HF), silanized, and covered with Heliobond. The shear bond strengths were measured initially, after 5000 and 10,000 thermocycles (TC). After 10,000 TC for CAL only procedure 5 resulted in a reliable adhesion median value of 10.7 MPa. VAR showed median values of 24.6, 17.2, and 18.1 MPa for pretreatments 5, 3, and 4, respectively. RXU performed 25.9, 22.0, and 11.0 MPa for procedures 5, 4, and 3, respectively. For procedure 2, RXU revealed the significantly highest value with 15.4 MPa (U-test, p = 0.05). Only RXU-luted specimens of procedure 1 survived the 10,000 thermocycles. The results revealed that a simplification of the ceramic pretreatment for VAR and RXU might be possible.
Abstract: summary Ceramic inserts are reported to possibly reduce polymerization shrinkage for posterior resin composite fillings. The aim of the present investigation was to evaluate the effect of different insert systems before and after thermomechanical loading. Sixty sound human third molars received occlusomesial Class II cavities, 40 with proximal margins 2 mm above and 20 with proximal margins 1 mm below the cementum-enamel junction. The specimens were randomly assigned to one of the six experimental groups (n = 10). The enamel-bordered cavities were restored with Syntac classic and Tetric Ceram (ST), Syntac classic, Tetric Ceram and beta-quartz inserts (TB), Syntac classic, Tetric Ceram and Cerana inserts (TC), Syntac classic, Tetric flow and SonicSys approx inserts (TS). The dentin-limited cavities were filled with Syntac classic and Tetic Ceram (DT), Syntac classic, Tetric flow and SonicSys approx inserts (DS). Before and after thermomechanical loading (100 000 x 50 N, 2500 x 5 degrees C/55 degrees C), replicas were made and both interfaces tooth/composite and insert/composite were examined under a scanning electron microscope at 200x. The Cerana and SonicSys insert groups showed significantly less gaps in enamel (P < 0.05). With beta-quartz inserts, no reduction of gaps was found (P > 0.05). Marginal integrity in dentine-bordered specimens could not be improved with SonicSys inserts (P > 0.05). The bonding performance insert/composite was promising for all IPS Empress inserts (Cerana, SonicSys enamel) but worse for beta-quartz inserts. Regarding gap formation between resin composite and tooth, Cerana and SonicSys inserts significantly reduced gaps. The use of SonicSys inserts in deep proximal cavities cannot be recommended.
Abstract: To clinically evaluate two different resin-based composites (Solitaire I and Ariston pHc) in order to determine the minimum clinical evaluation time needed to detect critical signs of failure.
Abstract: This study provided morphological evidence that discrepancies between the depth of demineralisation and the depth of resin infiltration can occur in some mild self-etch adhesives. Sound dentine specimens derived from extracted human third molars were bonded with 5 one-step and 5 two-step self-etch adhesives. One millimeter thick slabs containing the resin-dentine interfaces were immersed in 50 wt% aqueous ammoniacal silver nitrate and processed for TEM examination. A zone of partially etched but uninfiltrated dentine was identified beneath the hybrid layers in the milder versions of both one-step and two-step self-etch adhesives. This zone was characterised by the occurrence of silver deposits along the interfibrillar spaces of mineralised collagen fibrils. The silver infiltrated interfibrillar spaces were clearly identified from the one-step self-etch adhesives Xeno III, iBond, Brush&Bond and the experimental adhesive, and were thinner and only occasionally observed in the two-step self-etch adhesives Clearfil SE Bond and Clearfil Protect Bond. The more aggressive one-step and two-step adhesives that exhibit more abrupt transitions from completely demineralised to mineralised dentin were devoid of these silver-infiltrated interfibrillar spaces beneath the hybrid layers. Incomplete resin infiltration observed in some self-etch adhesives may be caused by the reduced etching potential of the acidic monomers toward the base of hybrid layers, or the presence of acidic but non-polymerisable hydrolytic adhesive components, creating potential sites for the degradation of the bonded created by these self-etch adhesives.
Abstract: This study evaluated the marginal integrity of dentine adhesives bonded to enamel and dentine, before and after thermo-mechanical loading (TML).
Abstract: The aim of this in vitro study was to evaluate dentin bond strength and marginal adaptation of direct resin composite fillings after different storage times. Three hundred sixty cavities were prepared in discs of freshly extracted human third molars and filled with resin composites. Multistep self-etching adhesives (Syntac Classic, A.R.T. Bond, both with and without total etching), three-step etch-and-rinse adhesives (Scotchbond Multi-Purpose Plus, EBS), and two-step etch-and-rinse adhesives (Prime and Bond 2.0, Syntac Single-Component) were used for bonding. After 1, 90, and 2190 days of water storage and 24 h thermocycling (1150 cycles), push-out testing was performed. From the 6-year group, replicas were made after 1 day, 90 days, and 1, 2, 3, 4, 5, and 6 years, and examined regarding marginal adaptation under an SEM (x 200 magnification). In all groups under investigation, push-out bond strengths remained stable after 90 days; however, the strengths significantly decreased after 6 years of water storage. The two-step systems exhibited lower bond strengths than three-step systems after 6 years. Marginal analysis revealed a significant loss regarding the percentage of perfect margins having been stable after 2 years for the three-step etch-and-rinse systems. Overall, the older three-step systems proved to be more effective than the simplified adhesives Syntac Single-Component and Prime and Bond 2.0 with regard to bond strength and marginal adaptation.
Abstract: A fibre reinforced glass ionomer cement (FRGIC) for dental applications was loaded with 20 vol% short fibres (430 microm) with a glass composition in the system SiO(2)-Al(2)O(3)-CaF(2)-Na(3)AlF(6). The fracture toughness and the total energy release rate were examined. A 20% anisotropic fibre alignment was observed, perpendicular to the loading direction. An increase of fracture toughness of 140% and of total energy release rate of 440% was achieved compared to the unreinforced glass ionomer cement. Matrix-fibre interface reaction is supposed to exert the major influence on mechanical behaviour of FRGIC by controlling fibre pull-out and thus the total energy release rate.
Abstract: Fatigue as one of the major factors affecting three-body wear of resin composites is influenced by mechanical properties of the resin matrix. The aim of this in vitro study was to determine three-body wear (ACTA methodology), fracture strength, and Young's modulus of four veneering composites (Artglass old and new formula, Vita Zeta LC Composite, Targis) and one direct restorative composite (Z 100). Furthermore, three-body wear of the pure matrices of the materials was tested. The wear results were compared to Amalgam as reference material. It should be computed whether there exists a correlation between the wear results of resin composite and matrix alone. Wear of the veneering composites was significantly higher than of Z100 (13 microm) and Amalgam (14 microm; p < 0.01, Mann-Whitney U-test). Mean fracture strengths of indirect composites ranged from 127.5 MPa (Targis) to 71.6 MPa (Vita Zeta LC). The elastic moduli of the composites were between 2.9 and 12.8 GPa. The matrix wear rates did not differ significantly. Three-body wear results of complex resin composites are highly influenced by their filler content, filler particle size distribution, kind of filler particles, shape, and their silanization to the matrix. Due to this fact, three-body wear testing is an essential testing method and cannot be replaced by testing single material components.
Abstract: This study tested the hypothesis that single-bottle total-etch adhesives are effective in reducing dentine permeability under in vivo conditions.
Abstract: Due to polymerisation shrinkage of resin-based composites, a high configuration factor in deep Class I cavities leads to a certain amount of stress when the material is bonded. The aim of this in vitro study was to evaluate the influence of c-factor and different layering approaches on bonding to dentin with three different adhesive systems.
Abstract: Thrombotic thrombocytopenic purpura (TTP) is a rare haematological disease of unknown aetiology. This thrombotic microangiopathy is characterized by microvascular lesions with platelet aggregation. It is found in adults and can be associated with pregnancy, cancer, autoimmune diseases, bone marrow transplantation, drugs and bacterial as well as viral infections. The therapy requires a multi-disciplinary team approach involving dentistry. Even if TTP is immediately treated in an adequate manner, it still shows a mortality of up to 20%.
Abstract: The aim of the present case report was to define diagnosis and treatment options of a submental cutaneous sinus tract as a result of a progressive peri-implantitis around mandibular dental implants in a patient with a history of oral squamous cell carcinoma.
Abstract: The development of adhesive systems is briefly presented. The advantages of adhesively bonded ceramic restorations are discussed, as are the steps involved in creating an adhesive bond to ceramic.
Abstract: (1) To evaluate different pre-treatment modes for partial resin-based composite repair using a shear bond strength fatigue design on aged specimens, and (2) to investigate the effect of these pre-treatments on aged and partially replaced Class II resin-based composite restorations.
Abstract: The clinical performance of directly bonded resin composites is fundamentally dependent on durable adhesion to prevent gap formation over time. The goal of this investigation was to evaluate the effectiveness of various dentin adhesives by means of quasistatic and dynamic dentin bond strengths, and also to determine marginal and internal gap formation after loading in an artificial oral environment. Three hundred thirty human third molars were used within four weeks of extraction. Adhesives used were A.R.T. Bond, OptiBond FL, Scotchbond Multi-Purpose Plus, Single Bond, Prime & Bond NT, and One Up Bond F for bonding of one resin composite (Z 250). Buccal and lingual aspects of 90 teeth were ground flat to expose dentin, then resin composite cylinders were bonded. Initial bond strengths (n = 10) and adhesive fatigue limits (n = 20) were determined with the use of a shear test apparatus. One hundred eighty conical cavities were prepared into dentin discs and filled with the same materials. After 21 days of storage, initial push-out bond strengths (n = 10) and adhesive fatigue limits (n = 20) were measured. Sixty molars with MO cavities (n = 10) with margins below the cement-enamel junction were filled. Before and after thermomechanical loading (100000 x 50 N and 2500 x thermocycling between + 5 and + 55 degrees C), marginal gap formation and internal adaptation (only after loading) were analyzed under a SEM (x 200). The one-bottle systems showed higher shear bond strengths when evaluated statically and dynamically. However, cyclic fatigue push-out bond strengths resulted in higher values for older multistep systems. Marginal and internal gap analysis confirmed the results, in favor of older adhesive systems (p <.05; Mann-Whitney U test).
Abstract: Elastic modulus (EM), initial fracture strength (FS) and flexural fatigue limit (FFL) of dental restorative materials were measured in a simulated oral environment to correlate mechanical response under the influence of water with the chemical nature of the test materials under investigation. One resin composite (RC; Tetric Ceram, Ivoclar-Vivadent Corp., Liechtenstein), an ion-leaching resin composite (ILRC; Ariston pHc, Ivoclar-Vivadent Corp., Liechtenstein) a compomer (CO; Dyract AP, Dentsply Corp., USA) and a glass-ionomer cement (GIC; Ketac Molar, 3MEspe Corp., Germany) were tested. Static EM, FS and dynamic FFL experiments were performed. The FFL was determined under cyclic loading for 10(5) cycles in terms of a staircase approach. The materials were stored for 1, 8, 30, 90 and 180 days in 37 degrees C distilled water, respectively. The RC degraded over time due to water adsorption followed by failure within the resin matrix. The ILRC suffered from a pronounced decrease in FS as well as in FFL due to a constant ion-leaching and macroscopic crack growth. CO failed over time due to resin-filler interface cracking. The GIC exhibited improved mechanical performance over time due to a post-hardening mechanism. The results reveal the necessity for substantial preclinical evaluation of direct restorative materials. The material parameters under investigation are capable of predicting clinical performance over time.
Abstract: The aim of this study was to evaluate the mechanical properties of resin composite dental restoratives under quasi-static and cyclic loading.
Abstract: Complete removal of failed posterior resin composite fillings is time-expensive and involves the risk of removing sound tooth substance. In any case of failure within the composite material, intra-oral repair would be favourable. This in vitro study was conducted to examine the effect of different preparation and bonding modes on integrity of repaired restorations. Forty-eight direct Class II resin composite restorations (Syntac Classic/Tetric Ceram) were placed in extracted human third molars. The specimens were stored for 365 days and then replaced partially by removing the central part of the proximal box with all margins located in composite. The partial repairs were placed with the same materials after pre-treatment with a silicon carbide bur and Syntac Classic (n = 8). Preparation modes have been (i) box-only parallel, (ii) box-only with undercuts, (iii) box with undercuts and additional occlusal retention. The repairs were performed either with (i) Tetric Ceram or with (ii) Tetric Flow as thin lining covered with Tetric Ceram. Before and after thermomechanical loading (100 000 cycles of 50 N and 2500 cycles between +5 and +55 degrees C in an artificial mouth), marginal quality between aged and freshly applied composite was evaluated by SEM at x200 magnification and microleakage was observed by light microscopy at x50 magnification. Box-only preparations exhibited a better fatigue resistance than preparations with additional occlusal retention. This observation was independent from the presence of undercuts (P < 0.05). An intermediary layer of flowable resin composite tended to result in better marginal quality, however, not being statistically significant.
Abstract: The effect of filled adhesives on bonding resin composites to dentin has not been fully understood. Due to their filler content, filled adhesives may act as stress breakers. The aim of this in vitro study was to evaluate the use of flowable composites of different viscosities on bonding to enamel and dentin without the use of an intermediate bonding resin.
Abstract: To compare the adhesive capability of the new adhesive Prompt L-Pop (ESPE) with that of two total-etch adhesive systems-EBS Multi (ESPE) and Prime&Bond NT (Dentsply).
Abstract: The purpose of this in vitro study was to determine the influence of solvent and rewetting time on microtensile dentin bond strengths of four dentin adhesives.
Abstract: The resin composite Ariston pHc (pHc means pH control) was introduced as an alternative for fast amalgam replacement. The aim of the present study was to evaluate clinically the behaviour of this non-bonded resin composite material, promising the release of fluoride, calcium, and hydroxy ions, in comparison to a bonded resin composite (Solitaire I) in class I and II cavities. Ninety-nine cavities in 31 patients were restored in a controlled prospective clinical study. Fifty fillings were placed with Ariston pHc as per the manufacturer's instructions, i.e. neither with enamel etching nor with the use of rubber dam. The same patients received 49 Solitaire I restorations totally bonded with Solidbond using rubber dam. At baseline, after 6 months, and after 12 months, two investigators given the same instructions examined the restorations, according to modified USPHS codes and criteria. Forty selected restorations (20 Ariston, 20 Solitaire) were additionally analysed via replicas, using a stereo light microscope (SV 11, Zeiss, Germany) at 130x magnification. After 12 months, 95 restorations were rated clinically acceptable (6% failure rate for Ariston pHc; 2% for Solitaire). Statistically significant differences were computed for both materials regarding the criterion "filling integrity". Further statistically significant deterioration for Ariston pHc between the three evaluations has been detected for the criteria "tooth integrity" (enamel cracks) and "marginal adaptation" (gap formation/Friedman 2-way ANOVA; p<0.05). With Ariston the criterion "hypersensitivity" also increased significantly after 1 year in comparison to Solitaire. The microscopic margin analysis revealed significantly increasing marginal deficiencies over time for both materials regarding the criteria "perfect margin", "gap formation", and "negative step" (P<0.05; Friedman 2-way ANOVA).
Abstract: Aim of the present study was to evaluate the clinical suitability of the condensable metal-reinforced glass ionomer cement Hi-Dense in classes I and II cavities of primary molars.
Abstract: The effect of pre-treatment of composite inlays on bonding performance between a resin composite inlay and a luting composite has not been fully studied. The aim of the present study was to evaluate the influence of three different pre-treatment modes on fatigue bond strength and marginal adaptation. One hundred twenty resin composite discs (Tetric Ceram) were made as simulated inlays and randomly assigned to four groups (n=30): Without treatment (WT), hydrofluoric acid etching for 15 s + silanating (HF), roughening with a silicon carbide bur (SC), and silica coating + silanating (CO). Luting composite cylinders (Variolink II low) were bonded to the discs using Heliobond, and after 24 h in water at 37 degrees C, quasistatic shear bond strengths (n=l) and fatigue bond strengths (n=20; 5,000 cycles) were measured. Thirty-two third molars received occlusomesial Class II cavities (n=8), and direct resin composite inlays were luted with identical methods and materials. Before and after thermomechanical loading (100,000x50 N, 2,500 x +5 degrees C/+55 degrees C), replicas were made and examined (SEM, x200). CO and SC exhibited significantly higher bond strengths and adhesive fatigue limits than HF and WT (P<0.05). After thermomechanical loading, CO (98% continuous margin) and SC (95% continuous margin) demonstrated that they provide significantly more fatigue resistance than HF (88%).
Abstract: Wear of luting composites is still an unsolved problem with adhesive inlays. However, only limited clinical research has been conducted regarding this phenomenon. This study evaluated the substance loss within the luting gap over a six-year period in vivo. In the course of a controlled prospective clinical study, 16 patients received 39 Class-II IPS Empress inlays. Variolink Low (Vivadent; n = 18) was used as conventional low-viscosity luting composite, the hybrid-type restorative resin composite Tetric (n = 21; Vivadent) was applied according to the ultrasonic insertion technique. The restorations were clinically assessed after 6, 12, 24, 36, 48 and 72 months and replicas were made. The contact-free occlusal areas of the replicas were scanned by use of a computer-controlled profilometer (Perthen S3P), the analysis of the data was computed using a newly developed software (Xpert for Windows 95) and statistically analyzed with non-parametric tests. After six months all restorations exhibited marginal ditching. The percentage of detectable luting gap abrasion increased between each recall appointment (32% after six months, 48% after 12 months, 46% after 24 months, 55% after 36 months, 59% after 48 months and 65% after 72 months). Except for the 48-months results, no significant difference between the materials used for luting was evident (p > 0.05). Between the width and the depth of the luting space a linear regression was computed. The quantitative evaluation clearly demonstrated that hopes of relevantly reduced wear of luting composites were not confirmed when using the higher filled luting material.
Abstract: The purpose of this in vitro study was to examine shear bond strengths of composite resin to metal-exposed porcelain-fused-to-metal (PFM) and all-ceramic restorations after silica coating or etching with 5% hydrofluoric acid (HF). Specimens were fabricated for each of the following groups: two all-ceramic materials [a feldspathic porcelain (Vita Mark II) and a leucite-reinforced glass-ceramic (IPS Empress)], and one noble metal-ceramic (Orplid Keramik I alloy; Vita VMK 68 N felspathic veneer ceramic). These groups were repaired with resin composites after different pretreatment methods. In one metal-ceramic subgroup the surface exhibited a 50% metal and 50% ceramic exposure. In the silica-coating groups, the specimen surfaces were air abraded with silica acid-modified Al2O3 (CoJet Sand) and treated corresponding to the porcelain repair with resin composite. For control groups, the surfaces were etched with 5% HF for 60 seconds and treated in the same way as the silica-coated groups. After 24 hours of storage (distilled water, 37 degrees C) and an additional 24 hours of thermocycling (1150 x 5 degrees C/55 degrees C) the specimens were debonded using a shear bond strength test (n = 15). In all groups the silica coat repair achieved equal or significantly higher bond strengths than did the etching technique (p < 0.05, Mann-Whitney U test). In the metal-exposed group, the mean bond strength increased from 7.3 MPa to 16.3 MPa following the silica-coat repair. Results indicated that silica coating represents a suitable treatment for the intraoral repair of the materials tested in the present study.
Abstract: This in vitro study evaluated dentin bond strength and marginal adaptation of direct resin composites according to the manufacturers' instructions and with simulated application errors. One hundred and forty cavities were prepared into disks of freshly extracted human third molars and filled with one resin composite. Dentin adhesives of the third (with self-etching primer: Syntac Classic), fourth (with total etching: Scotchbond Multi-Purpose Plus) and fifth generation (one-bottle adhesive: Prime&Bond 2.1) were used for bonding. Simulated application mistakes were as follows: 1) prolonged etching; 2) excessive drying after conditioning; 3) drying primers immediately after application and 4) drying primers excessively. After 21 days of storage and 24 hours thermocycling (1150 cycles), replicas were made and push-out testing was performed. Replicas were examined for marginal adaptation using SEM (X200 magnification). Compared with values of the control groups, application errors resulted in dramatically decreased bond strengths and reduced percentages of gap-free margins for all products tested (p < 0.05). Excessive drying after conditioning exhibited significantly less effect for the third generation adhesive than for products requiring total etching/wet bonding.
Abstract: Ceramic inlays are an esthetic substitute for large amalgam and other metallic restorations. This controlled clinical study evaluated the performance of IPS Empress inlays and onlays with cuspal replacements and proximal margins below the cementoenamel junction over six years of clinical service. Six dentists placed 96 ceramic restorations in 34 patients. Luting was accomplished using the enamel-etch-technique, a dentin bonding system (Syntac Classic) and four different composite systems. The restorations were assessed by two calibrated investigators using modified USPHS criteria at baseline (96 restorations), one (96), two (95), four (89) and six years (67). Seven of the 96 restorations investigated had to be replaced (failure rate 7%; Kaplan-Meier): Five inlays suffered cohesive bulk fractures and two teeth required endodontic treatment. After six years of clinical service, significant deterioration (Friedman 2-way ANOVA; p < 0.05) was found for marginal adaptation of the remaining restorations. Ninety-four percent of the surviving restorations exhibited marginal deficiencies, independent of the luting composite. Neither the absence of enamel margins, nor cuspal replacement significantly affected the quality of the restorations.
Abstract: To describe the potential of adhesive luting procedures with respect to (1) material characteristics and classifications, (2) film thickness, (3) overhang control, (4) bonding to different inlay materials, (5) adhesion to tooth substrates and the problem of hypersensitivities, (6) wear of luting composites, and (7) clinical performance.
Abstract: The aim of this in vitro study was to compare the dentin bond strength and marginal adaptation of direct composite resins with and without additional NaOCl treatment after the etching process. A total of 150 cavities were prepared into disks of freshly extracted human third molars and filled with direct composite resins. Dentin adhesives of the fourth (with total etching: Scotchbond Multi-Purpose Plus, EBS, and Solid Bond), and fifth generation (one-bottle adhesives: Prime&Bond 2.1, Syntac Sprint) were used in combination with corresponding composite resin materials. Dentin disks without cavity preparation treatment served as controls. After 24 hours of storage and 24 hours of thermocycling (1150 cycles), replicas were made and push-out testing was performed. Replicas were examined regarding marginal adaptation using SEM (X200 magnification). In general, fourth-generation dentin adhesives produced better results in bond strength and marginal adaptation than fifth-generation one-bottle systems (P < 0.05). Within the fourth generation, Scotchbond Multi-Purpose Plus and EBS achieved significantly higher push-out values and percentages of gap-free margins than Solid Bond (P < 0.05). After hypochlorite treatment, dentin bond strength (-25%) and marginal adaptation (-30%) decreased significantly (P < 0.05) in all groups.
Abstract: The acid-etch-technique has provided an ideal surface for bonding to enamel by using 30-40% phosphoric acid. The resulting etch pattern is characterized by the profuse formation of microporosities which allow the penetration of monomers into those porosities to form resin tags that provide micromechanical retention. Successful attempts of bonding to dentin in a similar fashion have been reported more recently. Due to the specific properties of dentin, such as its tubular structure and its intrinsic wetness, bonding to dentin has not yet reached the ideal characteristics. In spite of the existing deficiencies in dentin adhesion, the increasing demand for esthetic restorations has generated intensive research on new esthetic materials with special focus on amalgam alternatives. The bonding mechanism of recent dentin bonding agents is based on the penetration of ambiphilic molecules into acid-etched dentin to form a lacework of dentin collagen and polymerized monomers. Dentin adhesive systems that contain a multitude of different bottles of different colors and shapes belong to the past. Because clinicians are increasingly eager to try new materials, the actual tendency calls for simplification of the bonding procedure e.g. one-bottle adhesive systems and all-in-one no-bottle materials. In spite of simpler materials, a separate etching step is still needed for one-bottle systems. Nevertheless, manufacturers of these simplified one-bottle materials recommend their use to bond polyacid-modified composites (compomers) without a separate etching step. The most recent addition to the group of simplified adhesives is the all-in-one no-bottle adhesives; one of these all-in-one systems, Prompt L-Pop (ESPE) has resulted in very promising laboratory results when used on enamel. In spite of the uncertainty about the capacity of all-in-one adhesives to etch enamel adequately in vivo, scanning electron microscopy studies have resulted in an enamel-etching pattern morphologically similar to that corresponding to phosphoric acid-etched enamel. While all-in-one adhesive systems have been reported to result in very satisfactory dentin bond strengths, results from other laboratories suggest that bonding to dentin with all-in-one adhesive systems will need to be somewhat improved. Clinical studies, which are the ultimate test for the acceptance of dentin adhesives, are now underway in several centers. Six-month data showed a very good clinical performance for this ultra-simplified all-in-one adhesive system.
Abstract: Contamination of etched enamel with dentin adhesive systems is unavoidable in clinical situations. The aim of this in vitro study was to evaluate the long-term effect of dentin adhesives and application technique on resin composite bond strength and marginal adaptation to enamel. Six hundred freshly extracted mandibular bovine incisors were used. Three hundred teeth were flat ground, and the enamel was etched for 30 seconds with 32% phosphoric acid. The etched surface was treated by different dentin adhesive systems with and without intensive rubbing by use of application brushes. As a control, only the enamel adhesive resin was applied and air thinned. Furthermore, contamination with saliva was performed after the etching process. Etched and silanated CEREC blocks were bonded onto the enamel specimens with different adhesive resins and stored for 1 and 365 days (37 degrees C, aqua dest). After storage, the specimens were thermocycled for 24 hours (1150 cycles between 5 degrees C and 55 degrees C), and subjected to shear bond testing. Three hundred box-shaped cavities were prepared on buccal surfaces of the incisors and filled with one resin composite using the same pretreatment modes as in the shear bond test groups. After 1 and 365 days of storage, a margin analysis was performed using a SEM (X200 magnification). Dentin adhesive systems did not show an adverse effect on long-term enamel bond strength and marginal adaptation. Rubbing application of the primers decreased the bond strength by values of approximately 20% after 24 hours and approximately 40% after 1 year of storage. Marginal adaptation showed 94-98% gap-free margins in the control and dentin adhesive system-only groups; however, after rubbing of primers, the proportion of gap-free margins decreased significantly to 85-88%. The lowest bond strength (8-10 MPa) and margin quality (49-69% gap-free margins) were recorded for the groups with saliva contamination.
Abstract: The aim of this in vitro study was to compare quasistatic and cyclic fatigue dentin bond strength of modern adhesive systems representing different generations. One hundred and fifty cavities were made in discs of freshly extracted human third molars and filled with direct resin composite restorations. Dentin adhesives of different generations (SY = Syntac Classic, multi-step system with self-etching primer; SE = Syntac Classic with additional phosphoric acid etching prior to application of the self-etching primer; SB = Scotchbond Multi-Purpose Plus, multi-step system with total etching; PE = Prime & Bond 2.1, single-step system with and without [PB] total etching) were used in combination with one hybrid composite. After 21 days of storage, 10 specimens for each adhesive system were subjected to thermocycling (1150 cycles) for 24 h and were afterwards debonded in a push-out test. Another 20 specimens were tested with cyclic fatigue according to the staircase method with 5000 cycles for each specimen. Static and cyclic push-out bond strengths, respectively, for each group were (MPa): SY 16.9 +/- 0.9 and 14.2 +/- 1.7, SE 17.5 +/- 1.8 and 14.8 +/- 3.4, SB 18.5 +/- 1.7 and 13.9 +/- 2.1, PB 14.6 +/- 2.2 and 7.2 +/- 2.4, PE 13.4 +/- 2.2 and 6.8 +/- 1.8. Both quasistatic and dynamic bond strengths revealed better values for the multi-step systems (P < 0.05). All adhesive systems tested revealed a significant fatigue behaviour which was more pronounced for the one-bottle system with a decrease of about 50% independent of additional dentin etching.
Abstract: The aim of this in vitro study was to compare the dentin bond strength and marginal adaptation of directly and indirectly inserted restorations. A conically modified push-out test was designed to consider polymerization shrinkage and facilitate inlay placement. A total of 260 cavities were prepared into disks of freshly extracted human third molars and filled with direct composite resins or with adhesively luted ceramic inlays. Dentin adhesives of the third--(with self-etching primer: ART Bond, Syntac Classic), fourth--(with total etching: Scotchbond Multi-Purpose Plus), and fifth-generation (one-bottle adhesives: Syntac Single Component, Prime & Bond 2.1) were used in combination with one hybrid composite (Tetric) or luting composite (Variolink Low). Control groups did not use an adhesive. Polymerization of the bonding agent was carried out prior to insertion of the filling/inlay or afterwards simultaneously with the composite/luting composite. The thickness of the adhesive layer and luting composite was recorded, and after 7 days of storage and 24 hours of thermocycling (1150 cycles) replicas were made and extrusion testing performed. Fracture modes were determined and replicas were examined regarding marginal adaptation using SEM (X200 magnification). Precuring of the bonding resin increased dentin bond strength independent of the material combination or insertion mode (P < 0.05). In general, third- and fourth-generation dentin adhesives produced better results in bond strength and marginal adaptation than one-bottle systems (P < 0.05). In the third generation, ART Bond achieved significantly higher push-out values than Syntac (P < 0.05), but no better marginal adaptation. Cohesive fractures within the dentin were only observed in the inlay groups with precured resin. Precuring of the bonding resin is an important factor for both direct and indirect restorations. Nevertheless, precuring of the bonding resin prior to insertion of adhesive inlays cannot be recommended clinically, because the 120-micron luting spaces were too large. In simulated cavities, direct composite fillings with precuring achieved bond strengths similar to inlays without precuring. One-bottle adhesive systems performed poorly compared with multi-step adhesives of the third and fourth generation.
Abstract: Ceramic inlays are used as esthetic alternatives to amalgam and other metallic materials for the restoration of badly damaged teeth. However, only limited clinical data are available regarding adhesive inlays and onlays with proximal margins located in dentine. In a prospective, controlled clinical study, the performance of IPS Empress inlays and onlays with cuspal replacements and margins below the amelocemental junction was examined.
Abstract: The aim of this in vitro study was to evaluate various core build-up and luting materials regarding their effect on crack formation of all-ceramic crowns.
Abstract: The aim of the present in vitro study was to evaluate different restorative concepts for posterior resin composite fillings in terms of internal adaptation and overhang formation. Eighty standard occluso-distal cavities with and without a 1.5-mm bevel were restored in a phantom head using Syntac Classic and Tetric Ceram with and without Tetric Flow as thin lining or Solid Bond and Solitaire with and without FlowLine. The restorations were finished intraorally and afterwards subjected to thermal loading (1150 x +5 degrees C/+55 degrees C) for 24 h. The proximal margins of the original specimens were analyzed for overhangs under a stereo light microscope (100-fold magnification) before and after intraoral control with loupes, including additional polish. Afterwards the teeth were cut longitudinally, replicated, and their internal integrity analyzed under a SEM (200-fold magnification). The combination of flowable and viscous composites resulted in enhanced internal adaptation for both adhesive systems. However, Syntac Classic exhibited superior adaptation characteristics compared with Solid Bond. In terms of overhang formation, the use of flowable materials always led to higher percentages of marginal overhangs in beveled cavities. Higher viscous materials alone resulted in higher percentages of underfilled margins of beveled than box-shaped cavities. It was clear that the use of magnifying glasses during finishing was beneficial for reducing marginal overhangs up to 40%.
Abstract: Syntac Sprint is a new one-bottle adhesive based on the total-etch and total-bond technique. The aim of this study was to compare the new restorative system consisting of Syntac Sprint and the resin composite Tetric Ceram with the clinically proven combination of the dentin adhesive Syntac Classic and the resin composite Tetric.
Abstract: Glass-ionomer cements offer advantages in the treatment of the primary dentition. New, colored, highly viscous glass-ionomer cements hold the promise of better abrasion properties. Owing to their high viscosity, their handling characteristics are similar to those of amalgam. Examination of their properties demonstrated increased resistance to abrasion in comparison to amalgam, although no improvement in fatigue or flexural resistance was found. Clinical experience extending over 2.5 years confirmed these results.
