Abstract: AIM: A new and innovative therapeutic concept using a light-induced fluorescence evaluator for diagnosis and treatment (LIFEDT) of dental caries based on the imaging and autofluorescence of dental tissues is proposed. The aims of this series of in vivo experiments are to compare and analyze the brightness variations of sound dentin and active and arrested carious dentin illuminated with an intraoral LED camera and to determine if this new device could be helpful in daily practice to discriminate between caries and sound dentin. METHODS AND MATERIALS: A new intraoral LED camera that emits visible blue light was used in this in vivo study to illuminate and photograph 15 teeth at high magnification. The magnified images were examined using the free Image J V version 1.41 software. Four standardized rectangular areas were drawn on each picture that included both healthy and pathologic areas to analyze variations in brightness using a brightness formula: L = 0.299 Red + 0.587 Green + 0.114 Blue. RESULTS: Statistically significant differences in the brightness were found between active and arrested caries processes in an area of infected dentin designated Z2. Within the limitations of this in vivo study, the images created with the intraoral LED camera revealed significant variations in fluorescence between sound dentin and active and arrested caries processes. CONCLUSIONS: The LIFEDT concept provides a therapeutic concept based on these findings of variations in fluorescence between healthy and pathologic tissue. CLINICAL SIGNIFICANCE: This concept defines a pragmatic clinical and therapeutic approach for treating active and arrested carious lesions based on the interpretation of variations of a fluorescence signal and applying the LIFEDT concept to the treatment of dentin carious lesions.
Abstract: This study compared the marginal adaptation of Class II open-sandwich restorations with an RMGIC versus a dual-cure composite as dentin substitute. Class II cavities were prepared on 50 extracted human third molars. The teeth were randomly assigned to two groups of 25 teeth to compare one dual cure composite (Multicore Flow) with one resin-modified glass-ionomer cement (Fuji II LC) in open-sandwich restorations covered with a light cure composite. The teeth were thermomechanically cycled (2000 cycles, 5 degrees C to 55 degrees C; 100,000 cycles, 50 N/cm2). The specimens were then sealed with a 1 mm window around the cervical margin interface. Samples were immersed in a 50% w/v ammoniacal silver nitrate solution for two hours and exposed to a photodeveloping solution for six hours. The specimens were sectioned longitudinally and silver penetration was directly measured using a light microscope. The results were expressed as a score ranging from 0 to 3. The data were analyzed with a non-parametric Kruskall and Wallis test. The degree of leakage significantly increased with Multicore Flow (median = 2) compared to Fuji II LC (median = 1). The resin-modified glassionomer cements remain the best intermediate materials when open-sandwich restorations are indicated. A comparison of the degradation of these materials over time remains a topic to be investigated by future studies.
Abstract: The current study compared the marginal adaptation of Class II open-sandwich restorations with a RMGIC versus a dual-cure composite as dentin substitute. Class II cavities were prepared on 50 extracted human third molars. The teeth were randomly assigned to two groups of 25 teeth to compare one dual cure composite (MultiCore Flow) with one resin-modified glass-ionomer cement (Fuji II LC) in open-sandwich restorations recovered with a light cure composite. The teeth were thermomechanocycled (2000 cycles, 5 degrees C to 55 degrees C; 100,000 cycles, 50 N/cm2). The specimens were then sealed with a 1 mm window around the cervical margin interface. Samples were immersed in a 50% w/v ammoniacal silver nitrate solution for two hours and exposed to a photo-developing solution for six hours. The specimens were sectioned longitudinally and silver penetration was directly measured using a light microscope. The results were expressed as a score from 0 to 3. The data were analyzed with a non-parametric Kruskal and Wallis test. The degree of leakage significantly increased with MultiCore Flow (median 2) compared to Fuji II LC (median 1). Resin-modified glassionomer cements remain the best intermediate material when open-sandwich restorations are indicated. A comparison of the degradation of these materials over time remains a topic to be investigated by future studies.
Abstract: AIM: The objective of this in vivo experiment is to propose an innovative therapeutic concept using a light-induced fluorescence evaluator for diagnosis and treatment (LIFEDT) that is based on the imaging and autofluorescence of dental tissues. BACKGROUND: Processes with the aim of diagnosing carious lesions in the initial stage with optimum sensitivity and specificity employ a wide variety of technologies, but like the conventional diagnosis tools, they remain either inefficient or too subjective. TECHNIQUE: This experiment evaluated a fluorescence light-induced camera that illuminates tooth surfaces within an excitation radiation band of light with a wavelength of 450 nm and facilitates a high magnification image. CONCLUSION: An analysis of 50 occlusal grooves revealed three clinical forms of enamel caries: (1) enamel caries on the surface, (2) suspicious grooves with a positive autofluorescent red signal, and (3) suspicious grooves with a neutral fluorescent dark signal. Two decision-making diagrams were proposed in accordance with international recommendations for preventive dentistry, but modified as a result of the accurate information obtained with this new LIFEDT device. CLINICAL SIGNIFICANCE: The lighting of suspect occlusal grooves with the SoproLife camera enables observation of any variations in the optical properties to refine a caries diagnosis and facilitates more than a 50x magnification of occlusal groove anatomy to provide additional information on the carious potential of the tooth surface.
Abstract: AIM: Within the context of minimally invasive dentistry this article describes the sonic and ultrasonic cavity preparation techniques and assesses their advantages and disadvantages, clinical difficulties of their use, and offers a statement about these devices. BACKGROUND: Ultra-conservative Class 2 restorative techniques require the use of devices such as sonic and the new ultrasonic preparation systems. These systems, featuring a series of sonic and new ultra-sonic inserts, allow for the fabrication of preventive preparations on proximal surfaces without injuring the adjacent proximal surface or damaging the marginal ridge. REVIEW: An ultraconservative approach to the restoration of teeth with proximal caries that lack frank occlusal cavitation is facilitated by the use of slot-style cavity preparations created with sonic and ultrasonic instrumentation, and esthetic restorative materials. SUMMARY: New restorative procedures appear suitable for use in ultraconservative restorative dentistry. More frequent use of these procedures by dental practitioners could prevent the traditional breakdown of the marginal ridge when preparing a Class 2 dental restoration. When cautiously used, these two ultraconservative devices provide alternative operative procedures to treat carious lesions without frank occlusal cavitation and to promote another aspect of preventive dentistry. CLINICAL SIGNIFICANCE: New restorative procedures appear suitable for use in ultraconservative restorative dentistry. More frequent use of these procedures by dental practitioners could prevent the traditional breakdown of the marginal ridge when preparing a Class 2 dental restoration.
Abstract: AIM: The aim of this study was to examine clinically relevant data on four restorative procedures for non-carious cervical lesions using United States Public Health Service (USPHS)-compatible clinical and photographic criteria and to compare different methods of analyzing clinical data. METHODS AND MATERIALS: Fourteen patients with at least one or two pairs of non-carious lesions under occlusion and a mean age of 50 were enrolled in this study. A total of 56 restorations (14 with each material) were placed by three experienced, calibrated dental practitioners. Two other experienced and calibrated practitioners, under single-blind conditions, followed up on all restorations for a period of one year. Three materials were randomly placed: a micro-hybrid composite with two polymerization methods (G1 and G2), a flowable micro-hydrid composite (G3), and a resin-modified glass ionomer (G4). Statistical analysis was performed using the Kruskall-Wallis test (p<0.05) and a Mann-Whitney U modified test with a corrected significance level. RESULTS: At the one year evaluation time, there were no restorations with secondary caries and the retention rates in G1 (IntenS with a hard polymerization), G2 (IntenS with a soft polymerization), G3 (Filtek flow), and G4 (Fuji II LC) were 85.7% (two losses), 92.8% (one loss), 100%, and 100%, respectively. The total visual comparison of the results at baseline (15 days later) showed significant differences only with the clinical acceptance criterion: G1 was different from G2, with a soft polymerization device (p<0.05). In terms of surface quality at one year, G1, G2, and G3 exhibited a statistically significant difference from G4, p<0.05. The digital analysis at baseline showed significant differences only with the clinical acceptance criterion: G1=G2 was different from G3=G4, p<0.05. At one year, only the microporosity criterion showed any statistical differences: G1=G2=G3 was different from G4, p<0.05. CONCLUSIONS: The resin-modified glass ionomer was easier to use and had a high retention rate, but it failed in terms of surface quality (visual mode) and porosity (digital mode) criteria compared to the others groups. Overall results showed no difference between groups G1 (hard-polymerized) and G2 (soft-polymerized), and only G1 was affected by the marginal edge (p<0.03) and integrity criteria (p<0.02) at one year.
Abstract: PURPOSE: To test how the number of sections affects the maximum depth of tracer penetration. MATERIALS AND METHODS: This study was simultaneously performed in three different centers. C-shaped Class V cavities were made on 60 human third molars. The cavities were located across the cementum-enamel junction. One restorative system was used: Scotchbond Multi-Purpose and Z100. After restoration, the samples were thermally cycled 3000 times, between 5 and 55 degrees C with a dwell time immersion of 10 seconds. Silver nitrate was used by two centers and basic fuchsin was used by the third. The teeth were longitudinally sectioned with a diamond saw: 5 sections per tooth provided 10 surfaces for evaluation. The penetration of the tracer was recorded on a scale from 0 to 3. The deepest leakage per restoration was identified for comparison with lesser measured values elsewhere in the tooth. The Spearman test was applied to evaluate the relationship between the reference and data from one, two and three sections (i.e. two, four and six measurements). The Kruskal-Wallis test was applied to compare the three centers. RESULTS: Whatever the study center, the Spearman correlation coefficient (r(s)) increased as a function of the number of sections (S) up to three: Center 1 (1S, 0.47; 2S, 0.68; 3S, 1.0), Center 2 (1S, 0.60; 2S, 0.99; 3S, 0.99), Center 3 (S1, 0.40; 2S, 0.73; 3S, 1.0). No statistically significant difference was found between the three study centers.
Abstract: The aim of this study was firstly to determine and compare the ability of inexperienced junior dental students (Fourth-year) and senior students (Fifth-year) versus a dental school instructor to identify demineralized dentine with the aid of a caries-disclosing solution and secondly to evaluate an eventual improvement of the caries diagnosis accuracy of junior (Fourth-year) and senior (Fifth-year) dental students. Three successive stages were used to check the ability of the dental students to diagnose and excavate the de-mineralized dentine. This study pointed out that 96% of junior dental students versus a teacher failed to remove all of the demineralized dentine without the use of a caries detector at the first stage and 79% at the second stage in the same condition. 100% of senior students versus a teacher, also failed to diagnose dental caries without a caries detector, but only at the first stage. However, at the second stage, unlike the junior students, all of the senior students were able to remove all of the demineralized dentine. Without the use of a caries detector dye, the risks of the dental students leaving demineralized dentine are high. This technique may be particularly helpful for the fourth-year students who are performing their first restorative treatment.
Abstract: PURPOSE: This study was undertaken to evaluate several polymerization and filling procedures (incremental, bulk, light-tip, soft-cured, plasma devices) in Class II restorations through (1) a sealing evaluation of restorations filled with Tetric Ceram (TC) and Bisfil 2B (B2B, self-cured composite used as a control), (2) a FTIR analysis measuring the variations of the degree of conversion in terms of area unit ratio of the relevant resin composites and (3) a microhardness test to corroborate the FTIR analysis. MATERIALS AND METHODS: The length of the tracer penetration was measured from the gingival margin up to the cavity wall with an episcope on sectioned teeth. A ceramic mould, simulating a Class II, was filled according to the different groups and the samples were analyzed with a Bruker IFS 55 spectrometer on ultrathin sections (3 mu). The results were analyzed in terms of area unit ratio and total exposed energy. Under the same conditions, a microhardness test was run with a Frank Weihem machine. RESULTS: The results of the sealing evaluation for light-tip, incremental and self-cured techniques did not differ. The plasma procedure failed in this evaluation as the bottom increment was not polymerized. The smallest area unit ratio (the best degree of conversion) was observed in 2 groups: one, the combination of the light-tip and soft process, and two, the self-cured resin composite (B2B). The distance at which the plasma procedure failed to cure the resin composite was between 3.5 and 4.5 mm. The microhardness test confirmed the FTIR analysis except for the group G2 (TC + light-tip). As also shown by FTIR analysis, no difference between the two relevant levels was observed with the hardness test. CONCLUSION: The dentin marginal sealing efficiency of Tetric Ceram restorations was increased with the light-tip technique, but was not better than the self-cured resin composite (B2B). For Tetric Ceram, the combination of the light-tip and soft process leads to a higher degree of conversion than the other groups. There is no linear relationship between the degree of conversion, the microhardness and the total exposed energy. The combination of the soft polymerization and the light-tip device might be an alternative restorative technique to the current incremental technique.
Abstract: The purpose of this study was to compare two implantation sites--the mandible and the femur of the rabbit--for testing in vivo intraosseous biocompatility. Twenty-two new Zealand rabbits were anesthetized, and the mandibular and femur bones were exposed. A hybrid glass ionomer cement or zinc oxide eugenol cement was loaded into silicone carriers and inserted into the two bones after drilling the two cortical plates. Eleven rabbits were killed 4 wk after implantation, and 11 rabbits were killed after 12 wk. The mandibles and femurs were prepared using standard histological procedures; tissue reactions were graded from none to severe. At 4 wk, no statistically significant difference was found between the two implantation sites. After 12 weeks, bone healing was statistically better in the mandible than in the femur. The mandible seems to be a better implantation site in the case of intraosseous implantation tests. The intraosseous biocompatibility of Vitremer was similar at 4 wk and superior at 12 wk to that of Super-EBA.
Abstract: OBJECTIVES: This study compared the intraosseous biocompatibility of Vitremer, a new hydrophilic glass-ionomer cement, to that of Super EBA. STUDY DESIGN: Twenty-two New Zealand rabbits were anesthetized, the mandibular bone exposed, and two holes were drilled through the cortical plate. The materials were loaded into silicone carriers and inserted into the mandibles. Eleven rabbits were killed 4 weeks after implantation, 11 animals after 12 weeks. The mandibles were prepared with standard histologic procedures; the tissue reactions were graded from none to very severe. RESULTS: At 4 weeks Vitremer implants showed very slight to slight reactions, and the Super EBA implants showed slight reactions and one moderate reaction with no significant difference between the two materials. At 12 weeks, bone healing had occurred, despite the persistence of some fibrous tissue interposition. The reactions were classified as none to very slight for Vitremer and very slight to slight for EBA. Statistical analysis showed better results for Vitremer at 12 weeks. CONCLUSION: The intraosseous biocompatibility of Vitremer was similar at 4 weeks and superior at 12 weeks to that of Super EBA. Its other properties should be evaluated before considering its use in clinical practice.
