Linear and volumetric gain after vertical bone augmentation in the posterior mandible using an autologous cortical tenting method.

This study was performed to evaluate the linear and volumetric effects of a technique for reconstruction of the posterior atrophic mandible, including the final bone gain of the graft, by three-dimensional assessment. Thirteen individuals were recruited into the study and submitted to a total of 15 mandibular autogenous bone block surgeries. Cone beam computed tomography images were obtained at three different times. Bone graft length and thickness, and the volume, height, and width of the graft were measured. Data were compared statistically among the time points using the Friedman test, and cluster analysis was performed to identify the association between the study variables and the resorption rate (α = 0.05). Linear analysis of the width and height of the recipient area at the different time points revealed a statistically significant difference. The final average increase in height was 1.6 mm; all subjects showed an average volume gain of 3.412mm3, and 77% of the subjects showed an average graft resorption of 0.688mm3 construction of three-dimensional vertical defects of the posterior mandible resulted in good healing with minimal complications and minimal bone graft resorption, favouring vertical bone gain.

Surface roughness assessment of resin-based materials during brushing preceded by pH-cycling simulations.

This study evaluated the surface roughness pattern of resin-based restorative materials during brushing preceded by a regimen that simulated a dynamic pH-cycling. Restoratives included two resin composites (Renamel Microfill and Charisma), two polyacid-modified composite resins (Compoglass-F and Dyract AP) and one resin-modified glass ionomer cement (Fuji II LC Improved). Twenty standardized cylindrical specimens of each material were prepared according to a randomized complete block design. After finishing and polishing, the average surface roughness (Ra) and profile-length ratio (LR) of the specimens were determined. The experimental units were subjected to a pH-cycling regimen, and then to 10,000 brushing strokes. New readings of both the Ra and LR parameters were obtained. The same protocol of pH-cycling, brushing simulation and surface roughness measurements were repeated 10 times. Data was analyzed using ANOVA according to split-plot design and Tukey's test. Results showed the pH-cycling followed by 10,000 brushing strokes provided a remarkable increase in Ra for all restorative materials except for Renamel. Throughout the brushing simulation, Renamel, Charisma, Compoglass-F and Dyract AP showed steady textures, whereas Fuji II LC Improved exhibited a progressive increase in surface roughness. Among the materials tested, Renamel presented the smoothest surface, followed by Charisma and Compoglass-F, which did not differ from each other except at the baseline. Dyract AP was different from both these materials except at the baseline. Fuji II LC Improved had the roughest surface texture.

Effect of fluoride gels on micromorphology of resin-modified glass-ionomer cements and polyacid-modified resin composites.

OBJECTIVE: The purpose of this study was to evaluate the surface micromorphology of resin-modified glass-ionomer cements and polyacid-modified resin composites subjected to a neutral sodium fluoride (NNaF) and an acidulated phosphate fluoride (APF) gel application. METHOD AND MATERIALS: Thirty standardized cylindric specimens were randomly obtained from each of two resin-modified glass-ionomer cements-Fuji II LC Improved and Photac-Fil Aplicap-and two polyacid-modified resin composites--Dyract and F2000-amounting to 120 samples. After 1 week, the specimens were finished and polished with aluminum oxide disks. Surface treatments with fluoride gels, or distilled water as a control, were performed four times, interspersed with eight pH cycles, simulating high cariogenic challenges. Five calibrated evaluators assessed the surface micromorphology through photomicrographs. RESULTS: The Kruskal-Wallis test showed no significant difference between the control and experimental groups for Fuji II LC Improved and Dyract. Photac-Fil Aplicap showed less micromorphologic change as a result of distilled water application, unlike the NNaF and APF treatments, which revealed no significant difference from each other. For F2000, there was no significant difference between the surfaces treated by NNaF and distilled water; the highest degradation occurred with the APF. CONCLUSION: Both the resin-modified glass-ionomer cements and the polyacid-modified resin composites showed erratic behaviors concerning their micromorphology when subjected to fluoride gel application.

In vitro microleakage of glass-ionomer composite resin hybrid materials.

The purpose of this study was to evaluate the microleakage of six glass-ionomer composite resin hybrid materials compared with a glass-ionomer cement and a composite resin. Standardized class 5 dentin cavities were prepared on root surfaces of 240 extracted human teeth that were randomly assigned to eight groups and restored using the following restorative systems: (I) Vitremer, (II) Compoglass, (III) Photac-Fil Aplicap, (IV) Variglass, (V) Dyract, (VI) Fuji II LC, (VII) Ketac-Fil Aplicap, and (VIII) Z100. The teeth were thermocycled, placed in a 2% methylene blue solution, and sectioned with diamond disks. Dye penetration was scored on a scale of 0-3. Results showed no significant differences among groups VIII, IV, I, V, VI, III, and II. There were also no significant differences among groups VI, III, II, and VII.

Volumetric microleakage assessment of glass-ionomer-resin composite hybrid materials.

OBJECTIVE: This study was intended to quantify the marginal leakage of three glass-ionomer-resin composite hybrid materials and compare it with the leakage exhibited by a glass-ionomer cement and a bonded resin composite system. METHOD AND MATERIALS: Standardized Class V cavities were prepared on root surfaces of 105 extracted human teeth, randomly assigned to five groups of 21 each, and restored with either Ketac-Fil Aplicap, Z100/Scotchbond Multi-Purpose Plus, Vitremer, Photac-Fil Aplicap, or Dyract. The teeth were thermally stressed for 500 cycles and stained with methylene blue. The microleakage was quantified spectrophotometrically, and the data were statistically analyzed with Friedman's test. RESULTS: There were no significant differences in microleakage among the five groups. Restorations of all tested materials showed some marginal leakage in Class V cavities. CONCLUSION: The microleakage performance of glass-ionomer-resin composite hybrid materials was similar to those of a conventional glass-ionomer and a bonded resin composite system.