Gül Özgünaltay

A morphological and micro-tensile bond strength evaluation of a single-bottle adhesive to caries-affected human dentine after four different caries removal techniques

OBJECTIVES This study evaluated the influence of different caries removal techniques (conventional bur; chemomechanical removal/Carisolv()-MediTeam; a sonic preparation system/SonicsysMicro-Kavo and air abrasion/PrepStar-Danville Engineering) on microtensile bond strength to caries-affected human dentine. METHODS Occlusal surfaces of extracted human permanent third molars with coronal dentine caries extending approximately halfway through the dentine was ground perpendicular to the long axis of the tooth to expose a flat surface of normal dentine surrounding the carious lesion with laser fluorescence values of approximately 30 (DIAGNODent), KaVo). Carious lesions were excavated with one of the four techniques until laser fluorescence values decreased to 15 in the center of the lesions. An ethanol-based dentine adhesive (Single Bond, 3M) was used to bond composite resin (P60, 3M) to the substrate. Vertical slices (n=11/group), approximately 0.8 mm thick were made through the caries-affected portions of each tooth, perpendicular to the bonding surface. Specimens were subjected to tensile stress at a crosshead speed of 1 mm/min. Data were analyzed by Kruskal-Wallis test. SEM investigation was performed for the qualitative evaluation of resin-dentine hybridization. RESULTS The microtensile bond strengths were as follows (mean+/-SD in MPa): 6.4+/-5.3 (bur), 8.4+/-3.3 (Carisolv), 8.5+/-5.9 (Sonicsys Micro), and 8.8+/-8.8 (air abrasion). Statistical analysis did not show significant differences between any of the treatment modalities (p=0.160). Tensile fracture was cohesive within caries-affected dentine in all specimens. CONCLUSIONS The four different caries removal techniques used within this study did not influence the bond strength of the tested dentine adhesive to caries-affected human dentine.

Clinical evaluation of different adhesives used in the restoration of non-carious cervical lesions: 24-month results.

BACKGROUND The aim of this study was to compare after 24 months the clinical performance of cervical restorations placed with the use of an etch-and-rinse and an all-in-one adhesive. METHODS Twenty-four patients with at least one pair of non-carious cervical lesions participated in this study. One hundred and twenty-three cervical lesions were restored (62 etch-and-rinse adhesive, Solobond M; 61 all-in-one adhesive, Futurabond NR). A nanohybrid resin composite, Grandio, was used as the restorative material. Restorations were evaluated according to modified USPHS criteria by two independent examiners. The survival rates of the restorations were calculated by the Kaplan-Meier estimator and log-rank test. The restorations in each category were compared using the Pearson chi-square test, while the performance of restorations at the baseline and at each recall time was evaluated by McNemars test (p < 0.05). RESULTS The recall rate of patients was 100%. The retention rates were 82% and 75% at 6 months and 77% and 62% at 12 months for Solobond M and Futurabond NR, respectively. At the 24-month recall, the retention rate was 69% for Solobond M and 49% for Futurabond NR, and this difference was statistically significant (p < 0.05). No statistically significant difference was found for colour match, marginal staining, or marginal adaptation between the adhesives (p > 0.05). None of the restorations had secondary caries, loss of anatomical form, or surface texture changes. CONCLUSIONS Cervical restorations placed with an etch-and-rinse adhesive showed higher retention than an all-in-one adhesive.

Effects of preparation designs and adhesive systems on retention of class II amalgam restorations

PURPOSE This study evaluated the effects of three preparation designs and the influence of an adhesive system in Class II amalgam restorations when a load was applied directly to the marginal ridge. MATERIAL AND METHODS Seventy-two sound caries-free maxillary molars were divided into 6 groups of 12 teeth. In groups 1 and 4, the preparation had an extension through the occlusal groove, whereas the other four groups used a proximal slot (box-only) preparation. Groups 2 and 5 had facial and lingual retention grooves that extended from the gingival floor to the occlusal surface, and groups 3 and 6 had slots without grooves. Teeth in groups 1, 2, and 3 were restored with amalgam and groups 4, 5, and 6 were restored with resin bonded amalgam. The marginal ridges of the restorations were loaded at an angle of 13.5 degrees to the long axis of the tooth in an Instron testing machine until failure. RESULTS Analysis of mean failure loads indicated that proximal slot preparations with retention grooves or occlusal extensions were statistically equivalent but significantly greater than proximal slots without grooves. The addition of an adhesive system improved fracture values for all three types of preparations. CONCLUSIONS When proximal caries was diagnosed and no occlusal caries was evident, a proximal slot amalgam restoration combined with retention grooves and an adhesive system was the appropriate choice.

Comparison of the Er,Cr:YSGG laser with a chemical vapour deposition bur and conventional techniques for cavity preparation: a microleakage study

The aim of this study was to compare the effects of the Er,Cr:YSGG laser using chemical vapour deposition (CVD) bur cavity preparation with conventional preparation methods including a diamond bur and a carbide bur on the microleakage with two different adhesive systems. A total of 40 extracted human premolars were randomly assigned to four experimental groups according to the cavity preparation technique: group I diamond bur (Diatech); group II carbide bur (Diatech); group III Er,Cr:YSGG laser (Biolase Millennium II); and group IV CVD bur (CVDentUS). Using the different preparation techniques, Class V standardized preparations were performed on the buccal and lingual surfaces with gingival margins on the dentin and occlusal margins on the enamel. Each preparation group was randomly assigned to two subgroups (five teeth, ten preparations) according to the type of adhesive: an etch-and-rinse adhesive (Adper Single Bond), and a single-step self-etch adhesive (AdheSE One). All preparations were restored with a nanohybrid composite resin in a single increment. Following thermocycling (×500; 5–55°C), the teeth were immersed in basic fuchsin and sectioned in the orovestibular direction. Dye penetration was evaluated under a light microscope by two blinded examiners. Data were statistically analysed with the Kruskal-Wallis and Wilcoxon tests (p<0.05). There were no statistically significant differences between the preparation techniques with either of the two adhesive systems (p>0.05). Comparing the enamel and dentin leakage scores within each group, no statistically significant differences were found (p>0.05). The Er,Cr:YSGG laser cavity preparation did not differ from preparation with CVD, diamond or carbide bur in terms of microleakage with the different adhesive systems.

Effect of operator variability on microleakage with different adhesive systems

Objective: The objective of this study was to evaluate the effect of operator variability on microleakage with different adhesive systems. Materials and Methods: A total of 180 standardized Class V cavities were prepared on facial and lingual of 90 extracted human premolar teeth and randomly assigned to five groups according to the adhesive systems used (n = 36): Prime and Bond NT (PB), Single Bond (SB), Futura Bond NR, Xeno III (XE) and Adper Prompt-L-Pop (LP). The adhesive groups were then further subdivided into three operator groups according to level of clinical experience (n = 12): An undergraduate student, a research assistant and a faculty member. All cavities were restored with same composite resin. The restored teeth were thermocycled (500 cycles, 5-55°C) then immersed in 0.5% basic fuchsin and measured for leakage under a stereomicroscope. Statistical analyses were performed with the Kruskal-Wallis and Mann-Whitney U tests. Results: Significant inter-operator variation was found in the enamel margins in the XE group with significantly higher microleakage when used by the undergraduate student (P < 0.05). Although no significant differences in microleakage were found between adhesive systems for the research assistant and faculty member (P > 0.05), significant differences were observed between PB and LP, PB and XE, SB and LP and SB and XE in the enamel margins for the undergraduate student (P < 0.05). Conclusion: Microleakage of adhesive systems is more dependent on interactions between the operator and adhesive material than on the choice of adhesive material.

Antimicrobial Effect of Ozone on Cariogenic Microorganisms In Vitro

The aim of this study was to examine the antibacterial effect of ozone on cariogenic microorganisms. Streptococcus salivarius, Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei and Actinomyces viscosus were used to test the antimicrobial activity of ozone. The microorganisms were exposed to power levels 2, 3, or 4 of an ozone device for 20, 40, 60, or 120 s. CFU numbers of bacteria were counted after the ozone application; as a result, the number of bacterial cells was decreased. The bacterial cells were also evaluated with a fluorescence microscope. This analysis revealed that some bacterial cells were killed instantaneously in ozone. The electron microscopic analysis showed no difference in surface morphology between bacteria to which ozone had been applied and those to which it had not.

Bond strengths of bulk-fill resin composite repairs: effect of different surface treatment protocols in vitro

Abstract To evaluate the effect of different surface treatment protocols on the microtensile bond strength (μTBS) of bulk-fill resin composite repairs. Thirty-five bulk-fill resin composite samples (Filtek Bulk Fill) were prepared (5 × 5 × 5 mm) and aged by thermocycling (X5000). Samples were randomly divided into five groups (n = 7): a control (no treatment) and four surface treatment groups (Single Bond Universal [SBU]; phosphoric acid (37%) + SBU; Er,Cr:YSGG laser + SBU; aluminum oxide sandblasting + SBU). Filtek Ultimate Universal composite was used as a repair material. After storage for 24 h in distilled water (37 °C), sticks were obtained and subjected to a μTBS test. The data (MPa) were analyzed by one-way ANOVA with a post hoc test (α = 0.05). Failure mode was evaluated using a light microscope (10×). There were significant differences between the groups (p < 0.05). The lowest bond strength values were obtained in the control group (p < 0.05). No significant difference was observed between Group II (universal adhesive) and Group III (acid etch + universal adhesive) (p > 0.05). The bond strength of Group II was significantly lower than that of the other surface treatment groups (p < 0.05). While Group III showed significantly lower values than those of the laser treatment group (Group IV), similar values were obtained with Al2O3 sandblasting group (Group V). The highest repair bond strength was obtained in Group IV (p < 0.05) which was not significantly different from the Al2O3 sandblasting group (p > 0.05). The predominant failure mode was adhesive. Treatment of aged bulk-fill resin composite surfaces with laser and Al2O3 sandblasting provided higher repair bond strength values.