Assessment of Microleakage in Class II Cavities having Gingival Wall in Cementum using Three Different Posterior Composites.

BACKGROUND: Dental composites are one of the most desired restorative materials today. Composite materials can be bonded successfully to human tooth enamel; however, developing the same degree of adhesion to dentin or cementum is a more challenging task. Polymerization contraction stress of dental composites is often associated with marginal and interfacial failures of bonded restorations. The magnitude of stress depends on composite composition and its ability to flow before gelation, which is related to the cavity configuration and curing characteristics of the composite. MATERIALS AND METHODS: This study was carried out on 24 extracted human molars and divided into three groups. Class II (slot) cavities were prepared on the mesial and distal surfaces of the teeth with the gingival wall in dentin/cementum, and the microleakage was observed. After preparation the teeth were randomly assigned into three groups of eight specimens each. The cavities were restored with: Group 1: Packable composite (Surefil, Dentsply); Group 2: Hybrid composite (Filtek Z250, 3M Dental Products); Group 3: Nanocomposite (Filtek Z350, 3M Dental Products). Sixteen samples of each group were subjected to 500 cycles of thermocycling between 5°C and 55°C. All the teeth were immersed in methylene blue for 8 h and then left in tap water for 12 h. The teeth were sectioned mesiodistally with a diamond disc, and examined under a stereomicroscope. RESULTS: The analysis indicated that packable composite showed more microleakage than all the other groups. Hybrid composite showed less microleakage than packable composite, but more leakage than nanocomposite. CONCLUSION: All composites under the study exhibited a certain amount of microleakage in the dentin/cementum margin. Packable composite showed the most microleakage and nanocomposite showed least microleakage. Since these results were obtained in vitro, long-term clinical trials are needed to fully understand the performance of these materials.

Electrosurgery in aesthetic and restorative dentistry: A literature review and case reports.

Electrosurgery has been used in dentistry for more than half a century. There is abundant literature on electrosurgery dating back more than a century. During the past three decades, a substantial increase in minimally invasive surgery and microvascular surgery prompted greater use of electrosurgery. Although this surge in utilization has resulted in new applications, equipment features, problems and solutions, the use of electrosurgery in the field of restorative dentistry has remained relatively unchanged. The presence of conflicting and sometimes confusing information on electrosurgical wound healing in the dental literature is the most likely reason. This article briefly explains the literature review of electrosurgery and clinical application of electrosurgery in aesthetic and restorative dentistry.

The influence of different composite placement techniques on microleakage in preparations with high C- factor: An in vitro study.

OBJECTIVE: This study evaluated the marginal leakage around class-I cavity preparations restored with Nanofilled composite (Filtek Z-350 A2 shade, 3M ESPE, USA) and a self-etch adhesive (Xeno III, DENTSPLY/Caulk) using different composite placement techniques. MATERIALS AND METHODS: Standardized class-I cavities were prepared on 36 caries-free, extracted human premolars and were randomly assigned to three groups: (1) Horizontal incremental curing was done; each increment of thickness 1.5 mm was cured one after the other using curing unit (T-LED, Elca Technology, Italy). (2) Concave surface was obtained with a ball burnisher on the first increment and cured for 20 seconds; subsequently, the next increment was placed and similarly cured. (3) Cavities were filled with resin, short of the occlusal surface; two cuts (mesiodistal and buccolingual) were made through the condensed resin and cured for 20 seconds, followed by addition of resin in the gaps created by the cuts and additional curing for 20 seconds. The specimens were stored in distilled water for three months and then subjected to thermocycling, followed by immersion in 0.5% methylene blue dye for 24 hours. The teeth were sectioned longitudinally and evaluated for microleakage under stereomicroscope, and the scores obtained were analysed with Fisher Exact test and Kruskal-Wallis nonparametric test. RESULTS: There was no statistically significant difference among three groups. CONCLUSION: None of the techniques was capable of eliminating the microleakage in preparations with a high C-factor.