Comparative microleakage outcomes of different techniques used for creating the occlusal anatomy in occlusal direct restorations using the dental operating microscope.

OBJECTIVES: Microleakage in direct dental restorations is a primary causal factor in the restoration's failure. The aim of this study was to evaluate whether the technique for occlusal layering of the composite resin (the use of brush adaptation, the use of magnification, cusp build-up, stamp technique) has any effect on microleakage of direct restorations in occlusal cavities. MATERIALS AND METHODS: One hundred extracted human molars were restored using five restoration techniques (Packable Bulk technique, Occlusal Stamp technique, Successive Cusp Build-up technique, Successive Cusp Build-up technique + Brush adaptation, Successive Cusp Build-up technique + brush adaptation + Dental Operative Microscope magnification). The teeth were subjected to thermal aging for 800 cycles at 5°C and 55°C, infiltrated with basic fuchsin dye for 24 h, and then sectioned buccolingually in the middle of the crown. Infiltration was measured in four areas of the tooth section by five different observers and then given a score from 1 to 3, proportional to infiltration depth. RESULTS: The lowest mean scores for infiltration (meaning less infiltration observed) were present in Group A (1.41 ± 0.878) and Group C (1.46 ± 0.679), while Group D showed the highest infiltration scores (1.75 ± 0.853). When comparing the groups for differences, no statistically significant difference in infiltration was found between any technique p < .586. CONCLUSION: The techniques examined for placing the occlusal layer of composite in direct restorations do not differ significantly in terms of marginal infiltration, although a slight improvement was found when using the bulk technique and the successive cusp build-up.

The quality of single cone and laterally compacted gutta-percha fillings in small and curved root canals as evidenced by bidirectional radiographs and fluid transport measurements.

OBJECTIVE: The aim of this study was to examine the quality of root fillings in small and curved root canals using bidirectional radiographs and fluid transport (FT) measurements. STUDY DESIGN: Root canals in eighty 38 degrees -curved mesial roots of mandibular molars were prepared using a balanced force technique. Samples were divided into 4 groups of 20 each and obturated by either the cold lateral compaction (LC) or the single cone (SC) technique, using either epoxy resin-based or zinc oxide-eugenol sealers. Bidirectional (buccolingual and mesiodistal) radiographs were acquired from each root. The voids along the root filling were assessed. The FT along the root filling was measured using an FT monitoring device. The differences between the groups regarding FT and the bidirectional radiographic score were analyzed by means of a Kruskal-Wallis test. The correlation between the FT values and the radiographic scores were analyzed using a Spearman test. RESULTS: Three groups of LC or SC fillings containing epoxy resin-based sealers exhibited similar radiographic scores and FT values (P > .05). The group of SC fillings that contained zinc oxide-eugenol sealer had worse radiographic scores than the other groups (P = .047). The bidirectional radiographic scores and the FT values for the 80 filled roots were strongly correlated (r(2) = 0.519; P = .00001). CONCLUSION: Root fillings of similar quality were confirmed in small and curved root canals filled using either a single cone or laterally compacted gutta-percha and epoxy resin-based sealers.