Evaluation of cervical marginal and internal adaptation using newer bulk fill composites: An in vitro study

Abstract

Objective:To evaluate the cervical marginal and internal adaptation of posterior bulk fill resin composites of different viscosities, before and after thermo-cycling (TMC).Materials and Methods:Eighty box-only class II cavities were prepared in 40 extracted human premolars with the distal proximal box beneath the enamel-cementum junction (CEJ). The teeth in the experimental groups were restored with bulk fill resin composite restorations (Gr. I- Sonic Fill, Gr. II- SDR, Gr. III- Tetric N Ceram Bulk Fill or a conventional composite designed for 2-mm increments (Gr. IV- Tetric N Flow along with Tetric N Ceram). Before and after thermal cycling, the gap-free marginal length was analyzed using SEM of epoxy resin replicas. After thermal cycling, specimens were cut longitudinally in order to investigate internal dentine adaptation by epoxy replicas under SEM (500 × magnification).Results:Statistical analysis was performed using the ANOVA and Tukey Post Hoc tests (P < 0.05). In enamel, high percentages of gap-free margins were initially identified for all the groups, which declined after thermal cycling. However, no significant differences were identified among any of the groups (P > 0.05). In dentine, bulk fill groups performed at par with the incremental placement; for both marginal and internal adaptation (P < 0.05), for all materials except Tetric N Ceram Bulk Fill.Conclusions:Viscosity of the bulk fill restorative material influenced the proportion of gap-free marginal interface and the internal adaptation in dentin.

One‐year clinical evaluation of different types of bulk‐fill composites

“…The recent introduction of bulk‐fill restorative materials has reignited the debate of “bulk‐ versus incrementally‐placed” composites. Some critics of the bulk‐fill approach argue that the effect of shrinkage stress might be more pronounced when bulk‐fill techniques are employed, as the entire mass polymerizes at one time as opposed to small increments . An ideal bulk‐fill composite would be one that could be placed into a preparation that has a high C‐factor design and still exhibits very little polymerization shrinkage stress while maintaining a high degree of cure throughout …”

Influence of Composite Insertion Techniques (Bulk-fill and Incremental Nanofilled Composites) on Adaptability to the Pulpal Floor and Interfacial Gap Formation

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Twenty freshly extracted human maxillary premolars extracted for orthodontic reasons were selected for the study. Teeth with developmental defects, occlusal wear facets, and microcracks were categorized as exclusion criteria.…”

Is there correlation between polymerization shrinkage, gap formation, and void in bulk fill composites? A μCT study

“…Polymerization shrinkage and/or gap formation has been evaluated in the literature by means of different destructive tests, 19,20,21,22,23 hindering a more detailed analysis of the resin composite body before and after polymerization. Computerized microtomography (μCT) has been used to quantify and evaluate polymerization shrinkage, 22,23 in order to examine the tooth/restoration interface, as well as other changes in the material.…”