Effect of Cavity Configuration (C Factor) on the Marginal Adaptation of Low-Shrinking Composite: A Comparative Ex Vivo Study

Abstract

Aim. To investigate the effect of C factor on marginal adaptation of low-shrinking composite (Silorane).The null hypothesis was that the marginal adaptation of “Silorane” is not affected by the cavity configuration. Materials and Methods. A Silorane based and a methacrylate based composites, with their corresponding self-etch adhesive systems “Filtek Silorane/Silorane Adhesive Bond System and Filtek Z250/Prompt L-Pop” respectively were used. Standardized cavities were prepared on the buccal surfaces of 100 maxillary premolars. Teeth were grouped into 5 groups (n = 20), for the 5 C factors. Restored teeth were subjected to thermocycling. Microleakage testing was done and linear dye penetration was assessed using a stereomicroscope. Statistical analysis was done using the Student's t-test. Results. For the methacrylate based systems' overall leakage score was significantly higher than the Silorane-based one (P = 0.034). For the methacrylate-based, leakage was found in all tested teeth groups except group 1 (C factor 1/5). For the Silorane, One-way ANOVA revealed a statistically significant increase in dye penetration in the 5th group (P = 0.010). Conclusions. The null hypothesis was rejected. The Silorane-based resin although it resulted in a statistically significant good marginal adaptation, it showed tendency toward a high leakage score with C-factor of 5.

Microleakage of Class I and II Composite Resin Restorations Using a Sonic-resin Placement System

“…13,17 The preparation C-factor can influence the magnitude of stress on posterior composites and has been defined as the ratio of the bonded to the unbonded surfaces of a cavity preparation. 12,14 A restoration with high C-factor would indicate a greater potential for bond interruption due to the forces imposed from polymerization shrinkage, with subsequent formation of marginal gaps and/or voids and, consequently, microleakage. 12,14 Class I preparations have the highest C-factors as a result of the number of bondable surfaces; therefore, they have the greatest potential for the detrimental effects of polymerization.…”

“…12,14 A restoration with high C-factor would indicate a greater potential for bond interruption due to the forces imposed from polymerization shrinkage, with subsequent formation of marginal gaps and/or voids and, consequently, microleakage. 12,14 Class I preparations have the highest C-factors as a result of the number of bondable surfaces; therefore, they have the greatest potential for the detrimental effects of polymerization. Class II, III, IV, and V preparations have lower C-factors because of the ratio of bonded to unbonded surfaces and, therefore, predispose the restoration to a lower risk for possible clinical sequelae.…”

“…Clinical variables include material manipulation and insertion techniques, isolation constraints (usage of dental rubber dam), and adequate knowledge of adhesive and composite resin science and applicable technique. [9][10][11][12][13][14][15][16] Composite resin, used as a posterior restorative, is significantly influenced by polymerization shrinkage with amounts ranging from 1.5% to 5%. 11 Shrinkage causes debonding of the material from tooth structure, precipitating clinical and radiographic sequelae including marginal staining and micro-gap formation (approximately 10 to 20 lm).…”

Sifat fisik hidroksiapatit sintesis kalsit sebagai bahan pengisi pada sealer saluran akar resin epoxy (Physical properties of calcite synthesized hydroxyapatite as the filler of epoxy-resin-based root canal sealer)

“…Pada kondisi lembab monomer yang tidak terpolimerisasi akan lebih cepat terlepas dari resin polimer sehingga mempengaruhi sifat fisik sealer yaitu mengurangi adaptasi sealer dengan dinding saluran akar. 26,27 Hasil penelitian ini menunjukkan bahwa pada batasan tertentu penambahan HA sintesis kalsit sebagai bahan pengisi (filler) dapat meningkatkan sifat fisis bahan yang berarti meningkatkan kualitas bahan, sebaliknya pada batasan tertentu penambahan bahan pengisi HA justru menurunkan kualitas fisik bahan. Penambahan bahan pengisi juga dipercaya akan mengurangi pengerutan polimerisasi sealer resin ini.…”

Polymerization Shrinkage and Spherical Glass Mega Fillers: Effects on Cuspal Deflection

“…If the thickness of the residual dental tissue is thin, it may also occur of the enamel fracture (enamel crack) when this latter is not sufficiently supported by the dentin (11). This phenomenon, together with the flow that the composite undergoes, during the setting reaction, at the level of the free surface of the restoration, which is not subject to adhesion, limits the negative effects of stress but does not cancel them completely (12,13). The ability of the composite to develop stress during its polymerization does depend greatly on the extent of the free surface compared with the adherent one and it's therefore strictly dependent on the cavity configuration.…”