Polymerization shrinkage of different types of composite resins and microleakage with and without liner in class II cavities

The Effect of Simulated Chewing on the Surface Roughness of Direct and Indirect Resin-Composites Opposed by Zirconia: An In Vitro Study

Purpose

To assess the surface roughness of two different light-cured resin-composites when opposed by monolithic zirconia after simulated mastication.

Materials and Methods

Materials included a direct restorative nanohybrid (n = 10) and an indirect microhybrid (n = 10) resin-composite (Tetric EvoCeram and Sinfony, respectively). The antagonist material was 3 mol% yttria-stabilized tetragonal zirconia polycrystalline ceramic. Each material was subjected to in vitro chewing against zirconia using a chewing simulator for 250,000 cycles. A 3D profilometer was used to assess the surface roughness parameters of each resin-composite before and after the simulated chewing. Independent t-test and paired sample t-test were performed to compare roughness values for both materials and to compare baseline and after chewing simulation values (p = 0.05).

Results

Sinfony showed significantly greater roughness values compared to Tetric EvoCeram (p ≤ 0.025) before and after simulated chewing, except for Sa and Sv parameters after simulated chewing where the difference between the two materials was insignificant (p = 0.06 and 0.89, respectively). Surface roughness increased for both materials after simulated chewing compared to baseline values, but the difference was insignificant (p ≥ 0.065). However, Sa (p = 0.04) and Sv (p = 0.012) for Tetric EvoCeram were significantly higher after compared to before chewing simulation.

Conclusion

Tetric EvoCeram had a smoother surface than Sinfony before and after simulated chewing. Surface roughness for both materials was higher after simulated chewing compared to baseline values which represent surface damage that was significant for Tetric EvoCeram while Sinfony showed better resistance.

Evaluation of the Sealing Ability of Direct versus Direct-Indirect Veneer Techniques: An In Vitro Study

BACKGROUNDS

Marginal discoloration, microleakage, wear, and marginal fractures are all prevalent problems with composite veneers, and this scenario leads the esthetic outcome to deteriorate with time, resulting in patient discontent. Aim of the Study. The study's goal was to determine the marginal sealing ability of composite laminate veneers when employing two types of veneer techniques: direct and direct-indirect veneers, as well as two types of composite resin: nanohybrid and microfilled composite resin restorations, using dye penetration method.

MATERIALS AND METHODS

In this study, forty extracted human teeth were utilized. Following a standardized veneer preparation on the labial surface of the teeth, they were separated into two groups of 20 teeth each, using the following composite application techniques: group A: direct veneers and group B: direct-indirect veneers. Following that, each major group was separated into two subgroups of ten teeth each, based on the type of composite employed: subgroup 1 used nanohybrid composite resin, while subgroup 2 used microfilled composite resin. All of the samples were kept in distilled water, thermocycled, and soaked in 2% basic fuchsine dye. These specimens were sectioned and examined under a stereomicroscope for dye penetration at the gingival margin. The data was analyzed using independent T-tests using SPSS 22.

RESULT

Using direct-indirect veneer technique with nanohybrid composite resin material resulted in the most negligible dye penetration at the gingival margin, while using direct veneer technique with microfilled composite resin material resulted in the maximum dye penetration. For both composite materials, gingival microleakage was lower when using the direct-indirect veneer technique than when using the direct technique, and the difference was statistically significant (P < 0.05). In both techniques, gingival microleakage was lower with nanohybrid composite than with microfilled composite, and the difference was statistically highly significant (P = 0.001).

CONCLUSION

The sealing ability of the gingival margin of tooth/composite interface is better when applying direct-indirect veneer technique with nanohybrid composite resin than that of direct veneer technique with microfilled composite resin material.

The Effect of Scuba Diving on Microleakage of a Class II Composite Restoration: An In-Vitro Study

Persistent pressure change is a common phenomenon within scuba diving with various medical and dental sign side effects. This study evaluates the effect of simulated pressure change due to scuba diving on the microleakage of class II composite restoration. In our methodology, a total number of 150 intact bicuspids are divided into two main groups (A and B), and prepared for a class II composite restoration. The samples of each main group are divided into five subgroups to be prepared with different liners. Then samples are restored with the same resin composite material. The teeth in group A are thermocycled under the normal atmospheric pressure, while group B are thermocycled under simulated scuba diving conditions. The gingival microleakage is assessed based on dye penetration. The group B teeth show a significantly higher microleakage score than their equivalents in group A (p < 0.05). The subgroups without a liner have a higher microleakage score than the other subgroups (p < 0.05). The flowable composite shows the leased leakage scores followed by Nano ionomer, Resin Modified Glass Iononomer, GIOMER, and linerless groups (p < 0.05). Scuba diving could increase the risk of microleakage development beneath class II, a composite restoration.

24 hour polymerization shrinkage of resin composite core materials

PURPOSE

The study's purpose was to evaluate the 24-hour polymerization shrinkage of resin composite core materials.

MATERIAL AND METHODS

Eleven resin composite core material samples (n = 12) were evaluated using a non-contact imaging device with measurements obtained over 24 h. Shrinkage values were determined corresponding to proposed times involved with CAD/CAM same-day treatment and at 24 h. Shrinkage data was statistically compared using Friedman/Dunn's test for intragroup analysis and Kruskal Wallis/Dunn's test for intergroup analysis, all at a 95% level of confidence (α = 0.05).

RESULTS

Mean results identified a wide volumetric shrinkage range with considerable similarity overlap. Inconsistent shrinkage behavior was evident and all materials reached maximum values before 24 h. No significant difference was observed during proposed digital same day all ceramic crown procedures, but some differences were noted at 24 h.

CONCLUSIONS

Under this study's conditions results were material specific, at times inconsistent, with wide variation. Shrinkage consistently increased for all products and it is not known if the continued shrinkage magnitude may compromise the stability and fit of all-ceramic crowns at 24 h.

Evaluating the Failure of Resin-based Materials on the Proximal Cervical Dentin

Background:

Resin-based materials are the popular restorative material in dentistry. The majority of these materials are light cured with a major disadvantage: marginal leakage.

Objective:

To evaluate the gap width of different resin-based materials at the cervical dentin when achieved mechanical force.

Methods:

Class II cavities were prepared on extracted premolar teeth with the gingival margin 1 mm below the Cementoenamel Junction (CEJ). In the first three experimental groups, three different lining materials (flowable resin composite, bulk-fill flowable resin composite, and resin-modified glass ionomer cement) were placed at the cervical dentin with a thickness of 1 mm. The rest of the cavities were restored with conventional resin composite. The other two groups were restored with conventional resin composite (control) or high viscosity bulk-fill resin composite, respectively. All groups were thermocycled and underwent vacuum pressure 2.6 KPa for 30 min in a Scanning Electron Microscope (SEM).

Results:

There was no gap formation at the cervical dentin on the external surface when restored with high-viscosity bulk fill resin composite. Almost all gaps occurred at the interface between restorative materials and the hybrid layer. The flowable bulk fill resin composite showed a significantly smaller gap width on both the external and internal surfaces compared to the other groups (p< 0.05). The resin-modified glass ionomer cement showed the largest gaps in the cervical dentin (p < 0.05).

Conclusion:

The different types of resin-based materials demonstrated a different failure of gap width under mechanical force. It clearly occurred at the restorative material-hybrid layer interface.

Application of Scanning Electron Microscopy in the observation of dentin-adhesive interface

The objective of this study was observation of the adhesive interface on original tooth samples, as well as their epoxy replicas, under SEM. A light-cure flowable composite was incrementally placed and light-polymerized in previously prepared cylindrical dentinal cavities on the buccal surfaces of extracted human third molars. After finishing procedures, impressions of the composite/dentin margin were made using polyvinylsiloxane in order to obtain accurate epoxy replicas for SEM analysis. Ultrastructural morphology of the adhesive surface was observed at high magnifications (≥1,000×) on original tooth samples, which were previously prepared to expose the part of the dentin surface, which participates in the formation of adhesive bond. SEM micrographs showed that marginal adaptation was mostly of acceptable quality. In some of the SEM micrographs of original tooth samples, marginal gap formation, and resin tag breakdown were noted, which were ascribed to polymerization shrinkage. Profound understanding of ultrastructural morphology is necessary for achieving more predictable and durable margin between composite restorations and surrounding tooth structures, and SEM analysis can serve that purpose.

Microleakage of Aesthetic Restorations Following Functional Simulation and Immersion in Saudi-Traditional Mouth Rinses

AIM:

The study is aimed to assess the effect of 3 Saudi-traditional types of mouth rinses (Karadah, Myrrh, salted water) on the microleakage of composite and glass-ionomer restorations subjected to thermal cycling and cyclic loading.

MATERIAL AND METHODS:

Class V cavities in both buccal and lingual surfaces of eighty extracted premolars were restored with both nano-filled composite and glass-ionomer restoratives. Half the number of restored teeth (group 1, n = 40) were subjected to further thermal cycling and cyclic loading to mimic the in-service functional stresses. The rest of the teeth were left as control with no functional simulation (group 2, n = 40). Teeth of each group were then stored wet for one month in 4 subgroups (n = 10) according to the storage media (distilled water, salted water, Myrrh and Karadah extracts). Following wet ageing, all teeth were immersed in methylene blue solution for 24 hrs, followed by sectioning in Bucco-lingual direction. The microleakage was inspected using stereomicroscope and rated from 0-4 according to its penetration depth. The collected non-parametrical data was then analysed statistically using Kruskal-Wallis One-way ANOVA at α = 0.05.

RESULTS:

There was no statistically significant difference observed in microleakage between specimens treated with any of the mouthwashes for both glass ionomer and composite restorations in the presence and absence of thermal cycling and cyclic loading (p = 0.889).

CONCLUSION:

Given the results of the present study, the Saudi-traditional types of mouth rinses are not contributory to microleakage in aesthetic-based composite and glass-ionomer restorations.

Experimental synthesis of size-controlled TiO2 nanofillers and their possible use as composites in restorative dentistry

The aim of this work was to obtain an efficient protocol with a green, fast and facile way to synthesize TiO2 NPs and its application as fillers for enhancement of desired dental properties of light curing dental composites. A comparative study comprised the fabrication of light curing restorative composite materials with incorporating different fillers with varying wt%, varying resin material composition, to determine optimal dental restoration by focusing on the physical properties of dental materials. It was observed that the as-prepared green synthesized TiO2 nanohybrid particles contributed to the improvement in physical properties, thus promoting the green and rapid synthesis of nanohybrid fillers. In addition, mechanical values for experimental cured resin materials with bare and surface modified fillers were obtained. The experimental light curing nanocomposites with 5 wt% (wt%) nanohybrid surface modified filler particles with BisGMA (60 wt%), TEGDMA (20 wt%) and UDMA (20 wt%) resin composition provided increased physical strength and durability with higher compressive stress 195.56 MPa and flexural stress 83.30 MPa. Furthermore, the dental property, such as polymerization shrinkage (PS) obtained from volumetric method was decreased up to 3.4% by the addition of nano-hybrid fillers. In addition to this, the biocompatible and antimicrobial nature of TiO2 and its aesthetics properties such as tooth-like color makes TiO2 favorable to use as fillers. This study presents a green and facile method for the synthesis of TiO2 nanohybrid particles that can be successfully used as fillers in an experimental light curing resin matrix for enhancing its dental properties. This describes the potential of the green synthesized TiO2 nanohybrid particles to use as fillers in restorative dentistry.

Internal adaptation of composite restorations with or without an intermediate layer: Effect of polymerization shrinkage parameters of the layer material

OBJECTIVES

The purpose of this study was to compare the internal adaptation of resin composite restorations in Class I cavities with or without an intermediate layer, and to identify the relationships between the internal adaptation and the polymerization shrinkage parameters of the layer material.

METHODS

Class I cavities prepared in human third molars were treated with a one-step self-etch adhesive (G-Premio Bond, GC). In the control group, Tetric-EvoCeram Bulk-Fill (TBF, Ivoclar Vivadent) was placed using the bulk-fill technique and then light-cured. In the experimental groups, six different layer materials (three flowable resin composites, two bulk-fill resin composites, and a resin-modified glass-ionomer) were applied to a 1.5-mm thickness and light-cured, which was followed by TBF filling. After thermo-cycling, internal adaptation was measured using swept-source optical coherence tomography (SS-OCT) imaging and compared in terms of high brightness percentage (HB%) to represent the microgap. Shrinkage strain (SS), flexural modulus (FM), and polymerization shrinkage stress of the intermediate layer-resin composite complex (PS) were measured for each material. The relationships among HB%, SS, FM, and PS were evaluated statistically.

RESULTS

Groups with an intermediate layer showed lower HB% than the control group. The HB% correlated with PS (Pearson's correlation: R² = 0.883, p < 0.05), and the PS correlated with the product of SS and FM.

CONCLUSION

Internal adaptation depended on the polymerization shrinkage stress of the intermediate layer-resin composite complex.

CLINICAL SIGNIFICANCE

Bulk-fill resin composite, which can show low polymerization shrinkage stress, may be used as an intermediate layer for better internal adaptation.

Influence of Shrinkage and Viscosity of Flowable Composite Liners on Cervical Microleakage of Class II Restorations: A Micro-CT Analysis

This study determined the influence of shrinkage and viscosity of flowable composite liners on the cervical microleakage of Class II restorations using micro-CT. Seven composites of varying viscosities were selected and included five giomers (Shofu Beautifil II [BF], Flow Plus F00 and F03 [F00 and F03], Flow F02 and F10 [F02 and F10]) and 2 nano-filled composites (3M-ESPE Filtek Z350 [Z350] and Filtek Z350 Flowable [Z350F]). Polymerization shrinkage (n=7) was assessed with the Acuvol volumetric shrinkage analyzer while complex viscosity was determined with the advanced rheometric expansion system at 25°C. Standardized Class II restorations incorporating 1-mm horizontal layers of different flowable liners and 3-mm oblique layers of BF or Z350 were subjected to a silver nitrate test for 24 hours and examined using micro-CT. Microleakage was determined at 0.1-mm intervals from the buccal to lingual surfaces providing 30 sites per specimen and scored accordingly. Statistical analysis was performed with the one-way ANOVA, Kruskal-Wallis test, and Spearman's rho correlation at a significance level of p<0.05. Mean volumetric shrinkage ranged from 5.33±0.17% to 2.35±0.02% for F02 to Z350, respectively. The flowable materials had significantly higher shrinkage than did their sculptable counterparts (BF and Z350). Complex viscosities ranged from 9.65 to 4.20 (Z350 and F10, respectively) at a frequency of 10 rad/s and from 8.16 to 3.28 (Z350 and F03, respectively) for 100 rad/s. Giomer restorations had significantly less leakage than did those restored with nano-filled composites. No microleakage was observed with restorations lined with F02 or F10. The use of flowable liners reduced cervical microleakage of Class II restorations. Interfacial integrity of Class II restorations was significantly correlated with liner viscosity, filler volume, and shrinkage.

Marginal sealing of relocated cervical margins of mesio-occluso-distal overlays

We investigated the effect of cervical marginal relocation (CMR) on marginal sealing with two different viscosity resin composites, before adhesive cementation of composite computer-aided design/computer-assisted manufacture mesio-occluso-distal (MOD) overlays. Standardized MOD cavities prepared in 39 human molars were randomly assigned to three groups. The proximal margins on the mesial side were located 1 mm below the cementoenamel junction. On the distal side of the tooth, the margins were located 1 mm above the cementoenamel junction. In Groups 1 and 2, mesial proximal boxes were elevated with a hybrid composite (GC Essentia MD) and a flowable composite (GC G-ænial Universal Flo), respectively. CMR was not performed in Group 3. The overlays were adhesively cemented, and interfacial leakage was quantified by scoring the depth of silver nitrate penetration along the adhesive interfaces. Leakage score at the dentin-CMR composite interface did not significantly differ between the two tested composites but was significantly lower for Group 3. In all groups, scores were significantly higher at the dentin interface than at the enamel interface. These results indicate that the performance of flowable and microhybrid resin composites, as indicated by marginal sealing ability, is comparable for CMR.

Effect of Different Liners on Fracture Resistance of Premolars Restored with Conventional and Short Fiber-Reinforced Composite Resins

PURPOSE

To see whether applying four different liners under short fiber-reinforced composite (SFRC), everX Posterior, compared to conventional composite resin, Z250, affected their strengthening property in premolar MOD cavities.

MATERIALS AND METHODS

Mesio-occluso-distal (MOD) cavities were prepared in 120 sound maxillary premolars divided into 10 groups (n = 12) in terms of two composite resin types and 4 liners or no liner. For each composite resin, in 5 groups no liner, resin-modified glass ionomer (RMGI), conventional flowable composite (COFL), self-adhesive flowable composite resin (SAFL), and self-adhesive resin cement (SARC) were applied prior to restoring incrementally. After water storage and thermocycling, static fracture resistance was tested. Data (in Newtons) were analyzed using two-way ANOVA (α = 0.05).

RESULTS

Fracture resistance was significantly affected by composite resin type (p = 0.02), but not by the liner (p > 0.05). The interaction of the two factors was not statistically significant (p > 0.05). SFRC exhibited higher fracture strength (1470 ± 200 N) compared to conventional composite resin (1350 ± 290), irrespective of the application of liners. Application of SARC and SAFL liners led to a higher number of restorable fractures for both composite resins.

CONCLUSIONS

The four liners can be used without interfering with the higher efficacy of SFRC, compared to conventional composite resins, to improve the fracture strength of premolar MOD cavities.

Clinical Evaluation of a Silorane- and a Methacrylate-Based Resin Composite in Class II Restorations: 24-Month Results

OBJECTIVE

To compare the 24-month clinical performance of two different resin composites in class II slot restorations.

METHODS AND MATERIALS

Thirty-seven patients having at least two approximal carious lesions were enrolled in the study. A total of 116 teeth (58 pairs) were restored with either a silorane-based composite (Filtek Silorane) and its self-etch adhesive (Silorane Adhesive System, 3M ESPE) or a methacrylate-based packable resin composite (X-tra Fil) and its self-etch adhesive (Futurabond NR, VOCO GmbH) according to the toss of a coin. The restorations were evaluated at baseline and at six-, 12-, and 24-month recalls by two calibrated examiners according to the modified US Public Health Service criteria. The comparison of the two restorative materials for each category was performed with the Pearson chi-square test. Within group differences of the materials at different recall times were compared using the Cochran Q and Friedman tests. Bonferroni-adjusted McNemar test was used when significant difference was found (p<0.05).

RESULTS

After 24 months, no statistically significant differences were found between the two restorative materials for the criteria evaluated.

CONCLUSIONS

Both silorane- and methacrylate-based resin composites showed clinically acceptable performance in class II slot restorations after 24 months.

Clinical performance of Class I nanohybrid composite restorations with resin-modified glass-ionomer liner and flowable composite liner: A randomized clinical trial

Background:

Liners play a vital role in minimizing polymerization shrinkage stress by elastic bonding concept and increase the longevity and favorable outcome for composite restorations.

Aims:

The aim of this study was to evaluate the clinical performance of nanohybrid composite restorations using resin-modified glass-ionomer and flowable composite liners.

Settings and Design:

A single-centered, double-blinded randomized clinical trial, with split-mouth design and equal allocation ratio that was conducted in the Department of Conservative Dentistry and Endodontics.

Materials and Methods:

In forty patients, a total of eighty Class I restorations were placed with resin-modified glass-ionomer cement (RMGIC) liner (FUJI II LC, GC America) in one group and flowable composite liner (smart dentin replacement/SDR, Dentsply Caulk, Milford, DE, USA) in another group. All restorations were clinically evaluated by two examiners, immediately (baseline), 3, 6, and 12 months using US Public Health Service modified criteria.

Statistical Analysis Used:

Statistical analysis was performed using McNemar's test (P < 0.05).

Results:

There was no significant difference in the color match, marginal discoloration, surface roughness, and marginal adaptation. Restorations with RMGIC liner group show 20% Bravo scores on anatomic form at 12 months but are still clinically acceptable.

Conclusion:

Nanohybrid composite restorations with RMGIC (Fuji II LC) and flowable composite liner (SDR) demonstrated clinically acceptable performance after 12 months.

Microcomputed Tomography Evaluation of Volumetric Shrinkage of Bulk-Fill Composites in Class II Cavities

PURPOSE

This study aimed to quantify polymerization shrinkage of one conventional and three bulk-fill composites, under bonded and unbonded conditions, in Class II preparations using 3D microcomputed tomography (μCT) and report its location.

MATERIALS AND METHODS

Preparations (2.5 mm occlusal depth × 4 mm wide × 4 mm mesial box and 1 mm beyond the CEJ distal box depth) were made in 48 human extracted molars (n = 6). Four composites were tested, one regular (Vitalescence/VIT) and three bulk-fill: SureFil SDR Flow (SDR), Tetric EvoCeram Bulk Fill (TET), and Filtek flowable Bulk Fill (FIL). Teeth were divided into four groups according to restorative material used and subdivided into two subgroups, according to the presence of an adhesive system (XP Bond) application (bonded [-B]) or its absence (unbonded [-U]). Each tooth was scanned three times: (1) after cavity preparation, (2) before and (3) after composite light-curing. Acquired μCT images were imported into 2D and 3D software for analysis.

RESULTS

Significantly different volumetric shrinkage between bonded and unbonded conditions was observed only for TET group (p < 0.05), unbonded presenting significantly higher volumetric shrinkage. Among the bonded groups, TET-B presented significantly lower shrinkage than both SDR-B and FIL-B but not significantly different from VIT-B. Generally, shrinkage occurred at occlusal and distal surfaces.

CONCLUSIONS

When applied to bonded Class II cavities, TET exhibited significantly lower volumetric shrinkage compared to the other bulk-fill composites. However, it also exhibited the highest difference of volumetric shrinkage values between unbonded and bonded cavities.

CLINICAL SIGNIFICANCE

Volumetric polymerization shrinkage occurred with all composites tested, regardless of material type (conventional or bulk-fill) or presence or absence of bonding. However, volumetric shrinkage has been reduced or at least maintained when bulk-fill composites were used compared to a conventional composite resin, which makes them a potential time saving alternative for clinicians. (J Esthet Restor Dent 29:118-127, 2017).

Marginal integrity of restorations produced with a model composite based on polyhedral oligomeric silsesquioxane (POSS)

Marginal integrity is one of the most crucial aspects involved in the clinical longevity of resin composite restorations.

Push-Out Bond Strength of Restorations with Bulk-Fill, Flow, and Conventional Resin Composites

The aim of this study was to evaluate the bond strengths of composite restorations made with different filler amounts and resin composites that were photoactivated using a light-emitting diode (LED). Thirty bovine incisors were selected, and a conical cavity was prepared in the facial surface of each tooth. All preparations were etched with Scotchbond Etching Gel, the Adper Scotchbond Multipurpose Plus adhesive system was applied followed by photoactivation, and the cavities were filled with a single increment of Filtek Z350 XT, Filtek Z350 XT Flow, or bulk-fill X-tra fil resin composite (n = 10) followed by photoactivation. A push-out test to determine bond strength was conducted using a universal testing machine. Data (MPa) were submitted to Student's t-test at a 5% significance level. After the test, the fractured specimens were examined using an optical microscope under magnification (10x). Although all three composites demonstrated a high prevalence of adhesive failures, the bond strength values of the different resin composites photoactivated by LED showed that the X-tra fil resin composite had a lower bond strength than the Filtek Z350 XT and Filtek Z350 XT Flow resin composites.

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

OBJECTIVES

To determine microleakage of posterior Class I and II restorations using the SonicFill composite resin system.

METHODS AND MATERIALS

Eighty previously extracted third molars were randomly assigned to four preparation/restoration groups (n=20): Group A: Class I preparations restored with SonicFill system/bulk fill; Group B: Class II preparations restored with SonicFill system/bulk fill; Group C: Class I preparations restored with Herculite Ultra composite resin/incremental technique; and Group D: Class II preparations restored with Herculite Ultra composite resin/incremental technique. Class I preparations were approximately 3.0 mm in width buccolingually and 3.0 mm in depth. Class II preparations were approximately 3.0 mm in width buccolingually, 1.5 mm in axial depth, and 4.0 mm in gingival depth. In all groups, the enamel and dentin surfaces were conditioned with Kerr 37.5% phosphoric acid, followed by application of Optibond Solo Plus adhesive system. Following restoration, the specimens were thermocycled, immersed in methylene blue dye, and embedded in acrylic resin. Specimen blocks were sectioned in the mesiodistal direction, with marginal dye penetration (microleakage) examined using a 20× binocular microscope. Class I and II restoration microleakage was scored separately using a 0-3 ordinal ranking system. Statistical analyses were conducted using nonparametric testing at the p < 0.05 level of significance.

RESULTS

Significantly less microleakage was associated with both Class I restorative groups (A and C), SonicFill bulk fill and Herculite Ultra incremental fill, compared to the Class II restorative groups (B and D), SonicFill/bulk fill and Herculite Ultra/incremental fill.

CONCLUSIONS

According to the results of this study, the materials (SonicFill vs Herculite Ultra), C-factors, and insertion techniques (bulk vs incremental) did not appear to be significant influences with regard to marginal microleakage; however, the type of preparation cavity (Class I vs Class II) and the subsequent bonding surface (enamel vs dentin [cementum]) proved to be significant factors.