Bulk-fill Composite Restorations Research Articles

Effect of Radiotherapy on the Adhesive Interface of Caries-affected Dentin and Bioactive Restorations: A Micro-CT Analysis.

This study aimed to analyze the presence of defects within the adhesive interface formed with five bioactive dental materials and caries-affected dentin concerning the timing of radiotherapy (before or after the restorative procedures) by micro-CT. A total of 96 carious human molars were randomly allocated into the following groups based on the timing of the radiotherapy sequence: radiotherapy followed by restoration (RT1) or restoration followed by radiotherapy (RT2). Then, six subgroups were established within these groups based on the type of materials used (n=8). Following cavity preparation and caries removal, a universal adhesive (G-Premio Bond) was administered in self-etch mode or accompanied by applying suitable cavity conditioners according to the manufacturers' guidelines. Subsequently, restorations were performed using five bioactive restorative materials (resin-modified glass-ionomer [Fuji II LC], high-viscosity glass-ionomer hybrid [EQUIA Forte HT], giomer [Beautifil II], alkasite [Cention N], and dual-cure bulk-fill composite [Activa Bioactive Restorative]) and a conventional microhybrid resin composite (Filtek Z250). The radiotherapy regimen encompassed 60 Grays (Gy) administered at a rate of 2 Gy/day over 6 weeks, 5 days a week. Micro-CT analysis was employed to assess adhesive defects at the interface between caries-affected dentin and the restorations. The data were analyzed using Kruskal-Wallis, Mann-Whitney U, and Dunn tests (α=0.05). RT2 caused significantly higher adhesive defects than RT1 for the Filtek Z250 and Activa Bioactive Restorative subgroups (p<0.05). For RT1, no significant differences were found in adhesive defects among all tested subgroups (p>0.05). By contrast, for RT2, adhesive defects were significantly higher for the Activa Bioactive Restorative and Cention N subgroups than for the EQUIA Forte HT and Beautifil II subgroups (p<0.05). When using most bioactive restorative materials, the timing of radiotherapy had no significant influence on the adhesive interface. Regarding restoration following a radiotherapy protocol, a favorable impact was identified with high-viscosity glass ionomer hybrid cement and giomer bioactive restorations compared with dual-cure bioactive bulk-fill composite and alkasite restorations.

The 24 months clinical evaluation of class II bulk fill composite restorations

Background: Resin Composite materials are widely used in daily clinical dentistry because of their moderate cost compared with ceramics, easy placement, adequate esthetics, ability to bond with enamel and dentine, and physico-chemical properties. Bulkfill composite materials were introduced to reduce chairside time. These materials have properties such as optimal bond strength, decreased polymerization shrinkage, and reduced cuspal deflection. This in-vivo study compared the clinical performance of three different class II resin composite restorations. Methods: Seventy-one patients (41 females and 30 males) aged 20–43 years with at least three approximal caries were included in the present study. Two hundred twenty-three teeth with approximal caries were restored with two bulk-fill composites (Tetric-N Ceram Bulk fill [TEC], Filtek Bulk Fill [FB]) and a posterior resin composite (Gradia Direct Posterior [GDP]). Two experienced dentists clinically evaluated the restorations with a 5x magnification loupe using the modified United States Public Health Service (USPHS) criteria at baseline and at 24 months. Results: The chi-square test was performed for statistical analysis. The cumulative retention rate for all restorations at 24 months was 90.5%. Retention loss was observed for three TEC (6.1%), four FB (8.2), and seven GDP (14%) restorations. There was no statistically significant difference among the three resin composite restoration groups in color match, marginal adaptation, surface roughness, marginal discoloration, anatomical form, and secondary caries criteria (P&gt;0.05). Conclusion: Bulk-fill composite restorations in class II slot cavities have the same clinical results as traditional posterior composite restorations.

Clinical performance of posterior restorations using a universal adhesive over moist and dry dentin: A 36-month double-blind split-mouth randomized clinical trial

ObjectivesTo evaluate the influence of dentin moisture on the clinical behavior of a universal adhesive on posterior teeth after 36 months of follow-up. MethodsForty-five patients participated in this study. Following a split-mouth design, three operators placed 90 Class I/Class II restorations over moist dentin (MD) or dry (DD) (n = 45) with resin composite (Filtek Bulk Fill) and a universal adhesive used in the etch-and-rinse mode (Single Bond Universal). Each restoration was evaluated according to the FDI and USPHS criteria (postoperative sensitivity, fracture and retention, marginal staining, marginal adaptation, and recurrence of caries) at baseline and after 6-, 12-, and 36 months. For statistical analysis, Kruskal Wallis analysis of variance rank (α = 0.05) and Kaplan-Meier survival analysis were used. ResultsNo significant difference between groups was observed in each FDI criterion after 36 months of clinical evaluation (p > 0.05). The retention rates (confidence interval 95 %) were 97.37 % (86.5 - 99.5) for both MD and DD without significant difference between them (p > 0.05). Eight restorations (MD = 4; DD = 4) showed minimal marginal staining defects (p > 0.05). Two restorations were lost (MD = 1; DD = 1). Fifteen restorations (MD = 8; DD = 7) presented minor marginal discrepancies according to the FDI criteria (p > 0.05). ConclusionThe clinical performance of the universal adhesive when applied in etch-and-rinse mode was not influenced by dentin moisture in posterior bulk-fill composite restorations. Clinical significanceThe level of dentin moisture appears not to influence the clinical efficacy of a universal adhesive when applied using the etch-and-rinse technique in posterior composite resin restorations.

The effect of flowable composite and glass ionomer liner on the marginal integrity of class II composite resin restorations

Aim of the study To evaluate the effect of flowable composite and glass ionomer liner on the marginal integrity of Class II composite resin restorations. Materials and methods A total of thirty non-carious human maxillary molar teeth were mounted in acrylic blocks. Simple Class II cavity with parallel walls was prepared. The cervical margin was established 1.5 mm above the cemento- enamel junction. The overall dimensions and depth of the cavities were standardized as follow: 4 mm length occlusocervically, 4 mm width buccolingulaly and 2 mm depth axially. Specimens were randomly divided into three equal groups (10 each). Group 1: The cavities were restored with Xtra Fil bulk fill composite without liner. Group 2: Xtra base flowable composite (1 mm thickness) was applied, followed by Xtra Fil bulk fill. Group 3: Ionoseal glass ionomer was applied as a base (1 mm thickness), followed by Xtra Fil bulk. Specimens were then subjected to 500 thermal cycles from 5 to 55oC with 30 s dwell time, and 15 s transfer time. Impressions of the teeth were made using a polyvinyl siloxane material, poured with epoxy resin. These replicas were left 24 h for complete setting. Then, Gold sputtered to be examined under scanning electron microscopy (SEM). Results were expressed as percentage of open margins for the total margin length for proximal and cervical margins and also the width of the gap were measured. The recorded data was collected, tabulated, and statistically analyzed using SPSS version 25. Results It was found that there was a significant difference in total gap length between group 1 and group 2 with P value = 0.000. Where group 1 has the biggest marginal gap length and the smallest marginal gap length belongs to Group 2. While there was no significant difference between group 1 and group 3 with P value 0.124. It was also found that there was no significant difference between groups in marginal gap widths. Conclusions The use of flowable composite and glass ionomer as liner could reduce microleakage of bulkfill composite restorations.

Bulk-flow composites in paediatric dentistry: long term survival of posterior restorations. A retrospective study.

Dental decay is a prevalent bacterial disease affecting a significant percentage of children globally. In paediatric dentistry, various materials are available for restoring deciduous teeth, addressing both functional and aesthetic concerns. However, paediatric dentists encounter challenges related to patient compliance, limited working time, and material handling. This study aims to observe the survival rate of bulk-fill composite restorations in paediatric patients over a five-year follow-up. A total of 198 patients aged 0 to 12 years underwent 673 class II restorations on deciduous first molars (1M) and second molars (2M). All restorations were conducted performed by 1 Pediatric DDS resident students from the Paediatric Dentistry Department (Padova University), utilizing using different isolation techniques. Bulk-fill composite restorations were evaluated over a five-year follow-up, and data were collected by a single investigator. After five years, 177 patients and 611 restorations were assessed. The retention rate was higher in primary second molars than in first molars, with fewer marginal dyschromies and less formation of secondary caries. The overall failure rate was higher in primary first molars and primary lower second molars. Bulk-fill composites demonstrated significantly positive performance in terms of retention, maintenance, and marginal dyschromies. Bulk-fill composites are promising materials of choice in paediatric dentistry due to their easy handling and favorable properties. Further research is necessary to compare high and low viscosity bulk-fill composites and assess the impact of different variables on restoration success.

Influence of surface sealants on the quality of posterior restorations with bulk-fill composites: A 4-year randomized clinical trial

ObjectivesThe aim of this study was to evaluate the clinical performance of surface sealants associated with a bulk-fill composite in posterior restorations after 4 years. MethodsA total of 174 posterior restorations were performed on 57 participants using a self-etch adhesive system and a bulk-fill composite. The groups were then divided into the following categories: 1) without surface sealant (NoS), 2) with surface sealant Biscover (Bisco, SBi), and 3) with surface sealant Permaseal (Ultradent, SPe). Restorations were evaluated using FDI criteria at baseline and after 1 and 4 years. Statistical analysis was conducted using Kaplan-Meier survival analysis and the Chi-square test (α = 0.05). ResultsAfter 4 years, only one restoration was lost (1 in the NoS group). The fracture/retention rate (with 95% confidence interval) was 98% for NoS and 100% for both SBi and SPe (p = 0.76). The majority of secondary outcomes showed minor defects, with no significant differences among the groups (p > 0.05). However, significant differences were observed among the groups in terms of marginal staining and marginal adaptation (p = 0.03). In both items, twelve restorations (nine in NoS, one in SBi, and two in SPe) showed minor marginal discrepancies favoring the sealant groups (SBi and SPe). SignificanceRegardless of the use of surface sealants, the bulk-fill composite restorations showed excellent clinical performance after 4 years. However, the groups that received sealants showed better marginal adaptation and less marginal discoloration compared to those that did not receive sealants.

A laboratory pilot study on voids in flowable bulk-fill composite restorations in bovine Class-II and endodontic access cavities after sonic vibration

This pilot study investigated whether sonic-powered application of a bulk-fill resin-based composite (RBC) in Class-II or endodontic access cavities reduces void formation. The crowns and roots of 60 bovine teeth with Class-II cavities (C) and endodontic access cavities (E) respectively, were assigned to ten groups (C1–C5, E1–E5). Cavities were filled with RBC (SDR flow + , one increment) using different application techniques: no adaptation (C1 + E1), spreading of RBC on the cavity surfaces with a dental explorer tip (C2 + E2), low (C3 + E3) or high frequency (C4 + E4) direct activation by inserting a sonic-powered tip into RBC and high frequency indirect activation with an ultrasonic insertion tip (C5 + E5). The restorations were light-cured and investigated for voids using microtomography. The number of voids and percentage of voids related to the volume were statistically analysed (α < 0.05). While most voids in Class-II restorations were observed in C4 (p ≤ 0.0031), no significant differences were found between the other groups (p > 0.05). The percentage of voids showed no differences in E1-E5 (p > 0.05). C4 showed a significantly higher percentage of voids compared to C2 (p < 0.001). There is no benefit in applying sonic vibration when filling Class-II or endodontic access cavities.

A Randomized Controlled Clinical Trial Evaluating the Performance of Bis-GMA Free Resin Composite Posterior Restorations

Objective: This study aims to assess the clinical performance of Bis-GMA free resin composites (RCs) in comparison with Bis-GMA based resin composites as posterior restorations during 1,3,6,9, and 12 months, using a split-mouth, double-blinded randomized design. Methods and Materials: The study included 20 participants who received a pair of class I or II bulk-fill composite restorations. One side of the mouth was filled with Bis-GMA free RC (Admira Fusion x-tra), while the other side received Bis-GMA based RC (X-tra fil). Restoration placement was done by a single operator following the manufacturer's guidelines and was finished and polished immediately following placement. Modified United States Public Health Services (USPHS) criteria have been adopted for restoration assessment at baseline (1 week), 1, 3, 6, 9, and 12 months. The statistical analysis was accomplished utilizing Wilcoxon tests, with a 0.05 significance level. Results: After 12 months, all patients attended the recall visits with a 100% recall rate. The Wilcoxon signed rank tests revealed insignificant differences between both groups (p?0.05) for all USPHS parameters. The two studied materials showed a decline from 100% clinically excellent scores, with a few recordings of clinically good scores at 12 months. However, most restorations maintained clinical Alpha and Bravo score throughout the 12-month period. Conclusions: The Bis-GMA-free RCs' clinical performance was comparable to that of Bis-GMA-based RCs in posterior permanent teeth restorations after 12 months. These findings suggest that Bis-GMA-free RCs can be considered a viable alternative to Bis-GMA-based RCs in clinical practice.

Marginal Integrity of Simplified Adhesive Strategies in Primary Teeth

The aim of this research was to investigate the effect of simplified adhesive strategies (self-etch vs selective enamel etch and 10- vs 20-second adhesive application time) on the marginal integrity in primary molars. Forty deep class-II cavities were prepared in 40 extracted primary molars. The molars were divided into 4 groups based on the applied universal adhesive strategy as follows: groups 1 and 2: selective enamel etch with 20- or 10-second application time and groups 3 and 4: self-etch with 20- or 10-second application time. All cavities were restored with a sculptable bulk-fill composite restoration. The restorations underwent a thermomechanical loading (TML, 5-50 °C, 2-minute dwelling time, ×1000; 400,000 loading cycles, 1.7 Hz, 49 N). Marginal analysis before and after TML was conducted with scanning electron microscopy and the marginal integrity of each restoration was calculated as a percentage of continuous margins. A beta regression model was adopted to statistically analyse the data with a consequent pairwise comparison. The mean marginal integrity (% ± SD) of the restorations for each tested adhesive strategy after TML was as follows: selective enamel etch/20 seconds=85.4 ± 3.9, self-etch/20 seconds=85.3 ± 5.2, self-etch/10 seconds=80.1 ± 8.2, and selective enamel etch/10 seconds=80.0 ± 8.5. The difference between both adhesive strategies was not statistically significant at the same application time. The difference between both application times within the same adhesive strategy was statistically significant (P ≤ .01). Universal adhesives applied either in selective enamel etch or in self-etch mode result in comparable marginal integrities when restoring class-II cavities in primary molars. Shortened adhesive application time (10 seconds) could lead to a reduction in the marginal integrity in comparison to the recommended application time of 20 seconds.

Microleakage and Marginal Integrity of Ormocer/Methacrylate-Based Bulk-Fill Resin Restorations in MOD Cavities: SEM and Stereomicroscopic Evaluation.

This in vitro study aimed to compare the microleakage and marginal integrity of methacrylate/ormocer-based bulk-fill composite (BFC) restorations used in cervical marginal relocation with two different layering thicknesses in mesio-occlusal-distal (MOD) cavities exposed to thermo-mechanical loading. Standard MOD cavities were prepared in 60 mandibular molars and assigned into three groups: x-tra fil/AF + x-tra base/XB, Tetric N-Ceram Bulk Fill/TNB + Tetric N-Flow Bulk Fill/TFB, and Admira Fusion x-tra/AFX + Admira Fusion x-base/AFB. Each group was further divided into two subgroups (2 mm and 4 mm) based on the thickness of flowable BFCs (n = 10). The specimens were subjected to thermo-mechanical loading (240,000 cycles) and immersed in 0.2% methylene blue. Following mesiodistal sectioning, the specimens were examined under stereomicroscope (×25) and scored (0-3) for microleakage. Marginal integrity was examined using a scanning electron microscope (SEM). Descriptive statistical methods and the chi-square test were used to evaluate the data (p < 0.05). While there was no statistically significant difference in gingival cement microleakage in the XB and AFB specimens with a 4 mm thickness, microleakage was significantly increased in the TFB specimen (p = 0.604, 0.481, 0.018 respectively). A significantly higher amount of score 0 coronal microleakage was detected in the AFX2 mm + AFB4 mm compared to the TNB2 mm + TFB4 mm (p = 0.039). The SEM examination demonstrated better marginal integrity in groups with 2 mm thick flowable BFCs. Ormocer and methacrylate-based materials can be used in marginal relocation with thin layers.

Clinical comparison of different glass ionomer-based restoratives and a bulk-fill resin composite in Class I cavities: A 48-month randomized split-mouth controlled trial

ObjectiveThe aim of this study is to compare the retention rates (primary outcome) of high-viscosity glass ionomer (GI), glass carbomer (GC), zirconia-reinforced GI (ZIR), and bulk-fill (BF) composite resin restorations. Secondary outcomes included anatomical form, marginal adaptation, marginal discoloration, color match, surface texture, post-operative sensitivity and secondary caries. MethodsTwo calibrated operators placed 128 restorations in 30 patients with a mean age of 21 years. The restorations were evaluated by one examiner at baseline and at 6, 12, 18, 24, and 48 months using the modified US Public Health Service criteria. The data were statistically analyzed using Friedman test. Differences between restorations were analyzed using Kruskal–Wallis test. ResultsAfter 48 months, 23 patients and 97 restorations (23 GI, 25 GC, 24 ZIR, and 25 BF) were evaluated. Patient recall rate was 77%. No significant difference was observed between the retention rates of the restorations (p > 0.05). GC showed significantly lower results than the other three fillings in terms of anatomical form (p < 0.05). There was no significant difference in the anatomical form and retention between GI, ZIR, and BF (p > 0.05). No significant change was observed in the postoperative sensitivity or secondary caries for any of the restorations (p > 0.05). ConclusionsGC restorations showed statistically lower anatomical form values, indicating lower wear resistance than the other materials. However, no significant difference was observed in the retention rates (as primary outcome) as well as the other secondary outcomes of the four different restorative materials after 48 months. Clinical SignificanceGI-based restorative materials and BF composite resin restorations in Class I cavities yielded satisfactory clinical performance after 48 months.

Effect of radiant emittance of an LED curing light on the cuspal deflection of a simulated tooth cavity in bulk-fill composite restoration: A novel simulation method.

In this study, a novel method for simulating human teeth was developed, with which the effect of radiant emittance of an LED curing light on the cuspal deflection was investigated. A mesio-occluso-distal (MOD) cavity was replicated using a heat-pressed ceramic and lost wax technique, and the cuspal compliance and cuspal deflection of the replicated ceramic teeth and extracted human teeth were evaluated. The replicated ceramic teeth were restored using a nano bulk-fill composite and photopolymerized using three different protocols. Data were analyzed with t-test and one-way ANOVA (α=0.05). The cuspal compliance and cuspal deflection of the replicated ceramic teeth and extracted human teeth were similar. Cuspal deflections did not differ significantly among the tested photopolymerization protocols. Thus, the replicated ceramic teeth were an effective simulation of human teeth. During bulk-fill composite restoration of the MOD cavity, cuspal deflection was not affected by changing the radiant emittance of the LED light.

Marginal integrity of classical and bulk-fill composite restorations in permanent and primary molars

Bulk-fill composites enable timesaving and less technical-sensitive application of restorations. This study investigated and compared the marginal integrity of classical and bulk-fill composite restorations in primary and permanent molars before and after thermo-mechanical loading (TML). Two Class II cavities were prepared in each of 20 primary and 20 permanent molars. The molars were randomised in four groups for each molar type. Groups 1 and 5 were restored with a high-viscous bulk-fill composite (Tetric PowerFill), groups 2 and 6 were restored with a flowable bulk-fill composite (Tetric PowerFlow), groups 3 and 7 were restored with a high-viscous classical composite (Tetric Prime), and groups 4 and 8 were restored with a flowable classical composite (Tetric EvoFlow). In permanent molars, the flowable composites were covered with a 2-mm layer of high-viscous composite (groups 6 and 8). The restorations were subjected to TML in a custom-made chewing machine (5–50 °C, 2 min dwelling time, × 1000; 400 ,000 loading cycles, 1.7 Hz, 49 N), and quantitative marginal analysis was conducted using scanning electron microscopy. Marginal integrity of each restoration was calculated as a percentage of continuous margins before and after TML. The tested high-viscous bulk-fill restoration showed similarly high marginal integrity in primary and permanent molars as the classical restoration. The tested flowable bulk-fill restoration showed the lowest marginal integrity compared to all other restorations after TML. In contrast to flowable bulk-fill restorations, high-viscous bulk-fill restorations show similar marginal integrity as classical hybrid composite restorations after TML, in both primary and permanent molars.

Influence of Practitioner-Related Placement Variables on the Compressive Properties of Bulk-Fill Composite Resins-An In Vitro Clinical Simulation Study.

Aims: To determine if restoration location and/or execution behavior force parameters have an influence on the mechanical properties of bulk-fill composite dental restorations. Methods: Pressure transducers were placed within each quadrant of dental mannequin jaws. Cylindrical molds were placed above the transducers and filled with two bulk-fill composite materials, Filtek and Tetric, by four experienced dentists. Each dentist prepared five specimens per quadrant and material. The total placement time, mean force, number of peak forces (above 25 N), and mean peak(s) force during placement were measured. Then, the stiffness and maximal compressive strength of the specimens were determined while loading the specimens up to failure using a universal loading machine. Results: Placement time was affected by jaw (p < 0.004) and side (p < 0.029), with the shortest time demonstrated for the left side of the mandible. Force exerted during restoration placement was not normally distributed without differences in location (jaw) or material. A higher application force was found on the right side (p < 0.01). The number of peak forces was affected by side (p < 0.03), with less peaks on the left side. No significant differences were found in compressive strength when correlated to restoration location, participant, or material (p = 0.431). The stiffness values of Filtek (3729 ± 228 N/mm) were found to be 15% higher than Tetric (3248 ± 227 N/mm) (p < 0.005). No correlations were found between the compressive strength or stiffness and the amount of force applied during placement. Conclusions: The individual restoration material placement parameters did influence practitioner performance; however, these differences did not affect the mechanical properties of the final restoration.

Influence of Matrix Type on Marginal Gap Formation of Deep Class II Bulk-Fill Composite Restorations.

Background: To test the hypothesis that transparent matrices result in more continuous margins of bulk-fill composite (BFC) restorations than metal matrices. Methods: Forty standardized MOD cavities in human molars with cervical margins in enamel and dentin were created and randomly assigned to four restorative treatment protocols: conventional nanohybrid composite (NANO) restoration (Tetric EvoCeram, Ivoclar Vivadent, Schaan, Liechtenstein) with a metal matrix (NANO-METAL) versus transparent matrix (NANO-TRANS), and bulk-fill composite restoration (Tetric EvoCeram Bulk Fill, Ivoclar Vivadent, Schaan, Liechtenstein) with a metal matrix (BFC-METAL) versus transparent matrix (BFC-TRANS). After artificial aging (2500 thermal cycles), marginal quality was evaluated by scanning electron microscopy using the replica technique. Statistical analyses were performed using the Mann–Whitney U-test and Wilcoxon test. The level of significance was p < 0.05. Results: Metal matrices yielded significantly (p = 0.0011) more continuous margins (46.211%) than transparent matrices (27.073%). Differences in continuous margins between NANO (34.482%) and BFC (38.802%) were not significant (p = 0.56). Matrix type did not influence marginal gap formation in BFC (p = 0.27) but did in NANO restorations (p = 0.001). Conclusion: Metal matrices positively influence the marginal quality of class II composite restorations, especially in deep cavity areas. The bulk-fill composite seems to be less sensitive to the influence of factors such as light polymerization and matrix type.

Bond strength of bulk-fill resin composites

Aim: Evaluating the resin-dentin bond strength of Class II conventional and bulk-fill composite restorations, using different cavity sizes before and after aging. Methods: Seventy-five human molars were distributed into groups according to the buccolingual width of the cavities, conservative (n=25) and extended (n=50). They were divided according to the restorative material: conventional (Z100/control group) or bulk-fill resin composites (Filtek Bulk Fill/FBF; Tetric N Ceram Bulk Fill/TNCBF; Filtek Bulk Fill Flow/FBFF; Surefill SDR flow/SDR). The restored teeth were sectioned on sticks (n=50 per restorative materials + width cavities group), half were stored in Water/Ethanol 75% for 30 days and the other half were submitted to the immediate microtensile bond strength (μTBS) test. Data were analyzed applying the Three-Way Analysis of Variance (ANOVA), Bonferroni test, test t, and Weibull analyses (p&lt;0.05). Results: SDR and FBF presented lower μTBS values for extended preparation when compared to the conservative preparation, before aging. After aging, only for the FBFF, a decrease in the μTBS values was observed. Comparing the μTBS values, before and after aging, the SDR demonstrated lower μTBS values after aging when the conservative cavity was used. A decrease in the μTBS values was observed for the Z100, the FBF and, the FBFF, after aging, when the extended cavity was used. Conclusion: The effect of cavity preparation and aging on the resin-dentin of Class II is material dependent. Most of the bulk-fill resin composites evaluated presented a similar performance to the conventional resin composites for all the conditions of this study.

Effect of Dentin Moisture in Posterior Restorations Performed with Universal Adhesive: A Randomized Clinical Trial.

This double-blind, randomized clinical trial evaluated the influence of dentin moisture on postoperative sensitivity (POS), as well as, on clinical performance in posterior bulk-fill composite restorations, using a universal adhesive, until 12 months after clinical service. In accordance with a split-mouth design, 45 patients received posterior restorations, restored with a bulk-fill resin composite (Filtek Bulk Fill, 3M Oral Care) and a universal adhesive used in etch-and-rinse mode (SBU; Single Bond Universal Adhesive), which were applied on dry or moist dentin, with a cavity depth of at least 3 mm. Three operators placed 90 Class I/Class II restorations. Patients were evaluated for spontaneous and stimulated POS in the baseline, and after 48 hours, 7 days, and at 6 and 12 months. In addition, secondary parameters (marginal discoloration, marginal adaptation, fracture, and recurrent caries) were evaluated by World Dental Federation (FDI) criteria after 7 days and at 6 and 12 months. Statistical analyzes were performed using the Chi-square, Fisher exact, Friedman, Kruskall-Wallis, and Mann-Whitney tests (α=0.05). No significant spontaneous and stimulated POS was observed when SBU was applied in dry and moist dentin (p>0.05). A significant and higher risk of spontaneous POS (20.0%; 95%CI 10.9-33.82 for dry dentin and 22.22%; 95%CI 12.54-36.27 for moist dentin) occurred up to 48 hours after restoration placement for the dry and moist dentin groups (p<0.02). However, the POS intensity was mild up to 48 hours with no significant difference between dry and moist dentin groups (p>0.79). When secondary parameters were evaluated, no significant differences between the groups were observed. Dentin moisture did not influence POS in posterior bulk-fill composite restorations when associated with a universal adhesive applied in etch-and-rinse mode.

One-year clinical evaluation of bulk-fill composite resin restorations plasticized by preheating and ultrasonics: A randomized clinical trial.

Introduction:Bulk-fill composite restorations displayed substantial annual failure related to imperfect marginal adaptation. Although preheated composites improved, marginal adaptation demonstrated early loss of plasticity. A new technique of ultrasonics plasticization was used for fabricating restorations.Aim:The aim of this study was to assess the clinical behavior of bulk-fill composite resin restorations plasticized by preheating and ultrasonics.Methodology:Randomized split-mouth double-blinded clinical trial was designed. Bulk-fill composite resin (Tetric N-Ceram Bulk Fill Ivoclar Vivadent products, Delhi) was used to fill 56 cavities. In 28 restorations, composite resin was plasticized by preheating in composite warmer (Delta Co., India) and remaining were plasticized with modified ultrasonic–retreatment tip-RT No 2 (Cricdental, India). Clinical follow-up assessments were done at 6 and 12 months using Ryge's criteria. Mann–Whitney U-test was used for statistical analysis with P < 0.05 and effect size of 0.61.Results:Hundred percent clinical success with ultrasonic plasticized group and 95.2% success with preheated composite resin group were observed without statistical significance.Conclusion:The ultrasonics plasticization of composite resin demonstrated comparable results with that of preheated composite resin after 6- and 12-month recall. Use of vibration energy utilizing the thixotropic effect might have resulted in better clinical performance.

Evaluation of the Quality of Margins in Class ІІ Bulk Fill Composite Restorations when Restored in Bulk and in the Incremental Filling Technique Using the Total Etch and Self Etch Technique

Objective: To evaluate the marginal quality of class II composite restorations using a bulk fill composite when restored in bulk compared to an incremental filling technique following two different modes of bonding, total etch and self-etch technique. Methods: Forty-eight standardized class II box-shaped cavities were prepared on both the proximal surfaces of twenty-four mandibular molar teeth. Cavities were prepared with no-245 carbide bur on proximal surfaces. The teeth were divided into two groups, Group 1 which followed the self-etch strategy (n=12) and Group 2 which followed a total etch strategy (n=12). Each group was further divided into two subgroups based on the restorative technique followed, Sub group A – cavities on the mesial side which were bulk filled and Sub group B – cavities on the distal side which were incrementally filled. Specimens were placed in 2% methylene blue dye for 24 hrs and were then sectioned. Specimens were evaluated under stereomicroscope for microleakage. Data obtained was statistically analyzed using Kruskal Wallis test and Dunn’s multiple comparison test. Results: The results showed that between the two groups, the total etch technique showed the highest microleakage. Greater microleakage was observed in bulk fill technique when compared with incremental technique in group II. Conclusion: The degree of microleakage in a class II composite restoration is influenced not only by the adhesion strategy followed for the bonding agent, but also by the technique followed during composite restoration

Micro-computed tomography for assessing the internal and external voids of bulk-fill composite restorations: A technical report.

PurposeThis technical report aims to describe and detail the use of micro-computed tomography for a reliable evaluation of the bulk-fill composite/tooth interface.Materials and MethodsBulk-fill composite restorations in tooth cavities were scanned using micro-computed tomography to obtain qualitatively and quantitatively valuable information. Two-dimensional information was processed using specific algorithms, and ultimately a 3-dimensional (3D) specimen reconstruction was generated. The 3D rendering allowed the visualization of voids inside bulk-fill composite materials and provided quantitative measurements. The 3D analysis software VG Studio MAX was used to perform image analysis and assess gap formation within the tooth-restoration interface. In particular, to evaluate internal adaptation, the Defect Analysis add-on module of VG Studio Max was used.ResultsThe data, obtained with the processing software, highlighted the presence and the shape of gaps in different colours, representing the volume of porosity within a chromatic scale in which each colour quantitatively represents a well-defined volume.ConclusionMicro-computed tomography makes it possible to obtain several quantitative parameters, providing fundamental information on defect shape and complexity. However, this technique has the limit of not discriminating materials without radiopacity and with low or no filler content, such as dental adhesives, and hence, they are difficult to visualise through software reconstruction.