Resin Restorations Research Articles

Fracture strength of implant-supported hybrid abutment crowns in premolar region fabricated using different restorative CAD/CAM materials.

The present study investigated the fracture strength of hybrid abutment crowns (HACs) in the premolar region that were fabricated with different restorative computer-aided design/computer-aided manufacturing (CAD/CAM) materials. The abutment-implant structures were randomly assigned into four groups (n=11 per group): bi-layered zirconia restorations (BL), translucent zirconia (4Y-PSZ) restorations (TZ), lithium disilicate ceramic restorations (LD), and dispersed nanoparticle-filled composite resin restorations (CM). All restorations were adhesively bonded to the titanium abutments. After the restoration-abutment complex was tightened onto the implant, the fracture strength was measured. The TZ (2.06 kN) and LD (1.87 kN) groups had significantly higher median fracture strengths than the BL (1.12 kN) and CM (1.10 kN) groups. In terms of fracture resistance, the 4Y-PSZ and lithium disilicate ceramic monolithic restorations would be superior to bi-layered 3Y-TZP and composite resin monolithic restorations for HACs in the premolar region.

Influence of Phosphoric Acid Etching on Bond Strength for Calcium Silicate-Based Sealers

IntroductionThis study evaluated the microtensile bond strength of calcium silicate-based sealers and epoxy resin-based sealer, depending on the use of phosphoric acid (PA) etching before immediate resin restoration. MethodsExposed dentin surfaces of extracted human third molars were randomly assigned to 3 groups depending on sealer type (AH Plus [Dentsply DeTrey], CeraSeal [Meta Biomed Co.], and EndoSeal MTA [Maruchi]). Half of the samples were treated with PA for 30 seconds, and the other half were cleaned with water. Completely untreated specimens were used as controls. Self-etching adhesive (Clearfil SE Bond, Kuraray) was applied and composite resin (Tetric N-Ceram, Ivoclar Vivadent) was used to create build-ups. After 24 hours, the microtensile bond strength was measured (EZ Test, Shimadzu Co.). The failure mode was determined by light microscopy and scanning electron microscopy. One-way analysis of variance with the Bonferroni correction was used to analyze the data (P < .05). ResultsThe bond strength of the water-washed dentin surfaces in the calcium silicate-based sealer groups did not differ significantly from those of the control surfaces but the PA-pretreated surfaces exhibited relatively low-bond strength. The AH Plus-treated group had lower bond strength than the control group when no PA treatment was applied, but PA treatment restored the bond strength. The adhesive failure mode was most frequently found in the AH Plus group without PA etching. ConclusionsWhen a water-soluble calcium silicate-based sealer is used, sufficient bond strength can be obtained by washing with water alone, with no need for PA use.

Indications for the use of direct composite restorations in the management of tooth wear.

The increasing prevalence of tooth surface loss has been widely reported. Patients present with varying degrees of tooth wear and consideration is given to whether a prevention and monitoring approach, or a treatment and restoration approach, is appropriate. A missed diagnosis or excessively prolonged monitoring risks progression to the detriment of a successful outcome, with the potential compromise on the quality and quantity of tooth structure available for predictable adhesive dentistry. Direct composite resin (DCR) restorations can be considered as a viable treatment option for all extents of tooth wear, including cases that have progressed to a severe degree. This paper aims to review the indications for DCR restorations in the management of tooth wear, using clinical cases to demonstrate their effectiveness.

Time-and cost-effective 3-dimensional-printing workflow to rehabilitate worn dentitions: A clinical report

Current restorative methods of restoring worn or eroded dentition present drawbacks that may deter dentists or patients from pursuing complete mouth rehabilitation. A novel additive manufacturing approach using 3D printed definitive composite resin restorations is described as a less technique-sensitive and more cost-effective alternative. These restorations are straightforward to repair, modify, or replace.

Treatment of tetracycline-stained teeth: A narrative review

Tetracycline teeth are caused by the use of tetracycline antibiotics during the growth period, and the clinical manifestation is tooth staining. Aesthetic restoration can be carried out by bleaching, cold light whitening, all ceramic veneer restoration, all ceramic crown restoration, and light cured resin restoration. In the current research, researchers focus on new veneers and resin materials, and whether other tetracycline antibiotics induce tetracycline teeth or not.

Are universal adhesives in etch-and-rinse mode better than old 2-step etch-and-rinse adhesives? One-year evaluation of bonding properties to dentin

ObjectivesThis study compared the bonding properties of dentin of three 2-step etch-and-rinse adhesives (2-ERAs) to those of three universal adhesives (UAs) applied with an etch-and-rinse strategy (ER), immediately and after 1 year of water storage. MethodsSixty caries-free molars were divided into 6 groups according to the adhesive systems used (n = 10). The 2-ERA systems included were: 1) Adper Single Bond 2 (SB), 2) Tetric N-Bond (TB), and 3) Ambar (AM); and the UAs systems were: 4) Single Bond Universal (SBU) 5) Tetric N-Bond Universal (TBU), and 6) Ambar Universal (AMU). The occlusal third of each tooth was removed and the adhesives were applied. After the composite build-up, specimens were sectioned and tested for microtensile bond strength (µTBS) and nanoleakage (NL) immediately and after 1 year of water storage. In situ degree of conversion (DC) was only evaluated in the immediate time. For water sorption (WS), solubility (SO), and mass change (MC) tests, 48 disk-shaped specimens were prepared (n = 8) and assessed according to ISO 4049:2009. ResultsUAs showed higher µTBS and lower NL values than 2-ERAs did after 1 year of water storage (p = 0.001). Regarding DC, 2-ERAs showed higher DC values than UAs (p = 0.001). Regarding WS, 2-ERAs showed higher WS values than those of UAs (p = 0.00001), except for AM and AMU. Lower WS was observed for AM than for other 2-ERAs (p = 0.00001). ConclusionThe use of UAs applied with the ER strategy seems to be a more effective technique for maintaining adhesion to dentin substrate than 2-ERAS. Clinical significanceThis study may support clinicians in selecting the most adequate adhesive system to be used in ER strategy in dentin, demonstrating that UAs were more effective, considering the longevity of the resin restorations.

Fracture Load of Mesio–Occluso–Distal Composite Restorations Performed with Different Reinforcement Techniques: An In Vitro Study

Mesio-occluso-distal (MOD) cavity preparations are often fragile due to the amount of tooth and carious structure removed. MOD cavities can often fracture if left unsupported. The study investigated the maximum fracture load of mesi-occluso-distal cavities restored using direct composite resin restorations with various reinforcement techniques. Seventy-two freshly extracted, intact human posterior teeth were disinfected, checked, and prepared according to predetermined standards for mesio-occluso-distal cavity design (MOD). The teeth were assigned randomly into six groups. The first group was the control group restored conventionally with a nanohybrid composite resin (Group I). The other five groups were restored with a nanohybrid composite resin reinforced with different techniques: the ACTIVA BioACTIVE-Restorative and -Liner as a dentin substitute and layered with a nanohybrid composite (Group II); the everX Posterior composite resin layered with a nanohybrid composite (Group III); polyethylene fibers called "Ribbond" placed on both axial walls and the floor of the cavity, and layered with a nanohybrid composite (Group IV); polyethylene fibers placed on both axial walls and the floor of the cavity, and layered with the ACTIVA BioACTIVE-Restorative and -Liner as a dentin substitute and nanohybrid composite (Group V); and polyethylene fibers placed on both axial walls and the floor of the cavity and layered with the everX posterior composite resin and nanohybrid composite (Group VI). All teeth were subjected to thermocycling to simulate the oral environment. The maximum load was measured using a universal testing machine. The highest maximum load was exhibited by Group III with the everX posterior composite resin, followed by Group IV, Group VI, Group I, Group II, and Group V. A statistically significant difference was demonstrated between groups (p = 0.0023). When adjusting for multiple comparisons, there were statistical differences specific to comparisons between Group III versus I, Group III versus II, Group IV versus II, and Group V versus III. Within the limitations of the current study, it can be concluded that a higher maximum load resistance can be achieved (statistically significant) when reinforcing nanohybrid composite resin MOD restorations with everX Posterior.

Comparative Evaluation of Microleakage of Different Class V Cavity Preparation Restored with Composite in Primary Molars: An In Vitro Study

To compare the effect of the cavity design and the location of the gingival wall, onenamel and cementum on the microleakage of Class V composite resin restorations in primary molars.

A digital protocol for the fabrication of anatomic-contour implant zirconia crowns directly screwed on external hexagonal implant connections without the interposition of a Ti-base component

A straightforward and effective restorative option is proposed for implant-supported fixed prostheses with external connections by using monolithic zirconia without the interposition of a Ti-base component. The technique is based on a modification of the Brånemark connection used to link metal-ceramic or metal-composite resin restorations directly to the implant.

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.

Amalgam x Composite Resin: supplies and restorative procedures more performed among Oral Health Teams in Brazil

Abstract This study aimed to compare the availability of supplies and amalgam and composite resin restorations among Oral Health Teams (OHT) in Brazilian regions. Secondary data were extracted from Modules I and II of the 1st (2012) and V and VI of the 2nd (2014) and 3rd cycle (2017) of the external evaluation of the National Program for Access and Quality in Primary Care2. The proportions between regions and cycles were compared using the Chi-square test with the z-test adjusted by the Bonferroni method (p&lt;0.05). Among 2012, 2014, and 2017 there was a significant reduction in the proportion of OHT that performed amalgam restorations (87.5%, 89.2%, and 80.2%; p&lt;0.001) and an increase in resin composite (92.5 %, 97.7%, and 99.0%; p&lt;0.001), with the same trend in Brazilian regions (p&lt;0.001). Amalgamator availability decreased among 2012 (99.0%), 2014 (98.4%) and 2017 (85.6%) (p&lt;0.001). Amalgam availability was lower in 2017 (80.1%), compared to 2012 (87.5%) and 2014 (97.5%) (p&lt;0.001). The availability of light curing decreased between 2012 (99.0%), 2014 (98.4%) and 2017 (85.6%) (p&lt;0.001), being less available in the North (95.7%) (p&lt;0.001). The light-curing resin increased between 2012 (94.1%), 2014 (96.6%) and 2017 (97.0%) (p&lt;0.001), with no increase only in the North (p=0.134). While there was a reduction in supplies and amalgam restoration, there was an increase in supplies and resin composite restorations in the period evaluated in all Brazilian regions. However, regional disparities are still evident, with fewer supplies of restorative services in the North region.

The Different Polishing Systems Effect on Ormocer and Supranano Spherical Filler Composite Resin Surface Roughness

Background: The polishing procedure is an essential step in composite resin restoration. There are two types of polishing systems, which are one-step and multi-step polishing systems. Purpose: This study aimed to identify the effect of different polishing systems on the surface roughness of ormocer and supranano spherical filler composite resin. Material and Methods: This study was conducted in an experimental laboratory. The specimens were ormocer and supranano spherical filler composite resin filled in a cylindric metal mold. The total of specimens was thirty-two (n=32) of each composite resin. Each composite resin specimen was divided into four groups, then polished using PoGo (group 1 – one-step polishing system), Optrapol (group 2 – one-step polishing system), Sof-lex (group 3 – multistep polishing system), and Optidisc (group 4 – multistep polishing system). Specimens were incubated at 37℃ for 24 hours. Subsequently, specimens were assessed with a stylus profilometer surfcorder SE 1700. Data were analyzed using an independent t-test and one-way ANOVA. Result: There was a significant difference in surface roughness of the one-step and multistep groups (p ≤ 0.05). The lowest surface roughness value was in the Sof-Lex disc group (0.4026μm), and the highest surface roughness was in the PoGo group (1.1036μm). Conclusion: Based on composite resin, supranano spherical filler had less surface roughness than ormocer (p ≤ 0.05). Furthermore, both ormocer and supranano spherical filler polished using a multistep polishing system had lower surface roughness than those polished using a one-step polishing system.

Conservative Restorative Management of External Cervical Tooth Resorption: A Case Report

Background: External cervical resorption (ECR) is one of the subclassifications of external root resorption. The etiology of ECR is still unclear. In most cases, it is not evident and asymptomatic before the involvement of the pulp. Case presentation: This paper reports a case of ECR in the mandibular right first molar of a 24-year-old patient who presented with an asymptomatic pink tooth. A two-dimensional radiograph and Cone beam computed tomography (CBCT) showed cervical resorption penetrating at the cementoenamel junction level from the mesio-lingual aspect. It approximates the pulp horn coronally within the lingual dentinal wall. Discussion: The treatment of the case involved debridement of the resorptive defect and Mineral Trioxide Aggregate (MTA) was applied as a direct pulp capping, glass ionomer as a base, and the tooth was restored using composite resin restoration. After 6-months of follow-up, the radiographic examination showed healthy bone and periodontal structures with no evidence of periapical pathology. Conclusion: ECR is an aggressive and invasive lesion that acts silently, requiring early diagnosis and treatment for a successful outcome. The lesion size, location, and accessibility are the main factors affecting the successful treatment of ECR.

Effect of Air Abrasion on Delayed Dentin Sealing Post-operative Sensitivity for Indirect Resin Composite Restorations

BACKGROUND: There are several treatment options available to reduce the post-operative sensitivity (POS) of indirect resin composite restorations. AIM: This study was to evaluate the effect of air abrasion on delayed dentin sealing POS for indirect resin composite restorations. MATERIALS AND METHODS: Twenty-eight patients between the ages of 18 and 30 were enrolled and randomly assigned to one of two treatment groups, with 14 teeth (n = 14) in each group. Following the collection of baseline pre- operative data, the diagnosis of caries was made based on the clinical examination and radiographic examination, and all cavities were prepared. Group one (G1) prepared cavities were exposed to airborne particles before the selective etch technique was used without the use of cementation, and the selective etch technique was used. In the second group (G2), air abrasion during cementation. The visual analog scale was used to evaluate POS at baseline, 1 day after cavity preparation (T1), 1 week after indirect composite restoration cementation (T2), 3 months (T3), and 12 months (T4). STATISTICAL ANALYSIS USED: The one-sample Kolmogorov–Smirnov test was used to assess the normality of distribution parameters first, and then, for non-parametric distributions, the Kruskal–Wallis test was used to assess the interaction between different variables. The Mann–Whitney U-test was then used to compare the two groups. RESULTS: Despite air abrasion’s effect, there was no statistically significant change in scores between the G1 and G2 groups. POS was highest at T1, then T2, T3, and T4. Statistically, these differences were significant (p = 0.001). No statistically significant differences (p &gt; 0.05) were found between T2, T3, and T4 with or without air abrasion. CONCLUSION: The delayed dentin sealing POS is unaffected by air abrasion during indirect resin restorations’ cementation.

Effect of Immediate Dentin Sealing with Air Abrasion on Post-operative Sensitivity for Indirect Resin Composite Restorations

Background: Various treatment modalities are available to decrease the postoperative sensitivity of indirect resin composite restorations.&#x0D; Aim: Compare the effectiveness of immediate dentin sealing using universal adhesive and air abrasion versus immediate dentin sealing without air abrasion on postoperative sensitivity in teeth prepared for indirect resin composite restorations.&#x0D; Methods and Materials: Twenty-eight patients between 18 and 30 years of age were recruited and randomized to two treatment protocols with fourteen teeth (n = 14) included in each protocol. After baseline preoperative data collection, the diagnosis of caries was made depending on the clinical examination and radiographic examination. After cavity preparation was done, all cavities in each protocol were managed with immediate dentin sealing, and the single-bond universal adhesive was applied over all the dentinal surfaces according to the manufacturer’s instructions. Protocol One (P1) air abrasion was used for immediate dentin sealing before cementation. In the second protocol (P2), the dentin was sealed without the use of air abrasion. Postoperative sensitivity (POS) was evaluated using the Visual Analog Scale (VAS) at baseline, one day after the cavity preparation (T1), one-week post-cementation of the indirect composite restoration (T2), after 3 months (T3), and after 12 months (T4).&#x0D; Statistical analysis used: The normality of distribution parameters was evaluated by one-sample Kolmogorov-Smirnov first, and then, for nonparametric distribution, the Kruskal-Wallis Test was used to test the interaction between different variables. followed by the Mann-Whitney U test to compare the two groups.&#x0D; Results: Despite air abrasion's effect, there was no statistically significant change in scores between the P1 and P2 groups. Postoperative sensitivity was highest at T1, then T2, T3, and T4. Statistically, these differences were significant (P 0.001). No statistically significant differences (P &gt; 0.05) were found between T2, T3, and T4 with or without air abrasion.&#x0D; Conclusion: Air abrasion during cementation of indirect resin restorations does not affect postoperative sensitivity after immediate dentin sealing.&#x0D; Keywords: Immediate dentin sealing, Air abrasion, surface treatment, Visual Analog Scale (VAS), Postoperative sensitivity.&#x0D; Key Messages: Air abrasion applied to immediate dentin sealing can be used safely without affecting postoperative sensitivity.

Novel antibacterial and apatite forming restorative composite resin incorporated with hydrated calcium silicate

BackgroundWhite Portland cement is a calcium silicate material. It exhibits antibacterial properties and is biocompatible. In addition, calcium silicate-based materials are known to release calcium ions and form apatite. The purpose of this study was to develop a novel bioactive restorative resin composite with antibacterial and apatite forming properties to prevent tooth caries at the interface of teeth and restorative materials, by incorporation of hydrated calcium silicate (hCS) derived from white Portland cement.MethodsTo prepare the experimental composite resins, a 30 wt% light-curable resin matrix and 70 wt% filler, which was mixed with hCS and silanized glass powder were prepared in following concentrations: 0, 17.5, 35.0, and 52.5 wt% hCS filler. The depth of cure, flexural strength, water sorption, solubility, and antibacterial effect were tested. After immersion in artificial saliva solution for 15, 30, 60, and 90 days, ion concentration by ICP-MS and apatite formation using SEM-EDS, Raman spectroscopy and XRD from experimental specimens were analyzed.ResultsAll experimental groups showed clinically acceptable depths of cure and flexural strength for the use as the restorative composite resin. Water sorption, solubility, released Ca and Si ions increased with the addition of hCS to the experimental composite resin. Experimental groups containing hCS showed greater antibacterial effects compared with the 0 wt% hCS filler group (p < 0.05). The 52.5 wt% hCS filler group produced precipitates mainly composed of Ca and P detected as hydroxyapatite after immersion in artificial saliva solution for 30, 60, and 90 days.ConclusionsThis results show that composite resins containing hCS filler is effective in antibacterial effects. hCS has also apatite formation ability for reducing gap size of microleakage by accumulating hydroxyapatite precipitates at the restoration-tooth interface. Therefore, novel composite resin containing hCS is promising bioactive resin because of its clinically acceptable physiochemical properties, antibacterial properties, and self-sealing potential for prevention of microleakage for longer usage of restorations.

Dexamethasone-doped nanoparticles improve mineralization, crystallinity and collagen structure of human dentin

ObjectivesBioactive materials have been used for functionalization of adhesives to promote dentin remineralization. This study aims to evaluate bonding ability and both mechanical and chemical behavior of demineralized dentin infiltrated with polymeric nanoparticles doped with dexamethasone (Dex-NPs). MethodsDentin conditioned surfaces were infiltrated with NPs, Dex-NPs or Dex-Zn-NPs. Bonded interfaces were also created and stored for 24 h or 21d, and then submitted to microtensile bond strength testing. Dentin remineralization was analyzed by Nanohardness, Young's modulus and Raman analysis. ResultsAt 21d of storage, dentin treated with undoped-NPs attained the lowest nanohardness and Young's modulus. Dex-NPs and Zn-Dex-NPs increased dentin nanohardness and Young's modulus after 21d Raman analysis showed high remineralization, crystallinity, crosslinking and better structure of collagen when functionalized Dex-NPs were present at the dentin interface. ConclusionsInfiltration of dentin with Dex-NPs promoted functional remineralization as proved by nanomechanical and morpho-chemical evaluation tests. Dexamethasone in dentin facilitated crystallographic maturity, crystallinity and improved maturity and secondary structure of dentin collagen. Clinical significanceUsing dexamethasone-functionalized NPs before resin infiltration is a clear option to obtain dentin remineralization, as these NPs produce the reinforcement of the dentin structure, which will lead to the improvement of the longevity of resin restorations.

Fragment reattachment or direct restoration? An in vitro study.

The fracture resistance of teeth subjected to fragment reattachment may improve when the technique is performed using intermediate materials. The aim of this study was to evaluate the influence of different bonding materials, including pre-heated composite resin, on the fracture resistance of teeth subjected to the reattachment technique compared with a direct composite resin restoration. After simulating a tooth fracture, each specimen was reattached by using one of the following intermediate materials (n=15): G0, negative control (sound teeth); G1, Z100; G2, pre-heated Z100; G3, Filtek Z350 XT; G4, pre-heated Filtek Z350 XT; G5, Filtek Z350 XT Flow; and G6, RelyX Veneer. In G7, direct class IV restorations were performed using Filtek Z350 XT composite resin. The fracture resistance was evaluated using a universal testing machine under a compressive load of 1 mm/min. One-way analysis of variance (ANOVA) and the post hoc Tukey test (5%) were conducted. G0 showed the highest fracture resistance, and this was statistically different from the other experimental groups (p < .05) except for G2 and G4, in which the fragments were bonded using pre-heated resins. A statistically significant difference was found between groups G1 and G6 (one-way ANOVA, p=.04). For G1 and G2, a significant difference was found between bonding with and without pre-heating (p < .05). This difference was not observed in G3 and G4 (p > .05). No statistically significant difference was found between the reattached and directly restored groups (t-test, p=.53). The tooth reattachment technique using pre-heated composite resin showed fracture resistance values similar to those of the sound tooth group. No difference was found between the fragment reattachment and direct composite resin techniques.

Digital technology for fluid resin injection to close anterior diastema after orthodontic treatment.

Anterior diastema and tooth defects are common clinical issues in restorative dentistry and are often restored by veneers or crowns based on the results of digital smile design and wax-up. Traditional direct resin restoration for closing a diastema is relatively minimally invasive but is time consuming and laborious, and shape control depends on experience. Digital technology can be used to design and transfer the shape of aesthetic restoration more accurately and quickly; thus, it could close anterior diastema and restore defects easily. According to the workflow, this technical process integrates virtual design and practical wax-up, transfers the designed restoration shape by templates, and injects through the preset channel after the template is in place. This clinical technique simplifies the clinical operation and saves clinical time, which can effectively improve the predictability and accuracy of the restoration and reduce technical sensitivity. This digital workflow provides a new technology for closing diastema quickly and effectively.

The efficacy of lining materials in the reduction of microleakage in class II composite resin restoration using the sandwich technique: A stereomicroscopic study.

The sealing ability of different liners under composite restorations in the reduction of microleakage. To evaluate the effects of three different liners in sandwich techniques on gingival microleakage of class II composite restorations. Standardized Class II box cavities were prepared on forty premolar teeth and randomly divided into four groups, n = 10: Group A, no liner (control); Group B, Polofil NHT Flow; Group C, Ionolux; and Group D, Fuji VII. The etching, bonding, and process for restoring the whole remaining mass of the cavities with G-aenial composite were the same, with the sandwich material expectations. Dye penetration was evaluated using a stereomicroscope. Duncan's Post hoc analysis and Friedman's test. Group A showed the highest microleakage followed by Group D, Group C, and Group B. Polofil NHT Flow seems to be a promising liner for gingivally deep class II cavities.