Total-etch System Research Articles

Comparative Evaluation of Orthodontic Bonding Systems for Ceramic Brackets on Zirconia Crowns: A Shear Bond Strength and Adhesive Remnant Index Study

Background The purpose of this research was to compare the adhesive residual score/adhesive remnant index (ARI) and shear bond endurance between the two orthodontic bonding systems for zirconia surface bonding: Self-etch (Scotchbond Universal) and total-etch (Transbond XT). Materials and Methods Color-coded acrylic blocks embedded with zirconia slabs were prepared, and the orthodontic brackets (ceramic) were bonded using either the total-etch or self-etch system. Group 1, represented by pink-colored blocks ( N = 12), accommodated 12 zirconia surfaces using the total-etch system, while Group 2, represented purple-colored blocks ( N = 12), also housed zirconia surfaces using the self-etch system. The shear bond strength was evaluated using an Instron Universal Testing Machine, and ARI scoring was done upon debonding. The statistical software SPSS was used for the analyses. Results The average bonding strength for the Scotchbond Universal etch system was 6.21 ± 0.76 MPa, while for the total-etch system, it was 5.59 ± 1.37 MPa. The ARI scores revealed that 83% of surfaces bonded with the self-etch system had no adhesive residue (ARI score 0), compared to 66% for the total-etch system. Conclusion The self-etch bonding agent demonstrated superior bond strength (6.2 MPa) compared to the total-etch system (5.6 MPa). Furthermore, it exhibited better ARI scores, indicating minimal adhesive residue. These findings suggest that the self-etch system is preferable for bonding ceramic brackets to zirconia crowns, offering improved bonding efficacy and ease of clean-up.

Assessment of Bond Strength of Different Bonding Systems to Eroded Dentin Using Sonic Activation: In Vitro Study

Abstract Objective Bonding to dentin is a great challenge, and erosion makes it difficult. This study evaluated the effect of sonic agitation on bond strength to eroded dentin using total etch (TE) and self-etch (SE) adhesive systems. Material and Methods A 96-sound human maxillary premolar teeth were prepared to obtain a flat dentin surface, randomly divided into two groups of 48 teeth each. One group was erosive demineralized with 0.05-M citric acid solution to produce an erodedlike dentin surface using de- and remineralization cycles, and the other group was considered a control with no erosive treatment. Each group was bonded with two different bonding strategies, TE (Single Bond 2) and SE (AdheSE One F). Each bonding system was applied with and without sonic activation, and the effect of bond agitation on shear bond strength (SBS) was tested after the application of composite to bonded dentin surface under shear load (0.5 mm/min). Two samples from each group were randomly selected for scanning electron microscopy (SEM) evaluation of the hybrid layer quality. An independent sample t-test was used to assess the effect of erosion, activation, and adhesive type on the SBS. Statistical significance was set at p < 0.05. Result Concerning dentin substrate type, eroded dentin has lower SBS mean values than sound dentin, although it was not significant. Regarding the bonding strategy, TE produced higher SBS values than the SE bonding strategy; it was significant only in sound dentin; despite the bonding strategy and the substrate dentin type, sonic activation produced a significant rise in SBS values except when the SE bonding strategy was applied to eroded dentin where the rise was of no significant value (p > 0.05). Conclusion Sonic agitation effectively improves the SBS value of composite bonded to eroded and sound dentin in both TE and SE strategies.

Comparative Evaluation of the Bonding Efficacy of Multimode Adhesive, Two-Step Self-Etch Adhesive, and a Total-Etch System to Pulpal Floor Dentin - An In vitro Study.

Postendodontic restoration with composite resins has gained popularity due to the development of more reliable adhesives with simplified bonding procedures and less technique sensitivity. Pulpal floor dentin is a complex biological structure and a more challenging bonding substrate. Hence, appropriate selection of the bonding agent for these regions of the tooth is important. To compare the shear bond strength of a new generation of dental adhesives referred to as multimode adhesives, two-step self-etch adhesive, and a total-etch system to pulpal floor dentin. Sixty human mandibular molars were sectioned with a slow speed diamond disc to expose the pulp chamber and divided into four groups of 15 teeth each, based on the bonding agent used. Group A: Single bond universal (self-etch); Group B: Single Bond Universal (etch-and-rinse), Group C: Clearfil SE Bond, Group D: Adper Single Bond 2. Using a split Teflon mold, composite cylinders were built on the prepared dentinal surfaces. The shear bond strength was then evaluated with the universal testing machine. Two step self-etch adhesives recorded higher shear bond strength than total-etch and multimode/universal adhesives applied in both self-etch and etch-and-rinse techniques. The self-etching/priming system bonded more strongly to the pulpal floor dentin than multimode adhesive and total-etch system.

An overview of dentin conditioning and its effect on bond strength

Given the inherent qualities of this medium, particularly when contrasted to enamel bonding, bonding to dentin is considered to be a less dependable approach. Further, when dentin is reduced, a sizable amount of cutting detritus coats the dentin's exterior, forming the smear layer. A steep decrease in interfacial adhesion over time has been attributed to the collagen web's inadequate resin impregnation as a result of the dentinal surface preparation with strong acidic agents like phosphoric acid, which left a zone of vulnerable collagen at the root of the hybrid smear layer. Self-etching priming agents that comprise acidic, non-cleansing, polymerizing monomers cause demineralization of the surface and encapsulate the collagen fibers and hydroxyapatite crystals while dissolving the smear layer or incorporating it into the adhesion interface. The concurrent occurrence of dentinal demineralization and monomeric penetration prevents collagen from buckling and shields an exposed collagen web. There may be a drawback to including the smear layer in the hybrid layer, according to certain investigations. Adhesion issues could arise even though the smear layer is reinforced with impregnated resin. To achieve dependable, robust resin-dentin connections, such defects may need to be removed by integrating a distinct etching process because they can reduce the resistance and longevity of the conjugated smear layer. In relation to a traditional bonding system, is has been discovered that removing the smear layer with 0.5 M ethylene diamine tetra-acetic acid (EDTA) before applying a self-etching primer result in greater bond strengths. Even though this approach integrates the smear layer within the adhesion interface, the pre-conditioning of dentin with just an acidic primer is highly convincing and merits additional exploration for the streamlined total-etching systems.

Evaluation of Self-Adhering Flowable Composites on Repeated Bracket Bonding Process: An In Vitro Study

Duration of orthodontic treatment becomes major concern. The present study compared shear bond strength (SBS) and adhesive remnant index (ARI) values of different adhesive systems with different application methods on rebonding process of retrieved orthodontic brackets. Eighty premolar teeth were equally divided into five groups. Transbond XT (TXT) which belongs to total-etch system was used in Group 1 as the control group. Nova Compo-SF (NC) and Vertise Flow (VF) (Kerr Dental, Italy) which are self-adhering flowable composites were used in Group 2 (NC+etch) and Group 3 (VF+etch) respectively with additional etching before application. Group 4 (NC) and Group 5 (VF) were used by following instructions of each brand. The brackets were debonded with a bracket removing plier and rebonded with the same procedures after sandblasting of the bracket and surface cleaning of the enamel. SBS and ARI were measured for each sample. Comparison between all groups was performed by Kruskal-Wallis test and chisquare test. The highest SBS was observed in NC+etch (median = 11.44, mean = 13.49±9.42), followed by NC (median = 10.17, mean = 11.35±6.55), TXT (median = 6.36, mean = 8.06±6.33), VF+etch (median = 5.68, mean = 6.75±4.58), and VF (median = 2.62, mean = 2.92±2.57), respectively. ARI 1 was observed in 81.3% of TXT whereas 62.5% of NC+etch. ARI 1, 2, and 3 were equally distributed in VF+etch group (31.3%). ARI 5 was observed in 37.5% of NC and 62.5% of VF. Analyses referred to statistically significant differences between five groups regarding both SBS and ARI (p < 0.001). As NC showed the highest SBS on rebonding process, it can be a promising alternative to TXT which is the gold standard.

Iontophoresis effects of two-step self-etch and total-etch systems on dentin permeability and sealing of composite restoration under simulated pulpal pressure.

Studies demonstrated the bond strength enhancement and the decrease in degradation of the adhesive interface after applying either self-etch adhesives or two-step, etch-and-rinse adhesives under an electric field. However, the presence of dentinal fluid driven by the pulpal pressure in vivo is a profounding factor affecting both the sealing ability and bond strength of adhesives. This study aimed to evaluate the effect of three-step etch-and-rinse and two-step self-etch adhesives when applied with iontophoresis under simulated pulpal pressure on the permeability of dentin, resin infiltration, and the sealing ability of resin composite. The experiments were done on 32 recently extracted premolars, randomly assigned into four groups (n = 8) according to two adhesive systems (SBMP and SE), applied following the manufacturer's instructions (control) for two groups or with iontophoresis for the others (SBMPi and SEi). For the iontophoresis, the anodal current was applied at 75μA for 20s through the cavity electrode during the bond. The fluid flow rate of dentin was recorded after cavity preparation (smear-layer-covered dentin; T1), bonding (T2), and composite restoration (T3) during the maintained pulpal pressure of 20mmHg. The flow rates were expressed as a percentage relative to the initial smear-layer-covered value for each specimen. Results were analyzed using repeated measures ANOVA. Scanning electron microscopy (SEM) was performed to observe the resin/dentin interface. There were no significant increases in the mean flow rates from T1 to T3 in the SBMP (P = 0.355), while these changes in the SE were significant between T1 (100%) and T2 (166.77%) and T1 and T3 (221.16%) (P = 0.002; one-way RM ANOVA; Holm-Sidak test). For the iontophoresis groups, the mean flow rates decreased significantly from T1 to T2 and T1 to T3 of both SBMPi (T2 = 86.43, and T3 = 79.53; P < 0.001) and SEi groups (T2 = 87.96, and T3 = 81.48; P = 0.004). The iontophoresis of both adhesives produced the optimal resin infiltration with improved quality of the hybrid layer and resin tags. SBMP bonded with or without iontophoresis performed better sealing ability than SE under the same condition. Both adhesives applied with anodal iontophoresis significantly decreased the dentin permeability, contributing to the improved resin infiltration.

Clinical in-situ evaluation of the effect of rubber dam isolation on bond strength to enamel.

To evaluate the effect of rubber dam isolation on shear bond strength of two different adhesive systems to enamel. The mesial, distal, lingual, and vestibular enamel surfaces of thirty human third molars were prepared (total n= 120). A custom splint was made to fit a volunteer's maxilla, holding the specimens in place in the oral cavity. Four composite resin cylinders were bonded to each tooth with one of two bonding agents (OptiBond FL and Prime&Bond active) with or without rubber dam isolation. Shear bond strength was tested in a universal testing machine and failure modes were assessed. Significance level for statistical analyses was set at 5%. All pairwise comparisons revealed statistical differences (p< 0.05). The highest mean shear bond strength values were obtained in rubber dam experimental groups, regardless of the adhesive system. Group OptiBond FL with rubber dam presented the highest mean bond strength values. Fracture modes for specimens bonded without rubber dam isolation were adhesive and cohesive within enamel, while rubber dam experimental groups revealed only cohesive fractures. Absolute isolation with rubber dam increases bond strength to enamel, independent of the adhesive system. The three-step total-etch system OptiBond FL provided significantly higher bond strength values than Prime&Bond active under both experimental conditions. Rubber dam isolation has a significant effect on bond strengths to enamel, independent of the adhesive system. Its application is, therefore, advised whenever adhesive procedures are performed. A filled three-step etch-and-rinse adhesive performed superiorly, with or without rubber dam isolation, when bonding to enamel compared to an isopropanol-based universal adhesive.

Phosphoric acid containing proanthocyanidin enhances bond stability of resin/dentin interface.

Proanthocyanidin (PA) is a promising dentin biomodifier due to its ability to stabilize collagen fibrils against degradation by matrix metalloproteinases (MMPs); however, the most effective protocol to incorporate PA into bonding procedures is still unclear. This study evaluated the effect of dentin biomodification with a PA acid etchant on MMP activity, adhesive interface morphology and resin-dentin microtensile bond strength. Sound extracted human molars were flattened to expose dentin and acid-etched for 15 s according to the groups: EXP - experimental phosphoric acid; EXP+PA - experimental phosphoric acid 10% PA; TE - total-etching system; SE - self-etching system. Samples were restored with composite resin and stored in distilled water (37ºC). MMP activity and interface morphology were analyzed after 24 h by in situ zymography (n=6) and scanning electron microscopy (n=3), respectively. The resin-dentin microtensile bond strength (μTBS) was evaluated after 24 h and 6 months storage (n=6). Significantly higher MMP activity was detected in etched dentin compared with untreated dentin (p<0.05), but no difference among acid groups was found. Resin tags and microtags, indicative of proper adhesive system penetration in dentinal tubules and microtubules, were observed along the hybrid layer in all groups. There was no difference in μTBS between 24 h and 6 months for EXP+PA; moreover, it showed higher long-term μTBS compared with TE and EXP (p<0.05). The results suggest that 15 s of biomodification was not sufficient to significantly reduce MMP activity; nonetheless, EXP+PA was still able to improve resin-dentin bond stability compared with total- and self-etching commercial systems.

Effects of C-factor on dentin bonding using various adhesive systems.

This study evaluated the effect of C-factor on the bond strength of a resin composite to floor and wall dentin using various adhesive systems. Four dentin substrates (flat wall, flat floor, cavity wall, or cavity floor) were prepared on human molars. Each specimen was restored with one of three adhesives; Clearfil SE Bond, Single Bond, or Clearfil tri-S Bond followed by buildup or filling using Z100 resin composite. The specimen was cut perpendicular to the bonded surface parallel to the floor or wall to obtain beams after light curing at 24,000 mJ/cm2. The microtensile bond strength to wall specimens or the cavity floor was determined. Data were analyzed. All adhesive systems exhibited the highest bond strength to flat wall group (p < 0.05). The bond strength to the cavity group was significantly lower than that to the respective flat group regardless of the bonding system (p < 0.05). There was no significant difference in bond strength with Clearfil SE Bond and Clearfil tri-S Bond between the cavity wall and cavity floor (p > 0.05). The findings suggested that the strength of bonding to the cavity floor and cavity wall was affected by C-factor regardless of the adhesive system. Bonding to flat wall was higher than flat floor regardless of the adhesive system. Self-etching system provided uniform bond to the cavity wall and cavity floor dentin. However, total etching system reduced bond to the cavity floor than to the cavity wall.

Investigation of the effect of simultaneous use of silver diamine fluoride and potassium iodide on the shear bond strength of total etch and universal adhesive systems to dentin.

Background:Applying silver diamine fluoride (SDF) is recommended to arrest and prevent dental caries. However, it may jeopardize the bond of the restorative materials to the tooth. The aim of the present in vitro study was to evaluate the effect of the simultaneous use of the SDF and potassium iodide (KI) on shear bond strength to the sound dentin.Materials and Methods:In this in vitro study, on the buccal and lingual surfaces of the 48 human third molar teeth, dentinal surfaces with a diameter of 6 mm were created by removing the enamel. Then, the specimens were divided into four groups based on applying or not applying the KI/SDF and adhesive type (etch and rinse [E and R] or universal adhesive). Afterward, cylindrical composite restoration was made on the surfaces. Half of the specimens were subjected to 1000 cycles of thermocycling. Subsequently, the shear bond strength was evaluated by Universal testing machine. Furthermore, the type of failure was determined by a stereomicroscope. Data were analyzed by t-test and Chi-square at a significance level of P < 0.05.Results:There were statistically significant differences in shear bond strength between Groups 1 and 3 (P < 0.05), whereas the bond strength difference between Groups 2 and 4 was not statistically significant (P = 0.609). Failures were predominantly of the mixed type in almost all groups.Conclusion:Based on the results of this study, the superiority of shear bond strength of universal adhesive to the sound dentin compared to E and R adhesive was confirmed. Thus, using this type of adhesive is recommended under the condition that KI/SDF anticaries material is applied.

A Contemporary Evaluation on Posterior Direct Restoration Teaching among Undergraduates in Dental Schools in Malaysia.

There is a current trend to restore posterior teeth with composite resin due to increasing demands on natural tooth colour restoration and increased concern about the safety of amalgam restorations. The objective was to evaluate the current teaching of posterior direct restoration among restorative dental lecturers in Malaysia compared to available international literature. An online questionnaire, which sought information on the teaching of posterior restoration was developed and distributed to 13 dental schools in Malaysia. The response rate for the questionnaire was 53.8%. The most popular posterior restoration teaching methods among the respondents were lecture (95.7%), demonstration (87.0%) and problem-based learning (PBL) (73.9%), while continuous assessment and a practical competency test (82.6%) were the most popular assessment methods. Placing a hard setting calcium hydroxide and GIC base for deep cavity restored by composite restoration was taught in 79.2% of cases. The standard protocols for posterior composite restoration were incremental filling in deep cavity (87.5%), using circumferential metal bands with wooden wedge (91.7%), with a total etch system (95.8%), using a light emitting diode (LED) light curing unit (91.7%), finishing using water cooling (80%) and finishing with a disc (87.5%). Graduates from dental schools in Malaysia received similar theoretical, preclinical and clinical teaching on posterior restoration techniques, although there were variations in the delivery methods, techniques and assessments, pointing to a need for uniformity and consensus.

Comparative Evaluation of Resin Dentin Interface using Universal and Total- Etch Adhesive Systems on Sound and Eroded Dentin: In Vitro Study.

Objective This study aimed to compare the resin-dentin interface of sound and eroded dentin using universal and total-etch adhesive systems. Materials and Methods Forty caries-free extracted human premolars were collected, and the occlusal surfaces were ground by using slow speed diamond disc with copious water supply until a flat superficial dentin was exposed. The test group underwent erosive cycle (n = 20), and another group (n = 20) was reserved for control group. Erosive protocol consisted of immersion in 1.23% citric acid for 1 minute every 12 hours and stored in artificial saliva. Both the control and eroded teeth were further subdivided (n = 10) for composite restoration by using either self-etch or total-etch systems. Then the tooth samples were sectioned longitudinally and observed under confocal laser scanning microscope at ×10 magnification to evaluate resin tag length and hybrid layer thickness. Statistical Analysis The data obtained were analyzed by using independent t-test. Results The highest mean value of the resin tag length and thickness of hybrid layer was observed with total-etch system in sound dentin group compared with other groups (p < 0.001). Conclusion The resin-dentin interface of sound dentin was found to be better than eroded dentin by using total-etch system. The resin-dentin interface of eroded dentin was superior to sound dentin by using self-etch adhesive system.

Comparing the Ability of Various Resin-Based Composites and Techniques to Seal Margins in Class-II Cavities.

Background: Resin-based composites (RBCs) provide excellent esthetics but the marginal micro-leakage in the proximal cavities remains a major concern. The aim of the present study was to assess the ability of various dental RBCs and techniques utilized for sealing deep dentin margin in class-II cavities. Methods: Box-cavities (class-II) on the distal and mesial surfaces of extracted (premolar) teeth were prepared with a gingival margin placed 1mm apical to the cemento-enamel junction. Teeth with prepared class II cavities were randomly divided into four study groups according to the type of restorative materials (conventional RBC; bulk-fill RBC; conventional RBC lined with flowable RBC and conventional RBC lined with resin-modified glass-ionomer-cement (GIC) as open sandwich-technique). Each group was further subdivided into a total-etch subgroup in which a separate etching step was performed before applying the bonding agent and a self-etch subgroup in which a self-etch adhesive system was used (n = 10). For each group, cavities were restored using the respective restorative materials and techniques, subjected to 1000 thermocycles, and placed in the methylene-blue dye. The specimen teeth were sectioned for further microscopic examination for micro-leakage. Results: The least dye penetration values were reported for group 4 (GIC) followed by the group Bulk-fill using the self-etch adhesive system (group 2b). The highest dye penetration was reported for the group Bulk-fill using the total-etch adhesive system (2a), followed by the group conventional RBC using the total-etch adhesive system). The total-etch adhesive system had significantly greater micro-leakage compared to the self-etch adhesive system (1a) (p = 0.026). Conclusions: The self-etch adhesive system significantly reduced the micro-leakage compared to the total-etch system. Bulk-fill RBC when bonded with the self-etch adhesive provided good marginal sealing ability comparable to open sandwich-technique using GIC.

Three-dimensional finite element analysis of resin-dentin interfaces bonded with total etching and self-etching systems under static tensile load

Three-dimensional finite element analysis of resin-dentin interfaces bonded with total etching and self-etching systems under static tensile load

Comparison Adhesive strength of Resin Composite between Total-etch and Self-etch Techniques on Enamel After Fluoride Application

Background : White Spot Lesion (WSL) is caused by Streptococcus Mutan which causes demineralization of teeth. One of the treatments of WSL is topical application of fluoride which aims to remineralize the teeth. However, if topical fluoride treatment does not give satisfactory results, alternative treatments can be made using restorative treatments, one of which is veneers. The procedure for applying veneers requires the application of an adhesive system. The adhesive system used to apply veneers is self-etch and total-etch. Several references state that the application of fluoride which aims to remineralize teeth can influence the adhesiv strength of the restorative material using self etch and total-etch techniques. Purpose : To determine the effect of composite resin adhesion strength between total-etch and self etch techniques on enamel after fluoride application. Review : Literature sources used in the preparation of the article through several databases with descriptions of the effects of fluoride application before total-etch and/or self etch administration. From the existing references, it was found that the application of fluoride before the total-etch system had a less significant effect on the adhesiv strength. Whereas in the self etch system, fluoride application has a significant effect on the adhesiv strength. Conclusion : More references say that the application of fluoride before the total-etch system has a better adhesive strength than the application of fluoride before the self etch system

Effect of total-etch and self-etch adhesives on the bond strength of composite to glass-ionomer cement/resin-modified glass-ionomer cement in the sandwich technique - A systematic review.

The success of the sandwich technique depends on the bond strength of composite to glass-ionomer cement (GIC)/resin-modified glass-ionomer cement (RMGIC). Currently used adhesives employ the total-etch and the self-etch techniques. The total-etch system is technique sensitive, whereas the self-etch system is popular for its ease of use. The aim of this systematic review is to compare the effect of total-etch and self-etch adhesives (SEAs) on the bond strength of composite to GIC/(RMGIC) in the sandwich technique. A literature search was conducted using electronic databases (PubMed, Web of Science, Ebscohost, and Scopus) limiting the year of publications from January 1, 2000, to September 30, 2018, to identify the relevant studies. All the cross-references of the selected studies were also screened. In vitro studies on extracted human teeth were selected. A total of 10 articles were included in this review. A conclusion was drawn that SEAs when used in the sandwich technique resulted in greater bond strength in comparison to total-etch adhesives. Moreover, increased bond strength was achieved when the primer was employed on unset GIC as compared to set GIC. Furthermore, the application of SEAs over uncured RMGIC (co-curing technique) resulted in better bond strengths as compared to their application over cured RMGIC.

Shear bond strength of the adhesive/dentin interface after different etching protocols.

Background:Lack of bond stability between the composite resin and dentin remains one of the main reasons for having to replace esthetic restorations.Aim:This study aimed to evaluate the influence of chlorhexidine (CHX) on the bond strength of a total etching system to dentin tissue after degradation of the adhesive interface.Materials and Methods:One hundred and eighty fragments of human molars were divided into three groups (n = 15) according to the materials used during the acid-etching step: Group 1 (control), 37% phosphoric acid; Group 2, a combined solution of 37% phosphoric acid and 2% CHX; and Group 3, 37% phosphoric acid followed by 2% CHX. Following the restorative procedures, the groups were divided into four subgroups according to the number of thermal cycles (TC) and to the time of storage in water (SW), and then subjected to a shear strength test, until fracture: (A) 0 TC/24-h SW; (B) 500 TC/1-week SW; (C) 2,000 TC/1-month SW; and (D) 12,000 TC/6-month SW. Two-way analysis of variance and Duncan's complementary test were used to perform multiple comparisons.Results:After the 24-h and 1-week SW time periods, no statistically significant difference was found among the shear strength values of the control and the experimental groups: 5.48 ± 0.59 MPa, 5.44 ± 0.56 MPa, and 5.65 ± 0.94 MPa for G1, G2, and G3, respectively. However, the shear strength values decreased significantly in all the study groups after 1 month, namely 3.60 ± 0.41 MPa, 3.08 ± 0.65 MPa, and 3.49 ± 0.23 MPa for G1, G2, and G3, respectively. After 6 months, similar results were found for G1 and G3, namely 2.77 ± 0.58 MPa and 1.74 ± 0.52 MPa, respectively, whereas the 0.77 ± 0.26 MPa value found for G2 was significantly lower than those found for the G1 and G3 groups. No differences were found between the groups with respect to fracture-type frequencies.Conclusion:The use of CHX as an agent to rehydrate the dentin had a negative influence on bond strength.

The Effect of Biodentine Maturation Time on Resin Bond Strength When Aged in Artificial Saliva.

Biodentine is a calcium silicate cement (CSC) that has been broadly applied in vital pulp therapy. The quality of the Biodentine-composite bond has a significant effect on the longevity of the definitive restoration. The aim of this study is to investigate the shear bond strength (SBS) between Biodentine and composite restoration at different maturation times of Biodentine aged in artificial saliva. Fifteen Biodentine discs were allocated into three groups (n = 5) based on the timeframe of performance of composite restoration: immediate (after 12 min), after 14 days, and after 28 days of Biodentine maturation. Total etch and rinse adhesive system and bulk-fill regular resin composite were used. The shear bond strength and the failure pattern were assessed. One-way ANOVA with the Bonferroni post hoc test was applied for statistical analysis at p < 0.05. The highest (32.47 ± 8.18 MPa) and the lowest (4.08 ± 0.81 MPa) SBS values were recorded for 14 days and 12 min groups, respectively. Significant statistical differences were reported among the groups, and a high statistically significant difference was found between the immediate group and the other groups. Adhesive failure patterns were evident in all groups. More clinically acceptable bond strength between the Biodentine and overlaid composite restoration is at 14 days after Biodentine maturation. Delaying the coverage of Biodentine later than 14 days may significantly reduce the SBS. Using the artificial saliva as an aging medium may affect the SBS between Biodentine and composite material.

Effect of different cement systems and aging on the bond strength of chairside CAD-CAM ceramics

Statement of problemThe bond strength of different chairside computer-aided design and computer-aided manufacturing (CAD-CAM) restorative materials to dentin with different resin cements needs to be evaluated. PurposeThe purpose of this in vitro study was to investigate the effect of 3 different cementation systems after thermal aging on the shear bond strength of different CAD-CAM materials. Material and methodsThe occlusal surfaces of 63 molar teeth of similar size were removed, and 21 zirconia-reinforced lithium disilicate (Vita Suprinity-VS), 21 polymer infiltrated ceramic (Vita Enamic-VE), and 21 resin nanoceramic (GC Cerasmart-GC) rectangular specimens of 2.5 mm in thickness were obtained. The ceramics were cemented using total etch (TE), self-etch (SE), and self-adhesive (SA) cement systems. Half of the specimens were subjected to thermal aging with 5000 cycles. The shear bond strength test of all the specimens was measured. Fractured ceramic surfaces were examined by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) analysis. The Shapiro-Wilk test, 3-way analysis of variance (ANOVA), and Fisher Least Significant Difference (LSD) tests were used to analyze the shear bond strength test data (α=.05). ResultsThe highest bond strength value was found in the nonthermal aged VS-TE and the lowest in the thermal aged VE-TE. Significant interaction was found between TE and SE cemented ceramics (P<.001). For specimens cemented with the SA system, significant interaction was found among ceramics with thermal aged specimens (P<.001). Thermal aging significantly decreased the mean bond strength (P<.05). ConclusionsDifferences in bond strength were observed in chairside CAD-CAM ceramics when cemented with TE, SE, and SA systems. Additionally, thermal aging significantly reduced the bond strength values of all the ceramic materials, regardless of the cementation procedure. Clinicians should consider these variables and choose the most suitable cementation systems for the material used.

Comparison of microleakage on Class V composite restoration: Study on total etch, self etch and selective etch technique

Background: A Class V restoration with composite resin poses a number of challenges, which can result in microleakage. Methods for minimizing microleakage include the use of adhesive materials and adhesive systems. Adhesive systems include total etch, self-etch, and selective etch. Each adhesive system has various advantages and disadvantages. Therefore, in a Class V cavity with little enamel attachment, research is needed to compare microleakage in total etch, self-etch, and selective etch systems to determine the best adhesion system to achieve treatment success. Objective: The purpose of this study was to compare total etch, self-etch, and selective etch adhesive systems in Class V composite resin restorations. Method: Class V cavities on premolar teeth (n = 24) were prepared on buccal and lingual surfaces. The teeth were divided into three groups: total etch, self-etch, and selective etch. All the samples of 3 mm mesiodistal, 2 mm occlusal–gingival, and 2 mm deep were prepared using a high-speed round bur. After the preparation of the samples, all the teeth were restored using a flowable composite resin. All the restored samples were immersed in 2% methylene blue for 24 h. They were then sectioned in a buccolingual direction and observed under a stereomicroscope at ×10 magnification. The data were analyzed using the Kruskal–Wallis test and post hoc Mann–Whitney U-test (P < 0.05). Result: There were significant differences in microleakage among the groups. The total etch group had the least microleakage, followed by the selective etch and self-etch groups. Conclusion: The use of phosphoric acid (37%) in total etch and selective etch technique reduced microleakage in composite restorations.