Self-etch Adhesive Systems Research Articles

Sonic application of one-step self-etch adhesive in composite restorations of non-carious cervical lesions: A double-blind randomized clinical trial.

To evaluate the influence of the sonic device on the clinical performance of one-step self-etch adhesive systems in non-carious cervical lesions (NCCLs) after 18 months. Forty patients participated in this study. Eighty restorations were assigned to two groups (n=40): Sonic application and Manual application. After the adhesive application (iBond Self-Etch, Kulzer, Hanau, Germany), NCCLs were restored using composite resin (Charisma, Kulzer, Hanau, Germany). The restorations were evaluated at baseline and after 18 months both according to the Word Dental Federation (FDI) and the United States Public Health Service (USPHS) criteria. Friedman repeated measures analysis of variance by rank and Wilcoxon test for significance in each pair were applied (α=0.05). After 18 months, 38 patients were evaluated. Twenty-three restorations were lost (19 for manual vs. 4 for sonic application). The retention rates (95% confidence interval) were 50% (CI 34.8%-65.1%) for manual application and 84.2% (CI 69.6%-92.6%) for sonic application (p < 0.05). Twelve restorations showed marginal staining (nine for manual vs. three for sonic application; FDI, p < 0.05) and nine some marginal discrepancy (seven for manual vs. two for sonic application; FDI, p < 0.05). No restorations showed postoperative sensitivity and caries recurrence at the time. The sonic application increases the retention rate of iBond Self-Etch after 18 months of clinical evaluation in NCCLs. The application of a simplified self-etch adhesive (iBond Self-Etch) associated to a sonic device seems to be an alternative to improve the clinical behavior in NCCLs.

Comparative analysis of wear resistant properties of materials used for direct restorations

Out of all the variety of materials available on the mar-ket to compensate for the lost hard tissues of teeth, the dentist in most cases prefers light-cured restoration ma-terials that meet both aesthetic and functional require-ments. The choice of material is highly dependent on each clinical case. The options for choosing a restoration material are characteristics similar to the properties of natural teeth, which would allow for high-quality resto-ration, and on the other hand, are able to minimize the violation of the edge fit. However, according to a number of studies, the probability of secondary caries after direct restoration of the hard tissues of the tooth, the cause of which is a violation of the marginal fit in the border area: enamel-composite, dentin-composite, is quite high. The purpose is to conduct a comparative analysis of materials used for direct restoration of teeth, capable of providing the most qualitative restoration of lost hard tissues of teeth. Materials and methods. Тhe study was carried out on 32 multi-root teeth of the lateral group of teeth of the upper and lower jaw. Different groups of resto-ration materials and adhesive systems were used as study materials. The simulation of thermocyclic loads of proto-types was carried out, followed by a fracture test using the Shimadzu AG-50kNXD machine. As a result of the study, diagrams were obtained showing the dependence of the stress applied to the test sample in MPa and the deformation resulting from the applied forces as a per-centage. Also, the results obtained reflect the calculation in all areas of the maximum applied force in Newtons and the maximum voltage in Mega Pascals. Research results.Тhe most resistant to mechanical stress were the samples, in the preparation of which the IV generation adhesive system OptiBond FL (Kerr) was used. The maximum value of the force that these samples were able to withstand was 353.27±4.80 N, and the value of the maximum volt-age was 28.11±0.38 MPa. In turn, the samples prepared using the self-etching adhesive system of the VII gener-ation G Bond (GC) turned out to be the least resistant to fracture of the four adhesive systems considered, they could withstand only a force of 265.20±3.76 N and a volt-age of 21.10±0.30 MPa. Conclusion. Тhe most resistant to mechanical stress were the samples, in the preparation of which an adhesive system of the IV generation OptiBond FL (Kerr) was used. The least fracture-resistant of the four adhesive systems considered were the samples prepared using the self-etching adhesive system of the VII genera-tion G Bond (GC)

Assessment of bond performance of the current self-etch adhesive systems to dentin after aging

Assessment of bond performance of the current self-etch adhesive systems to dentin after aging

Impact of radiotherapy and shielding on the efficacy of the self-etch adhesive technique.

Context:The exposure to gamma radiation affects the enamel and dentin in teeth restored with composite restoration, but a little has been done to protect from the detrimental effect.Aims:The aim of this in vitro study was to evaluate the effect of gamma radiation, with or without shielding (0.5 mm thickness of lead), in Class V cavities prepared on teeth exposed before and after restoration using the self-etch adhesive technique.Methods:A total of 75 intact teeth were selected. The samples were divided into five groups: Group I (15 teeth) not exposed to gamma radiation. Group II and III exposed to gamma radiation as per the standardized radiation protocol (2 Gy/day for 5 days/week = 10 Gy/week for 6 weeks = 60 Gy). Group III shielded, using a “0.5 mm thickness of lead” molded into a “C” shaped tube. Standardized Class V cavities were prepared on the buccal surface of all teeth and were restored by composite. Groups IV (not shielded) and V (shielded) were then exposed to standardized radiation protocol. All the samples were evaluated for the assessment of microleakage under stereomicroscope.Statistical Analysis Used:Statistics were tabulated using the Kruskal–Wallis ANOVA test.Results:Samples showed a significant difference in dye penetration scores.Conclusions:The samples restored before being exposed to gamma radiations performed better. Shielding with 0.5 mm of lead has shown increased efficacy of self-etch adhesive system irrespective of the stage of exposure.

Effect of saliva contamination on the bond strength of single-step and three-step adhesive systems.

The aim of this study was to evaluate the effect of saliva contamination on bond strength to dentin with an etch-and-rinse and a self-etch adhesive system. For each of these adhesive systems, the dentin surface of 24 human molars were allocated to one of four groups representing different saliva contamination scenarios. Saliva was applied at different stages in the bonding process, and was investigated to be remedied by water rinsing and/or air drying. Uncontaminated tooth surfaces were used as controls. Bonding procedures were performed according to the manufacturer's instructions, and a polymer-based composite was placed. The bond strength was measured by a micro-tensile test. Except for the etch-and-rinse approach having contamination with saliva after etching, followed by air drying, all salivary contamination regimens resulted in a substantial number of specimens not surviving the test, and the bond strength value of these was therefore set to 0MPa for the purposes of the statistical analysis. Water rinsing after etching and salivary contamination did significantly reduce the bond strength. Contamination after priming showed the lowest bond strength. For the self-etch approach, saliva contamination before the adhesive procedure, followed by air drying, significantly reduced the bond strength, while contamination followed by water rinsing or air drying did not statistically significantly reduce the strength.

Evaluation of Microleakage in Resin Composites Bonded to an Er:YAG Laser and Bur-Prepared Root and Coronal Dentin Using Different Bonding Agents.

Introduction: This study was conducted to assess the microleakage in Er:YAG laser-ablated and bur-prepared root and coronal dentin cavities using self-etch and total-etch adhesive systems. Methods: Sixty extracted caries-free human third molars were sectioned for dentin exposure. Then, two standard class V cavities were prepared in the root and coronal dentin of each tooth and allocated to one of the following conditioning groups randomly (n=12/Group): G1: Diamond bur for cavity preparation and single bond (BESB) etch-and-rinse adhesive for bonding, G2: Er:YAG laser (160 mJ, 20 Hz, 29.88 J/cm2) and SB (LESB), G3: Er:YAG laser and SB without acid etching (LSB), G4: Diamond bur and Clearfil SE Bond (BCSE) self-etch system, and G5: Er:YAG laser and Clearfil SE Bond (LCSE). The cavities were filled with Z100 composite resin. Dye penetration was assessed after thermocycling. Data analysis was done by Kruskal-Wallis and Mann-Whitney U tests. Statistical significance was set at P<0.05. Results: The results showed there were no statistically significant differences in microleakage between the two preparation methods (bur and laser) or the bonding agents applied (P>0.05). Regardless of the cavity preparation method, dye penetration was significantly higher in coronal dentin than in root dentin (P<0.05). Conclusion: The Er:YAG laser had the same efficacy as the conventional method for cavity preparation, and microleakage did not depend on the bonding agent. Microleakage was significantly higher in coronal restorations than in root restorations.

Short-term effect of adhesive system on clinical performance of bulk fill composite

Aim: Although bulk fill composites have been widely used as restorative material, there is no consensus regarding the best clinical protocol in terms of composite technique and adhesive system. Therefore, this clinical trial evaluated the clinical performance of bulk fill composites for class I restorations under different protocols. Methods: A randomized clinical trial including 155 class I restorations was conducted using different adhesive systems: conventional technique (phosphoric acid + conventional three-step adhesive system) (Group 1, 2 and 3); or self-etching adhesive system (Groups 4, 5 and 6). Control groups 1 and 4 were restored with conventional composite; groups 2 and 5 with low viscosity bulk fill and conventional composite as occlusal coverage; groups 3 and 6 with high viscosity bulk fill. The FDI criteria was used for clinical evaluation at baseline and after 6 months. Results: All groups showed good clinical performance. At baseline, the adhesive system did not affect postoperative hypersensitivity. After 6 months, group 5 showed a significant reduction in color and translucency; group 6 a reduction in terms of anatomical form and for postoperative sensitivity and an improvement in patient satisfaction (p&lt;0.05). Considering the same restorative technique, the use of the self-etching adhesive system showed a significant decrease in color and translucency (p&lt;0.05). Conclusion: All groups showed favorable clinical performance, and promising results were found for the conventional adhesive system and high viscosity bulk fill protocol.

Effect of Saliva Contamination on Shear Bond Strength of Self-etch Adhesive System to Dentin: An In Vitro Study.

Aim and objectiveThis study aimed to evaluate the outcome of saliva contamination on shear bond strength (SBS) of a self-etch adhesive system to dentin.Materials and methodsA total of 60 premolars were selected. Occlusal surfaces of the teeth were severed off. Three groups of 20 teeth in each were formed after the samples were randomly divided. Group I: Not subjected to any contamination (control group). Group II: Contamination with saliva occurred before coating the teeth with a self-etch adhesive system. Group III: Contamination with saliva occurred after coating the teeth with a self-etch adhesive system. After the contamination, the composite was placed with the help of a Teflon tube. Under the universal testing machine, the SBS of these samples was then tested.ResultsThe data obtained after testing were analyzed using SPSS software. Statistical difference was seen between all the three groups. Group II projected the least SBS.ConclusionContamination with saliva has a deleterious effect on the SBS. Contamination that occurs before the application of adhesive systems has shown considerably reduced SBS.Clinical significanceThis study successfully established that saliva contamination acts as a major factor in reducing the SBS of the bonding agent. Hence, in clinical situations, it is necessary to ensure sufficient steps are taken to eliminate or reduce the chances of contamination with saliva to aid in the success of the restoration.How to cite this articleChaudhari RR, Srivastava HR, Raisingani D, et al. Effect of Saliva Contamination on Shear Bond Strength of Self-etch Adhesive System to Dentin: An In Vitro Study. Int J Clin Pediatr Dent 2021;14(4):443–446.

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.

Comparison of successful outcome of pit and fissure sealants bonded with etch-and-rinse adhesive and self-etch adhesive system.

Dental caries is one of the most common diseases around the world. The newly erupted permanent posterior teeth are at great risk due to the complex occlusal morphology of pits and fissures, infraocclusion and incomplete maturation of enamel. Pit and fissure sealants are the treatment of choice in such conditions. To compare the successful outcome of pit and fissure sealants bonded with etch-and-rinse adhesive system and self-etch adhesive systems in newly erupted permanent first molars. This randomized clinical trial was conducted at the Fatimah Jinnah Dental Hospital from June 2017 to May 2019. Children aged between 6 to 9 years who fulfilled the inclusion criteria were recruited for this study after parents' consent. Patients were randomly divided into two groups by the lottery method. Thirty patients with 60 first molar teeth in Group A were treated with etch-and-rinse adhesive system, while the other thirty patients with 60 first molar teeth in Group B were treated with self-etch adhesive system. After adhesive placement, all children received the same fissure sealants in newly erupted maxillary and mandibular permanent first molar. Each group was clinically evaluated at 6 and 12 months follow-up visit. Modified United States Public Health Service (USPHS) criteria were used for direct clinical evaluation of successful outcomes such as sealant retention and marginal discoloration. Successful outcome was statistically significant in Group B compared to Group A (60% vs. 30% p= 0.020) at 12months follow-up. Stratification analysis was performed with respect to age in which a successful outcome was not significant (p= 0.43) between groups for 6 to 7 years of age, while it was significant (p= 0.012) between groups in 8 to 9 years of age children. Self-etch adhesive system is better than etch-and-rinse adhesive system in terms of long-term sealant retention. In addition, the bonding procedure is simple with relatively short clinical application time therefore it would offer great benefit to clinicians in treating pediatric patients.

Does Addition of 10-MDP Monomer in Self-etch Adhesive Systems Improve the Clinical Performance of Noncarious Cervical Lesion Restorations? A Systematic Review and Meta-analysis.

Functional acidic monomers are able to chemically interact with hydroxyapatite, and this bond appears to be very stable. Therefore, this aspect of the 10-MDP molecule made it attractive and added to self-etch adhesives. The objective of this Systematic Review (SR) and Meta-analysis (MA) was to determine whether systems with the 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) functional monomer in their formula showed better clinical performance in restorations placed in noncarious cervical lesions (NCCL) when compared to systems without it. The PROSPERO registration number of the MA is CRD42016050538. An e-search was conducted through MEDLINE via PubMed, Cochrane Library, Scopus, Web of Science, OpenGrey, Clinical Trials, Current Controlled Trials, and EU Clinical Trials Register, and a search through the references of included studies was also performed. Randomized Controlled Clinical Trials, in which the effectiveness of self-etch adhesive systems, with or without the 10-MDP functional monomer for NCCL, was discussed, were included. Risk of bias was performed according to the Cochrane Collaboration tool, and the certainty of evidence was evaluated through GRADE. The data were grouped, heterogeneity (I2) was tested, and after duplicate removal, 4208 manuscripts were retrieved. From these, 11 studies were included in the qualitative analysis (risk of bias), with nine classified as low risk and two unclear. GRADE analysis detected moderate-to-high certainty of evidence, so the quantitative synthesis [Meta-analysis (MA)] was performed including the 11 studies. There were no statistical differences in the clinical performance of restorations conducted using "with or without 10-MDP" adhesive types, for all evaluated criteria (p=0.05), with heterogeneity ranging from 0% to 53%. Thus, the presence of 10-MDP functional monomer did not influence the clinical performance of restorations placed in NCCL.

Bonding performance of self-etch adhesives to enamel bleached with different peroxide concentrations.

The aim of this study was to evaluate the micro-shear bond strength (µSBS) of one and two steps self-etch adhesive systems after enamel bleaching with photo-activated bleaching systems of different hydrogen peroxide (HP) concentration. Occlusal enamel of forty intact human molars were flattened and assigned into four groups. GI Unbleached, GII, GIII, and GIV were bleached with Pyrenees (3.5% HP), GC TiON (20% HP), and Hi-Lite (35% HP) respectively. Enamel treatment with one and two steps self-etch adhesives (Clearfil S3 Bond- S3, and Clearfil SE Bond-SE) then micro-tubes were fixed on enamel and filled with AP-X composite (n=5). Bond was tested with the universal testing machine. Data were analyzed using two-way ANOVA and Tukey's tests at 5 % level of significance. The µSBS was significantly different between adhesives (F=154.46; p<0.05) and bleaching systems (F=77.33; p<0.05) with significant interaction. Specimens bonded with S3 shows a significantly lower μSBS than those bonded with SE (p<0.05) in all groups. For both adhesives the bleached groups demonstrate lower µSBS than unbleached except specimens bleached with Pyrenees and bonded with SE (p>0.05). A significant difference was observed between groups of the bleaching systems (p<0.05). Different peroxide concentrations photo-activated bleaching systems adversely affect μSBS of one and two steps self-etch adhesives. Low concentration system (Pyrenees) does not influence the bond strength of two steps adhesive.

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.

Invitro Effect of Bulkfill and Incremental Application Techniques with Different Composite Filling Materials on Marginal Microleakage

Abstract &#x0D; Objective: To assess the in vitro effect of bulkfill and incremental application techniques on the microleakage of class II dental cavities filled with three different bulkfill composite materials at occlusal and cervical margins.&#x0D; Methods: Standardized class II cavities were prepared on 120 human premolar teeth extracted for orthodontic treatment, which were randomly divided into two main groups of 60 teeth, corresponding to the two application techniques. Each group wasthen sub-dividedrandomly into three sub-groups based on the type of bulkfill restorative materials as follows: Tetric®N-Ceram BulkFill, Filtek™BulkFill flowable restorative material and X-trafil®BulkFill. All cavities were prepared and etched, and the corresponding self-etch bond adhesive systems were applied. A stereomicroscope was used to assess microleakage after thermocycling and immersion of the specimens in 0.1% methylene blue for 24 hours. Mann-Whitney U test was then used to analyze data.&#x0D; Results: No statistically significant difference was found in the marginal microleakage between the incremental and bulkfill techniques using the three types of composite materials at both occlusal and cervical margins. The X-trafil®BulkFill showed the lowest score of microleakage with both application techniques compared to other bulkfill composite materials.&#x0D; Conclusion: Both incremental and bulkfill application techniques using Tetric®N-Ceram BulkFill, Filtek™BulkFill flowable restorative material and X-trafil®BulkFill composite materials have a comparable effect on the marginal microleakage at occlusal and cervical margins of human teeth extracted from dental clinics in Sana’a city. Further studies are recommended to assess the clinical success of bulkfill composite materials using SEM or confocal microscope.&#x0D;

Invitro Effect of Bulkfill and Incremental Application Techniques with Different Composite Filling Materials on Marginal Microleakage

Abstract &#x0D; Objective: To assess the in vitro effect of bulkfill and incremental application techniques on the microleakage of class II dental cavities filled with three different bulkfill composite materials at occlusal and cervical margins.&#x0D; Methods: Standardized class II cavities were prepared on 120 human premolar teeth extracted for orthodontic treatment, which were randomly divided into two main groups of 60 teeth, corresponding to the two application techniques. Each group wasthen sub-dividedrandomly into three sub-groups based on the type of bulkfill restorative materials as follows: Tetric®N-Ceram BulkFill, Filtek™BulkFill flowable restorative material and X-trafil®BulkFill. All cavities were prepared and etched, and the corresponding self-etch bond adhesive systems were applied. A stereomicroscope was used to assess microleakage after thermocycling and immersion of the specimens in 0.1% methylene blue for 24 hours. Mann-Whitney U test was then used to analyze data.&#x0D; Results: No statistically significant difference was found in the marginal microleakage between the incremental and bulkfill techniques using the three types of composite materials at both occlusal and cervical margins. The X-trafil®BulkFill showed the lowest score of microleakage with both application techniques compared to other bulkfill composite materials.&#x0D; Conclusion: Both incremental and bulkfill application techniques using Tetric®N-Ceram BulkFill, Filtek™BulkFill flowable restorative material and X-trafil®BulkFill composite materials have a comparable effect on the marginal microleakage at occlusal and cervical margins of human teeth extracted from dental clinics in Sana’a city. Further studies are recommended to assess the clinical success of bulkfill composite materials using SEM or confocal microscope.&#x0D;

Fluoride-Releasing Self-Etch Adhesives Create Thick ABRZ at the Interface.

A fluoride-releasing adhesive system is expected to promote mineralization of demineralized dentin/enamel around a composite restoration, thereby contributing to the longevity of the restoration. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) observations revealed the formation of an “acid–base resistant zone” (ABRZ) beneath the hybrid layer when dentin was treated with a self-etch adhesive system. A thicker ABRZ was formed from the upper slope to the end of the outer lesion, indicating greater resistance against an acid-base challenge, when a fluoride-releasing self-etch adhesive system was used. The slope formation of a fluoride-releasing adhesive is believed to be due to fluoride-release from the adhesive. Quantitative assessment of the acid resistance was performed at the interface using the region of interest (ROI) mode of a digital image analysis software package. The area of the ABRZ is influenced by the concentration of fluoride release from the adhesive resin. The threshold of fluoride concentration in the adhesive may exist to influence the morphology of the ABRZ. X-ray absorption fine structure (XAFS) analysis of the dentin treated with different concentrations of NaF-mouth rinses suggested that different fluoride concentrations result in the formation of different chemical compounds, such as fluorapatite and CaF2-like structures, on the dentin surface. This may explain the differences in μTBS values and morphological appearance of the ABRZ. NaF is effective in enhancing the enamel/dentin bond durability and also helps create a high quality of ARBZ to improve the clinical success of restorations.

Influence of two carbodiimides on the bond strength of universal adhesives to dentin.

The pretreatment of dentin with cross-linking agents during bonding procedures has been proposed to improve the mechanical properties of the collagen in the hybrid layer and reduce the biodegradation of the adhesive interface. The aim of this study was to evaluate the influence of pretreatment with two carbodiimides on the dentin bond strength of universal adhesives, after thermocycling. Three universal adhesives in the self-etching mode were used (Single Bond Universal-SBU, Clearfil Universal-CLU and Ambar Universal-ABU). A self-etching adhesive system (Clearfil SE Bond-CSB) was used as control. Two carbodiimides, 1-ethyl-3-(3'-dimethylaminopropyl)-carbodiimide (EDC) and N,N'-dicyclohexylcarbodiimide (DCC), were applied for 1min. The excess solution was removed with absorbent paper and the universal adhesives were applied. The specimens were stored for 24h in distilled water at 37°C or 10,000 thermal cycles (5-55°C, 30s) and then were prepared for microtensile bond strength test (n = 4 teeth, average of 21 sticks per group). Data were analyzed using three-way ANOVA and Tukey's (α = 5%). After 24h, SBU and CSB had statistically similar bond strength values for the control groups (22.07 ± 9.03 and 19.82 ± 7.28MPa), with EDC (30.21 ± 11.30 and 19.67 ± 5.36MPa) and DCC (30.12 ± 13.43 and 19.82 ± 7.28MPa) pretreatments (p > 0.05). The use of EDC (32.57 ± 9.60MPa) and DCC (24.71 ± 9.87MPa) showed statistically higher bond strength for CLU than for the control group (14.62 ± 6.16MPa; p < 0.05). After thermocycling, the SBU, CLU, and CSB groups showed statistically similar bond strengths with the use of EDC (27.08 ± 8.44; 18.74 ± 5.41; and 24.55 ± 10.43MPa) and without the use of cross linkers (20.06 ± 7.99; 22.55 ± 9.04; and 26.54 ± 10.13MPa; p > 0.05). Groups tested after 24h in distilled water presented higher bond strength than those submitted to thermocycling. It can be concluded that the use of cross linkers influenced the immediate bond strength of the universal adhesives, and this was dependent on the combination of the adhesive system and type of carbodiimide. The use of EDC increased the immediate bond strength of CLU. DCC increased the bond strength of ABU at 24h, but the values were lower than those of the control group after aging for three out of the four adhesives.

Comparative assessment of long-term bond strength between fiber post and root dentin with and without 6.5% cocoa seed extract pretreatment – An in vitro study

Background: Cocoa seed extract (CSE) is a natural cross-linker or biomodifier, which contains proanthocyanidin that increases the immediate resin-dentin bond strength as well as reduces the dentinal matrix degradation. There are very few studies which shows the long-term effects of the cross-linking agents on radicular dentin. Aim: The aim of this study was to assess and compare the effect of 6.5% cocoa seed extract (CSE) on long-term push out bond strength between fiber post and root dentin cemented by using two different adhesive systems – total etch adhesive system and self-etch adhesive system. Materials and Methods: Sixty extracted permanent maxillary central incisors were decoronated to standardize the root length. Root canal preparation followed by postspace preparation was done. Specimens were then randomly divided into four groups according to the adhesive technique and CSE pretreatment – Group 1: Total-etch adhesive + without 6.5% CSE treatment, Group 2: Total-etch adhesive + with 6.5% CSE treatment for 10 min, Group 3: Self-etch adhesive + without 6.5% CSE treatment, and Group 4: Self-etch adhesive + with 6.5% CSE treatment for 10 min. Fiber posts were cemented with resin cement, and then, specimens were stored in an incubator for 180 days. Specimens were then tested for pushout bond strength using the universal testing machine. Statistical analysis was performed using the one-way ANOVA followed by Tukey's post hoc analysis. Results: CSE-treated groups showed higher bond strength than nontreated group. Group 2 showed significantly higher bond strength among all groups. Conclusion: The pretreatment with Proanthocyanidines containing CSE can be a natural alternative to improve the long-term resin–dentin bond strength.

РЕСТАВРАЦИЯ ЗУБОВ НА ОСНОВЕ КОНЦЕПЦИИ «ПРЕДВАРИТЕЛЬНОГО ПОЛИРОВАНИЯ ДЕНТИННОГО СЛОЯ КОМПОЗИТА»

After studying various methods of restoring teeth in the oral cavity, we came to the conclusion that no one technique is perfect. This article describes clinical cases, as well as laboratory studies that allow us to judge the effectiveness of dental restoration based on the concept of "pre-polishing of the dentin layer of the composite". The quality of the surface characteristics of the restorations of the anterior group of teeth made of pre-polymerization composite materials was analyzed. The aesthetic restoration of teeth was performed using the classical method of layer-by-layer application and photopolymerization of the composite, as well as the proposed method based on the concept of pre-polishing of the dentin layer of the composite material. After adequate anesthesia and odontopreparation, a portion of the composite material that recreates the dentine layer is introduced into a pre-prepared and isolated from the oral fluid cavity, adapted to the hard tissues of the tooth, and then photopolymerized with a dental lamp. Next, the created layer is polished to a mirror shine and re-adhesive treatment with a self-etching adhesive system, photopolymerization. The next transparent layer of the composite material, imitating enamel, is applied to the "petal" of the polished dentine (inner) layer of the material to the enamel-dentine border with the obligatory imitation of mamelon and the surface structure of the restored tooth and its cutting edge is formed in a generally accepted way. After the final photopolymerization, the final grinding and polishing is carried out. The proposed method of aesthetic restoration of teeth, based on the concept of pre-polishing the dentine layer of the composite material, allows you to achieve a higher quality of restoration, and guarantees long-term preservation of color, gloss and edge fit of the restoration of the frontal group of teeth.

Evaluation of Inhibitory Effect of Self-Etch Adhesives Incorporated with Proanthocyanidin on Cysteine Cathepsins Present in Dentin Hybrid Layer Using Gelatin Zymography: An In vitro Study.

Aim:The aim of the study is to evaluate the inhibitory effect of single-bottle and two-bottle self-etch adhesive system after surface pretreatment with 6.5% proanthocyanidin (PA) on cysteine cathepsins (CCs) present in dentin hybrid layer using gelatin zymography.Materials and Methods:Thirty-five samples of dentin measuring 3 mm × 3 mm were obtained from 35 caries-free human third molars which were divided into seven groups. The bonded specimens were cut vertically into 1 mm thick adhesive/dentin interfaces with microtome and were pulverized into powder and subjected to zymography analysis for enzymatic activity.Results:Group VI and VII which were positive control groups had shown thicker clear bands of 50 kDa. Group IV and V which had the administration of chlorhexidine showed thicker clear bands of 50 kDa which indicated slight activity of CCs. Group II in which PA used along with single-bottle system also showed thicker clear band of 59 kDa. CCs could be active due to strong acidic nature of monomer in this group. Group III in which PA used along with two bottle system had no band formation where there is crosslinking of catalytic and allosteric domains of enzymes by PA.Conclusion:Under the limitations of this study, PA proved as a non-specific natural inhibitor of CCs. Two-bottle system showed inhibition of CCs and single bottle system failed to inhibit their activity. Future research have to be done on the bond strength and durability of self-etch adhesives after using PA and its effect on long term survival of the restorations.