Application Of Adhesive System Research Articles

Flowable bulk-fill versus layering restorative material on Class II restorations: A randomized clinical trial

ObjectiveThis study evaluated the clinical performance of Class II restorations made with flowable bulk-fill base versus conventional layering ORMOCER-based restorative material in a split-mouth randomized clinical trial. MethodsThirty patients received two class II restorations (n = 60) performed with different strategies. All preparations received the application of the universal self-etching adhesive system according to the manufacturer's recommendation, followed by the placement of a sectional matrix, wooden wedge, and separation ring. The first restoration was performed using 4 mm of flowable bulk-fill material covered by 2 mm of conventional viscosity restorative material (Bulk-fill technique). The second restoration was performed only with the conventional viscosity material, with a maximum of 2 mm thick increments, up to fill the cavity (Layering technique). After occlusal adjustment, the same polishing system was used for all restorations. Evaluations using the FDI criteria were conducted after 7 days, 12, and 24 months. Data were analyzed with the Fisher's Exact test (α=0.05). ResultsFrom 30 participants, 24 attended the 24-month recall, and 48 restorations were evaluated. All restorations received acceptable overall scores for esthetic and biological properties after this period, while only 6.66 % of the restorations exhibited unacceptable overall scores for the functional properties in both groups. No significant differences between the tested restorative materials and techniques were found for each FDI criterion assessed. The success rate after 2 years was 93.33 % for both groups. ConclusionBoth restorative materials exhibited good clinical performance for the parameters analyzed with no differences between them after 24-month follow-up. Clinical relevanceFlowable bulk-fill ORMOCER-based material is a suitable alternative for direct Class II restorations, providing good clinical outcomes and simplifying the restorative procedure. Clinical trial registration numberRBR-6mvp9w

A new method of adhesive system application improves the bond strength between fiber post and root dentin.

This study evaluated a new method of adhesive system application on the bond strength between fiber post and root dentin using two adhesive systems. The canals of sixty bovine incisors were prepared and obturated. The roots were divided into six groups (n=10) according to the adhesive system (Clearfil SE - CSE and Single Bond Universal - SBU) and the application strategy (microbrush - MB; rotary brush - RB; and ultrasonic tip - US). The glass fiber posts were cemented with resin cement (RelyX ARC). The roots were sectioned perpendicularly to their long axis, and three slices per root were obtained. Previously to the push-out test, confocal laser scanning microscopy (CLSM) was performed to illustrate the interfacial adaptation of the cement to the root canal walls. Failure patterns were analyzed with 40x magnification. Shapiro-Wilk indicated a normal distribution of the data. The bond strength values were compared using one-way ANOVA and Tukey's tests. Student's T test analyzed the differences between the adhesive systems within each third and protocol. A significance level of 5% was used. CSE with RB showed higher mean bond strength values compared to MB (conventional technique) (P < 0.05). US application resulted in intermediate bond strength values for CSE (P > 0.05). The application of SBU using RB generated higher mean bond strength values compared to MB and US (P < 0.05). Adhesive failures were predominant (65.5%). CSE and SBU application with the new rotary brush improved the bond strength of fiber posts to root dentin compared to the conventional strategy.

Analysis of intrapulpary temperature variation during the operative and restorative phase in human molars

The aim of this study was to analyze the intrapulpal temperature variation during the operative and restorative phase in human molars. This study was approved by the Research Ethics Committee, registration CAAE 43677521.6.0000.5237 and 24 samples were made from human molars divided into 2 groups, group 1 (n = 12) restored with Bulk Fill composite resin in a single increment and group 2 (n = 12) restored with conventional composite resin in two increments. The temperature was monitored and recorded with a Lutron Tm-902C digital thermostat device during preparation, adhesive system application and restoration. The mean temperature variation in ºC for cavity preparation was -2.07 ± 0.89, application of the adhesive system was 1.12 ± 0.65, restoration with Bulk Fill resin was 2.73 ± 0.72 and restoration with conventional resin was 1.94 ± 0.35. Thus, in the operative phase there was a decrease in temperature in both groups and in the restorative phase the Bulk Fill resin presented a higher temperature compared to conventional resin.

Micromorphology and analysis of dentin surfaces after preparation with Er:YAG laser and application of self-etch adhesive system with 10-MDP. A confocal laser scanning microscope study.

The purpose of this study was to analyze and compare the micromorphology of the hybrid layer and the dentinal surface when the dentin was prepared with an Er:YAG laser or burs, and to find if there was any difference if the time of application of the self-etching primer on the dentin prepared with an Er:YAG laser was doubled.

Morphological Interface Between Restorative and Pulp-Capping Materials: A Systematic Review.

Bioceramic materials (BCMs) are widely used in vital pulp therapy (VPT) for their biocompatibility and bioactivity; however, their mechanical properties are equally important in the clinical outcome of the pulp-capped teeth. To carry out an analysis of the research produced on the morphology of the interface between BM and restorative materials (RM) through a systematic review. An electronic search was performed in Scopus, PubMed, and Web of Science until December 9, 2022. The keywords used in combination with truncation and Boolean operators were: (morphology OR filtration OR porosity) AND (silicate OR composite) AND (cement) AND ("pulp capping" OR "vital pulp therapy" OR "vital pulp treatment"). Of the 387 articles initially retrieved from the electronic search databases, 5 articles met the criteria for qualitative data collection. MTA and Biodentine were the most studied BCMs. All the articles used a scanning electron microscope as a method of evaluating the samples. Sample sizes and setting times of RM and BCMs differed between studies. Three out of 5 studies used similar conditions of recorded temperature and humidity of 37°C and 100%, respectively. The different biomaterials used, the application of adhesive systems, humidity and restoration time affect the bonding performance and the ultrastructural interface between BCMs and RMs. The scarcity of research on this point makes it necessary to delve into it and study new materials to obtain more scientific evidence.

Дослідження сили адгезії фотокомпозитних емалевих герметиків до поверхні зуба

The purpose of the study was to compare an adhesion strength of some modern enamel sealants to the enamel of a developing tooth which occurs without adhesive preparation of tooth surface. Materials and methods. In laboratory the shear adhesion strength to human teeth enamel without adhesive system application was compared for “Fissurit FX” (VOCO), “Clinpro™ Sealant” (3M™ ESPE™) and “Jen-Fissufil” (Jendental-Ukraine LLC). 30 samples were tested on tensometric system. Tests were performed according to requirements of ISO 4049:2019 “Dentistry – Polymer-based restorative materials” and ISO 6874:2005 “Dentistry – Polymer-based pit and fissure sealants”. Results and discussion. Performed experimental studies of sealant adhesion (without the use of adhesive systems, only with acid etching) showed that it was the largest in the domestic “Jen-Fissufil” – 9.80 ± 1.17 MPa (M=10.42 MPa, min – 7.41 MPa, max – 11.07 MPa); less in “Fissurit FX” – 9.78 ± 1.33 MPa (M=9.43 MPa, min – 8.23 MPa, max – 12.62 MPa) and “Clinpro™ Sealant” – 9.55 ± 1.88 MPa (М=8.69 MPa, min – 6.35 MPa, and max – 14.73 MPa). The performed statistical tests did not reveal any significant differences between the adhesion strength in all three subgroups. Due to the changes in the concept of dental caries development and approaches to its control that have taken place in dentistry over the past 30 years, the role of enamel sealants in achieving caries control in individual and communal prevention of dental diseases has significantly increased. The tendency to expand the indications for the use of photocomposite enamel sealants in clinical practice is also worth noting. In addition to their direct purpose, the materials can be used for “repair” and restoration of individual photocomposite fillings with minor wear and used as a lining material for the restoration of teeth with carious cavities with a high C-factor. Conclusion. In modern dentistry the use of enamel photocomposite sealants is one of the most effective and reliable methods of preventing caries of the occlusal surfaces of teeth. The study of shear adhesion to acid-etched enamel for photocomposite materials “Fissurit FX”, “Clinpro™ Sealant” and “Jen-Fissufil” did not reveal any significant differences. The technology of composite tooth enamel sealants is currently successful in clinical practice and continues to improve and develop. The development of new and quality improvement of such materials is an urgent issue for science and technology

Color Stability of Resin Cements after Water Aging.

The color stability of resin cements plays a key role in the achievement of esthetically-pleasant restorations. Resin luting materials can be mainly divided into two main classes: adhesive (relying on previous application of adhesive systems) or self-adhesive (also known as one-step cements). The different chemical compositions determine their physio-mechanical characteristics which, in turns, influence their color stability. To evaluate the color variations of different dual-cured resin cements after water aging, 80 disc-shaped specimens (15 mm in diameter and 1.2 mm thick) were obtained from the following resin cements (n = 10): (1) Maxcem Elite Universal, MCU (Kerr); (2) RelyX Universal, RXU (3M); (3) Calibra Ceram, CAL (Dentsply); (4) Multilink, MUL (Ivoclar-Vivadent); (5) Panavia V5, PAN (Kuraray); (6) Calibra Universal, CUN (Dentsply); (7) SpeedCEM Plus, SCP (Ivoclar); and (8) Panavia SA, PSA (Kuraray). After light-polymerization, the specimens were measured with a spectrophotometer and CIELab* values were recorded. The specimens were then placed in a digitally controlled thermostatic water bath at 60° for 30 days and afterwards the color measurements were repeated. Color differences were calculated for each specimen before and after water-aging procedures with ΔEab formula and the data were statistically analyzed (p < 0.05). The type of cement statistically influenced the ΔEab (p < 0.05), with MCU showing the lowest color variations (4.3 ± 0.7) whereas RXU and PSA the highest (16.9 ± 1.6 and 16.8 ± 1.2, respectively). No differences were observed between CAL, CUN and SCP (p = 0.05). Color stability is related to the chemical composition of the resinous luting materials, thus material dependent.

Effect of Different Application Modalities on the Bonding Performance of Adhesive Systems to Dentin: A Systematic Review and Meta-Analysis.

Diverse types of dental adhesives exhibit different cytotoxic outcomes on cells in vitro. Currently, no standard adhesive application technique has so far been decisive for clinicians for better durability of resin-dentin bonds of adhesive systems. The purpose of this study was to systematically review the literature to evaluate the bonding performance of adhesive systems to dentin by using different application modalities. The systematic research strategy was conducted by two reviewers among multiple databases: PubMed, Scopus, Web of Science, Embase, and Scielo. In vitro studies reporting the effects of additional steps for the application of adhesive systems on the bond strength to dentin were selected. Meta-analysis was performed using Review Manager Software version 5.3.5 using the random effects model. The methodological quality of each in vitro study was assessed according to the parameters of a previous systematic review. The electronic research through different databases generated a total of 8318 references. After the examination of titles and abstracts, a total of 106 potentially relevant studies accessed the full-text evaluation phase. After full-text examination, 78 publications were included for the qualitative analysis, and 68 studies were included in the meta-analysis. Regarding the etch-and-rinse adhesive systems, the application modalities that improved the overall bond strength were the application of a hydrophobic resin layer (p = 0.005), an extended application time (p &lt; 0.001), an application assisted by an electric current (p &lt; 0.001), a double-layer application (p = 0.05), the agitation technique (p = 0.02), and the active application of the adhesive (p &lt; 0.001). For self-etch adhesive systems, the techniques that improved the overall bond strength were the application of a hydrophobic resin layer (p &lt; 0.001), an extended application time (p = 0.001), an application assisted by an electric current (p &lt; 0.001), a double-layer application (p &lt; 0.001), the agitation technique (p = 0.01), and the active application of the adhesive (p &lt; 0.001). The in vitro evidence suggests that the application of adhesive systems using alternative techniques or additional strategies may be beneficial for improving their bond strength to dentin. The application modalities that favored the overall bond strength to dentin were an extended application time, a double-layer application, an application assisted by an electric current, the active application of the adhesive, and the application of a hydrophobic resin layer. Worth mentioning is that some techniques are intended to increase the degree of the conversion of the materials, and therefore, improvements in the biocompatibility of the materials can be expected.

Influence of adhesive application method and thermocycling on the bonding performance of different adhesive systems to dentin

Aim: To assess the effect of multiple layers application of different adhesive systems on the microshear bond strength (μSBS) of dentin with and without thermocycling. Materials and Methods: Two hundred forty sound human premolars had their enamel surfaces removed to expose even surfaces of dentin. The teeth were mounted in acrylic resin blocks and then assigned arbitrarily into four main groups (n = 60) representing the investigated adhesives (a self-etch [SE] adhesive, a total-etch [TE] adhesive, and a multimode [MM] adhesive used in TE and SE modes). Individually, the main groups were equally alienated into three subgroups (n = 20), each representing the number of the applied adhesive layers (one layer [1L], two layers [2L], and three layers [3L]). Then, each respective subgroup was divided subsequently into two equal divisions with n = 10 each according to thermocycling (with and without thermocycling). Each occlusal surface received three composite microrods. Prepared specimens were reserved in distilled water at temperature of 37°C until the μSBS test was performed after 24 h or after thermocycling for 3000 cycles at 5°C–55°C water bath. Results: A three-way analysis of variance (ANOVA) disclosed that multilayer application, adhesive type, and thermocycling showed a significant statistical impact on μSBS. The 1L, 2L, and 3L groups showed a statistically significant difference between the groups. The 3L groups showed the highest μSBS, whereas 1L groups recorded the least μSBS. Within the adhesive groups, a statistically significant difference was evident. The highest μSBS was recorded for TE, whereas SE recorded the least μSBS. Thermocycling (TC) has a statistically significant effect on μSBS and “no-thermocycling” (T0) groups recorded higher μSBS than thermocycled groups. Conclusion: Multilayer application of the tested adhesives had the potential to increase dentin μSBS.

Wet-bonding technique with ethanol may reduce protease activity in dentin-resin interface following application of universal adhesive system.

Greater degradation of the hybrid layer is expected when a universal adhesive system is used, especially in the conventional application strategy. Therefore, it would important to evaluate the effect of the ethanol (ETH) and a potential matrix protease inhibitor (caffeic acid phenethyl ester/ CAPE) to maximize the ability to achieve stable dentin bond strength. The aim of this study was to evaluated the effect of ETH on a wet-bonding technique, and dentin pretreatments with different concentrations of CAPE in ethanolic solution, followed by application of a universal adhesive system (Single Bond Universal) to inhibit proteolytic activity. Dentin blocks were allocated to eight experimental groups according to the strategy (total-etch our self-etch) and treatments: ETH, or dentin pretreatment with CAPE (at 0.5%, 2.5%; and 5.0%). Half of each block (each hemiblock) served as the control (without dentin pretreatments) for the same group. The bonding strategy was performed (adhesive system/ restoration with composite resin). Two slices were obtained from each hemiblock and evaluated using in situ zymography. The proteolytic activity was analyzed by quantifying the green photons of the images obtained under a fluorescence microscope in three dentin locations close to the dentin-resin interface: hybrid layer (HL), underlying dentin (UD) and deep dentin (DD). Wilcoxon tests (for comparison between experimental and control groups) and Friedman and Nemenyi tests (for comparisons between interface locations) showed that there was no difference between the groups with different CAPE concentrations and the respective control groups (p>0.05). ETH reduced the proteolytic activity at the HL and UD (p<0.05). The wet-bonding technique with ETH proved effective in reducing the proteolytic activity. The use of CAPE in different concentrations solubilized in ethanol did not have a favorable effect on proteolytic inhibition. Key words:Adhesives, Hybrid layer, Dentin, Metalloproteinases.

Uncut Enamel for Optimizing Bonded Composite Restoration on Multiple Diastema Closure Cases

The main advantage of using a minimal invasive strategy concept by uncut enamel technique while doing direct composite restoration is to create a color and translucency close to the natural teeth with long-term bonding durability. Objective: This case report presents an uncut enamel technique for multiple diastema closure cases using direct composite restoration. Case Reports: an 18-year-old male and a 50-year-old female patient complained of diastema in their upper front teeth and requested aesthetic correction. Digital mock-up was made prior to the uncut enamel technique for showing the expected results to the patient and as a guidance for the clinician. Uncut enamel preparation was continued by free-hand restoration technique with a two-step self-etch adhesive system and composite resin application to correct the diastema. The teeth in the first and second cases were followed up after three months and four years, respectively. Conclusion: The uncut enamel preparation, free-hand restoration technique with two-step self-etch adhesive, and digital mock-up are viable options in the multiple diastema closure to re-create natural teeth and optimize bonding durability

Biaxial flexure strength and physicochemical characterization of a CAD/CAM lithium disilicate ceramic: effect of etching time, silane, and adhesive applications.

To evaluate the effect of different acid etching time and bonding agent (silane and/or adhesive system) on biaxial flexural strength and physico-chemical properties of a lithium disilicate ceramic. One hundred twenty ceramic discs were made and divided into 8 groups (n = 15) according to factors "etching time" (20 and 120s) with hydrofluoric acid (HF) and "bonding agent" (C, no bonding agent; S, silane, A, adhesive; and SA, silane + adhesive). After surface treatment, a resin cement layer was applied to the surface and all specimens were subjected to biaxial flexural strength (BFS) test with treated surfaces loaded in tension (1mm/min). The Weibull analyses and complementary analyses were also performed. Statistical analysis was done with 2-way ANOVA and the Tukey test (α = 0.05). ANOVA revealed that the factors "etching time" (p = 0.0003) and "bonding agent" (p = 0.007) were statistically significant. In the overall analysis, the HF120S group (272.02 ± 35.30A MPa) presented significantly higher BFS than that of HF120C (218.45 ± 17.15CD MPa) and HF20S (228.40 ± 37.83BCDMPa). On the other hand, the HF20A group (208.92 ± 31.16D MPa) had significantly lower BFS than HF120S (272.02 ± 35.30A), HF120A (254.42 ± 26.87ABC) and HF120SA (259.30 ± 36.55AB) groups (Tukey). The Weibull modulus (m) of all groups was significantly different from each other (p = 0.000). Regardless of etching time, the application of silane alone is sufficient to increase the flexural strength of glass ceramic, eliminating the need for the application of adhesive systems. Moreover, if only silane or adhesive is applied, 120-s HF application should increase the flexural resistance of the lithium disilicate ceramic. Applications of adhesive systems after silanization can be suppressed from the surface treatment protocol of glass ceramics, since it does not improve their mechanical strength.

New Dual-cure Resin-based Material in Occlusal and Occluso-proximal Restorations of Primary Teeth: Results of a Randomized Clinical Trial.

BackgroundThe clinical performance of new restorative materials must be evaluated before recommending its use in primary teeth.AimThis randomized clinical trial evaluated the survival rates of restorations in single and occluso-proximal cavities of primary teeth performed with a new dual-cure resin-based material in comparison with a resin-modified glass ionomer cement after 12 months of follow-up.Materials and methodsA total of 107 restorations were placed in 27 children by one experienced pediatric dentist. Two materials were tested: Vitremer and a dual-cure resin-based material with (CentionN+Adh) and without (Cention N-Adh) adhesive system application. Two calibrated and blinded examiners evaluated the restorations at 3, 6, and 12-month. The longevity of the restorations was analyzed using Kaplan-Meier survival curves and Log-rank test (α = 5%).ResultsThe overall survival rates after 12-month were 81.9% for Vitremer, 70.4% for Cention N+Adh, and 66.7% for Cention N-Adh, which had the poorer performance (HR = 0.54; 95% CI= 0.31-0.95; p = 0.031). When considering the type of the cavities, the difference was significant only for occluso-proximal cavities when Cention N-Adh was used (HR = 0.46; CI = 0.26-0.81; p = 0.008).ConclusionAll evaluated materials are suitable for restoring occlusal cavities after selective caries removal. However, Cention N needs to be used with adhesive in occluso-proximal cavities.Clinical significanceCention-N can be used for deciduous teeth restorations, with similar longevity rates as resin modified glass ionomer cements.Trial registration number RBR-9nqszrHow to cite this articleda Cunha CM, Wambier LM, Paris Matos TD, et al. New Dual-cure Resin-based Material in Occlusal and Occluso-proximal Restorations of Primary Teeth: Results of a Randomized Clinical Trial. Int J Clin Pediatr Dent 2022;15(1):38-46.

Characterisation of the calcium silicate-based cement-composite interface and the bonding strength with total-etch or single/two-stage self-etch adhesive systems.

Due to favourable biological and physical properties, calcium silicate-based cements (CSCs) are biocompatible materials used widely for vital pulp therapies. Sealing efficacy between the adhesive system and CSC determines the clinical success of treatment. This study aimed to evaluate the shear bond strength (SBS) of CSC to composite resin with different adhesive systems and to analyse the CSC-composite interface. Mineral trioxide aggregate (MTA) (ProRoot MTA; Dentsply Tulsa Dental, Tulsa, OK), Biodentine (Septodont, Saint-Maur-des-Fossés, France) and NeoMTA Plus (Avalon Biomed Inc., Bradenton, FL) samples (n = 90) were placed in the cavities and divided into three subgroups according to the adhesive family (n = 10). SBSs were measured using a universal testing machine. The interfaces were examined using a scanning electron microscope (SEM) (×1000). NeoMTA Plus showed significantly higher SBS values than MTA and Biodentine (P < 0.0001). The application of total-etch adhesive system over Biodentine and NeoMTA Plus provided the statistically highest bond strength (P < 0.05). However, when the SBS values of MTA subgroups were compared, different adhesive families applied over MTA did not make a significant difference in SBS values (P > 0.05). Based on SEM analyses, the specimens exhibit no gaps, cracks or delamination within the adhesive layer, which indicates a good adhesion between the CSC-composite interface in all subgroups. In conclusion, the different adhesive families used over CSC did not influence interfacial gap formation.

The Bond Strength of a Universal Adhesive System with Silane to Lithium Disilicates in Comparison with an Isolated Silane Coupling Agent.

The aim of this in vitro study was to evaluate the effects of different durations of silane coupling agent application compared to a universal adhesive system regarding the shear bond strength of two ceramic materials. A total of 120 human molars were ground to the dentinal coronal third and then fixed into an acrylic resin holder. Lithium disilicate specimens were divided into two main groups according to the ceramic type: computer-aided design/computer-aided manufacturing IPS e.max CAD and heat-pressed Initial LiSi Press GC (dimensions of 4 × 3× 3 mm). Each main group was subdivided into 6 subgroups (n = 10) according to the duration of the silane and universal adhesive system application (20, 60, or 120 seconds) on the ceramic surface before cementation; then, the cementation procedures were performed. All specimens were subjected to 5000 thermal cycles at 5 and 55°C before testing. The shear bond strength was measured using a universal testing machine. ANOVA and Scheffe post hoc test multiple comparisons tests were conducted (α = 0.05). The shear bond strength increased as the duration of the silane and universal adhesive system application increased. The highest bond value for each material was found for the silane application at 120 seconds, with a significant difference between 120 and 60, and 20 seconds for both e. max CAD and Initial LiSi materials (p = 0.029 and p ˂ 0.001, respectively). No significant difference was found between 60 and 20 seconds when silane and universal adhesive system were applied for both e. max CAD and Initial LiSi materials (p = 0.169 and p = 0.120, respectively). All groups treated with the silane primer showed significantly higher values than the universal adhesive system for each application time (p ˂ 0.001). Increasing the duration of the silane coupling agent and universal adhesive system application to 120 seconds on the ceramic surface before cementation improved the shear bond strength of the ceramic-cement interface. Ceramic pretreatment with silane could be an essential step for bonding ceramic to dentin regardless of silane presence in the universal adhesive system.

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.

Effect of Dimethyl Sulfoxide wet bonding technique on the durability of resin-dentin bond of an etch-and rinse adhesive system under in-vivo simulating conditions

Purpose: This study assessed the influence of new dimethyl sulfoxide (DMSO) containing pretreatments on the aged resin-dentin micro-tensile bond strength (μTBS) of a two-step etch-and rinse adhesive system. Methods: Occlusal enamel of forty-eight sound molar teeth were ground to expose mid-coronal dentin. Prepared specimens were restored with AdperTM Single Bond2 (SB2) adhesive systems. Prior to the adhesive system application, specimens were randomly assigned into three groups according to dentin pretreatment [no treatment (control group), ethanol wet-bonding (EtOH), or 50 vol% DMSO dissolved in ethanol (DMSO/EtOH)]. Resin composite block was build-up for each specimen. Specimens were stored under simulated IPP 20 mmHg, immersed in artificial saliva at 37 oC for either 24h or 6m. Specimens were sectioned into sticks of 1mm2 for μTBS testing using a universal testing machine. Mode of failure was analyzed using a scanning electron microscope. Three extra sticks from each subgroup were prepared and assessed for the amount of silver nitrate penetration (wt%) using energy dispersive analytical x-ray (EDAX). Data were statistically analyzed by Two-way ANOVA of Variance. Results: (DMSO/EtOH) group revealed the highest statistically significant mean bond strength and the least silver nitrate penetration compared to the (control) and (EtOH) groups at 24h and 6m. Adhesive failures was most predominant for control group at 24h, with increased percentage of mixed failure for EtOH and DMSO/EtOH groups at 24h and 6m. Conclusions: DMSO/EtOH dentin pretreatment improved the immediate and delayed resin-dentin bond.

Microleakage Comparative Evaluation of RMGIC and Alkasite with and without Adhesive System in Class V Cavity: An In Vitro Study

This study aimed to compare microleakage of resin-modified glass ionomer cement (RMGIC) and alkasite with and without adhesive system in class V cavity. Thirty class V cavities were prepared on the buccal surface. All prepared samples were randomly divided into three groups. Group I was restored with RMGIC, group II was restored with Cention N after the application of adhesive system, and group III was restored with alkasite. Samples were subjected to 200 thermocycles between temperature baths at 5ºC and 55ºC. Samples were stained with 2% methylene blue. The teeth were sectioned longitudinally, and the sections were then observed under stereomicroscope at a magnification of 20×. Statistical analysis showed that there was less microleakage in Cention N using adhesive system in both occlusal margin and gingival margin. There were significant differences between RMGIC, alkasite with adhesive system, and alkasite without adhesive system in class V cavity. Least microleakage at the occlusal margin and gingival margin was seen with Cention N using adhesive system and highest microleakage at the RMGIC. Cention N using the adhesive system affects the microleakage in the class V restoration. The study theorizes that the material restorations showed less microleakage in the occlusal margin than in the gingival margin.

Assessment of permeability of eroded dentin after the use of universal, self-etch, and conventional systems.

Dentin hypersensitivity is caused by increased dentinal permeability due to total or partial exposure of dentinal tubules, which in turn can be produced by alterations of dental structures or failure of restorative procedures. The purpose of this in vitro study was to evaluate the efficacy of the application of different kinds of adhesive systems to prevent dentin permeability before and after an erosive challenge. Fifty bovine dentin discs (6x1 mm) were prepared and the specimens were divided into 5 groups (n=10): (SB2) Single Bond 2, (SBU) Universal Single Bond, (CSB) Clearfil SE Bond, (SM) Scotchbond Multipurpose and (C) Control. Hydraulic conductance of dentin was recorded after adhesive application (HC-1) and after erosive challenge (HC-2). Dentin surface images of post-treatment and post-erosive challenge were obtained by scanning electron microscopy (SEM). Data were analyzed using Kruskal Wallis, Mann-Whitney with Bonferroni correction and Wilcoxon tests (p<0.05). Reduction in dentin permeability was observed with the application of adhesive systems (p<0.05). After the erosive challenge, dentin permeability increased for SBU and CSB (p<0.05), while SB2 and SM did not differ in HC-1 or HC-2 (p>0.05). The conventional, self-etching and universal adhesive systems reduce dentinal permeability by more than 80%, and dentin demineralization may contribute to the increased permeability of universal and self-etching systems.

Physicochemical characterization, water sorption and solubility of adhesive systems incorporated with titanium tetrafluoride, and its influence on dentin permeability

Titanium tetrafluoride (TiF4) in an aqueous solution can decrease dentin permeability, but some effects of its incorporation into adhesive systems are not yet known. Therefore, the aim of this study was to characterize the physicochemical, water sorption (WS) and solubility (SL) properties of two adhesive systems (Clearfil SE Bond/C and Scotchbond Universal/S) incorporated with 0.0% (T0), 2.5% (T2) and 4.0% (T4) titanium tetrafluoride (TiF4), and determine dentin permeability (L) after application of these adhesive systems both immediately afterwards (baseline) and after 6 months of storage. The physicochemical analyses of the incorporated solutions were performed based on evaluating particle size (PS), polydispersity index (PDI) by dynamic light scattering, and zeta potential (ZP) by electrophoresis. WS and SL tests followed ISO 4049 standards, and used a 7-day water storage period. The L test was performed by analyzing human dentin discs before and after adhesive system application, and after storage. PS and PDI were higher for CT0 and ST4 (p < 0.0001; ANOVA, Tukey). ZP was lower for CT4, ST2 and ST4 (p < 0.0001; ANOVA, Tukey). A 4.0% TiF4 incorporation showed higher WS (p < 0.05; Mann Whitney, Kruskal Wallis, Dunn). Higher SL was observed for CT0 and ST4 (p < 0.05; Mann Whitney, Kruskal Wallis, Dunn). The L value at baseline was lower for ST4, but was not different from the CT4 groups after storage (p < 0.05; Mann Whitney, Kruskal Wallis, Dunn). It can be concluded that TiF4 affected the colloidal stability of Scotchbond, but did not alter the other properties. The 2.5% TiF4 did not affect the PDI, WS or L of the Clearfil, and can be considered an alternative for reducing hybrid layer degradation.