Effect of dentin biomodification techniques on the stability of the bonded interface.

AIM: The aim of this study is to evaluate the effect of different bonding techniques ethanol wet bonding and dimethyl sulfoxide (DMSO) wet bonding and a novel collagen cross-linker Quercetin application on the durability of resin-dentin bond and observe the bonded interface under the scanning electron microscope (SEM). MATERIALS AND METHODS: For shear bond strength testing, flat coronal dentin surfaces were prepared on 110 extracted human molars. Teeth were randomly divided into five experimental groups according to different surface pretreatments techniques. Group A was control group without any surface pretreatment. In Group B, ethanol wet bonding pretreatment was done before the application of adhesive. In Group C, DMSO wet bonding was done before the application of adhesive and in Groups D and E, Quercetin along with ethanol and Quercetin along with DMSO pretreatment, respectively, were done before adhesive application. Composite restorations were placed in all the samples. Twenty samples from each group were subjected to immediate and delayed (9 months) shear bond strength evaluation. In addition, two samples per group were subjected to the scanning electron microscopic analysis for the observation of resin-dentin interface. STATISTICAL ANALYSIS: Data collected were subjected to the statistical analysis using the one-way analysis of variance and post hoc Tukey's test at a significance level of P < 0.05. RESULTS: Dentin pretreatment with all the techniques resulted in significantly higher resin-dentin bond strength after 9 months storage with DMSO group showing the highest bond strength values. CONCLUSION: It can be concluded that these biomodification techniques can improve the durability of the resin-dentin bond.

Effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin.

OBJECTIVES: This in vitro study evaluated the effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin. MATERIALS AND METHODS: Flat coronal dentin surfaces were prepared in 120 extracted human molars. Teeth were randomly divided into 5 groups (n = 24) according to 5 different surface pre-treatments: No pre-treatment (control); 1M carbodiimide (EDC); 0.1% epigallocatechin-3-gallate (EGCG); 2% minocycline (MI); 10% sodium ascorbate (SA). After surface pre-treatment, adhesive (Adper Single Bond 2 [SB], 3M ESPE) was applied. Composite was applied into transparent plastic tubes (2.5 mm in diameter), which was placed over the bonded dentin surface. From each group, 10 samples were subjected to shear bond strength (SBS) evaluation at 24 hours (immediate) and remaining 10 samples were tested after 6 months (delayed). Additionally, 4 samples per group were subjected to scanning electron microscopic analysis for observation of resin-dentin interface. The data were statistically analysed with Shaperio­Wilk W test, 2-way analysis of variance (ANOVA), and post hoc Tukey's test. RESULTS: At 24 hours, SBS of all surface pre-treatment groups were comparable with the control group, with significant differences found between EDC and SA groups only (p = 0.009). After 6 months storage, EDC, EGCG, and MI pre-treatments preserved the resin-dentin bond strength with no significant fall. CONCLUSIONS: Dentin pre-treatment with all the dentin biomodifiers except SA resulted in significant preservation of resin-dentin bond over 6 months storage period, without negatively affecting the immediate bond strength of the etch and rinse adhesive tested.

Effect of carbodiimide on the structural stability of resin/dentin interface.

Clinical longevity of composite resin restorations is a significant problem in adhesive dentistry. Most of the current simplified adhesives present good immediate bonding, but the bond strength gradually falls over a period due to biodegradation at the resin-dentin interface. Various strategies have been proposed to improve the durability of resin-dentin bond including the use of matrix metalloproteinases inhibitors and collagen cross-linkers, biomimetic remineralization, ethanol wet bonding, to improve the physical and mechanical properties of the bonding substrate, i.e., dentin. However, all are under preliminary research and without any conclusive evidence. Therefore, this paper addresses the current challenge in dental adhesion, i.e., poor durability of resin-dentin bond and introduces the concept of dentin biomodification as an alternative way for improving the long-term bonding effectiveness of current adhesives to dentin and also provides an overview of a synthetic collagen cross-linking agent carbodiimide (EDC) including its mechanism of action, literature review of studies evaluating EDC, variables associated with its use and its cytotoxicity. Search was performed across the electronic databases (PubMed, Ebsco host, and Google search engine) to identify manuscripts for inclusion, using the keywords: carbodiimide, dentin bonding, durability, resin-dentin interface, and collagen cross-linking. Thirty-five articles were finally included, and the last search was made in February 2016.

Effect of EDTA Conditioning and Carbodiimide Pretreatment on the Bonding Performance of All-in-One Self-Etch Adhesives.

Objective. This study evaluated the effect of ethylenediaminetetraacetic acid (EDTA) conditioning and carbodiimide (EDC) pretreatment on the shear bond strength of two all-in-one self-etch adhesives to dentin. Methods. Flat coronal dentin surfaces were prepared on one hundred and sixty extracted human molars. Teeth were randomly divided into eight groups according to two different self-etch adhesives used [G-Bond and OptiBond-All-In-One] and four different surface pretreatments: (a) adhesive applied following manufacturer's instructions; (b) dentin conditioning with 24% EDTA gel prior to application of adhesive; (c) EDC pretreatment followed by application of adhesive; (d) application of EDC on EDTA conditioned dentin surface followed by application of adhesive. Composite restorations were placed in all the samples. Ten samples from each group were subjected to immediate and delayed (6-month storage in artificial saliva) shear bond strength evaluation. Data collected was subjected to statistical analysis using three-way ANOVA and post hoc Tukey's test at a significance level of p < 0.05. Results and Conclusion. EDTA preconditioning as well as EDC pretreatment alone had no significant effect on the immediate and delayed bond strengths of either of the adhesives. However, EDC pretreatment on EDTA conditioned dentin surface resulted in preservation of resin-dentin bond strength of both adhesives with no significant fall over six months.

Bonding efficacy of etch-and-rinse adhesives after dentin biomodification using ethanol saturation and collagen cross-linker pretreatment.

AIM: To evaluate whether the application of two simplified etch-and-rinse adhesives to biomodified dentin using ethanol-wet bonding (EWB) and collagen cross-linker (CCL) pretreatment improves their sealing ability. MATERIALS AND METHODS: In 176 extracted human molars, the pulp-chambers were deroofed, and teeth were sectioned horizontally. Samples were randomly divided into eight groups according to four bonding techniques using two simplified etch-and-rinse adhesives; Adper Single Bond 2 (ASB) and XP Bond (XPB). The bonding protocols included: (a) Water-wet bonding (WWB); (b) EWB; (c) WWB and CCL application; (d) EWB and CCL application. After composite resin restorations, dye leakage evaluation and scanning electron microscope analysis were done. Leakage scores were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests at a significance level of P < 0.05. RESULT: For both ASB and XPB adhesives, least dye leakage was observed in EWB groups (b and d) (P = 0.918 and P = 0.399 respectively) which showed no significant difference, while maximum leakage scores were seen in WWB groups (a and c). Regardless of CCL application and adhesives used, EWB technique depicted (P = 0.003 and P = 0.004) significantly greater sealing ability than WWB. CONCLUSION: Bonding of ASB and XPB using EWB significantly improved their sealing ability. Biomodification using CCL pretreatment had no significant effect on the sealing ability of adhesives bonded with either WWB or EWB.

Influence of double application technique on the bonding effectiveness of self-etch adhesive systems.

AIM: To evaluate and compare the effect of double-application of single-step self-etch adhesives using microleakage study and to analyze the dentin-adhesive interfacial micromorphology. METHODS: In total, 72 extracted human premolars were divided into three groups for different self-etch adhesives (G Bond, GC [GB], Optibond, Kerr [OB], and Xeno V Plus, Dentsply [XV]). Class V cavities were prepared. Each group was further divided into two subgroups (n = 10) according to the placement technique of the adhesive, using the single-application [subgroup (a)] or double-application method [subgroup (b)]. Resin composite (Z 250, 3M ESPE, St. Paul, MN) was used to restore the cavities and light cured for 40 s. Twenty samples from each group were subjected to microleakage study. Two samples from both the subgroups of the three adhesives were used for scanning electron microscopic examination of the resin-dentin interfacial ultrastructure. Dye leakage scores were subjected to statistical analysis using Kruskal-Wallis and Mann-Whitney U-tests at significance level of P < 0.05. RESULTS: GB depicted significantly more microleakage which was significantly greater than OB and XV. The double application led to significant decrease in microleakage of GB with no significant effect on the microleakage scores of other two all-in-one adhesives, that is OB and XV. CONCLUSION: Double application of all-in-one self-etch adhesives improves the marginal sealing ability in dentin although it appears to be product dependent.

Adhesive bonding to pulp chamber dentin after different irrigation regimens.

AIM: The aim of the present study was to determine the effect of ethylenediaminetetraacetic acid (EDTA) and NaOCl irrigation on the microleakage and interfacial morphology of adhesives bonded to pulp chamber dentin. METHODS: The pulp chamber roof of 72 extracted permanent molars was removed. Samples were equally divided into six groups. Pulp chamber dentin was bonded with either Adper Easy One (group 1), Adper Prompt L-Pop (group 2), or Adper Single Bond 2 (Group 3), after irrigation with either normal saline (groups 1a, 2a, 3a) or 17% EDTA and 5.25% NaOCl (groups 1b, 2b, 3b). Composite resin restorations were placed in the pulp chamber. Ten samples per group were subjected to microleakage test and scanning electron microscopic analysis was done in two samples from each group. Data were statistically analyzed using Mann-Whitney and Kruskal Wallis tests at a significance level of P < 0.05. RESULTS: EDTA and NaOCl irrigation of the pulp chamber significantly reduced microleakage in Adper Easy One. However, it had no significant effect on the microleakage of Adper Prompt L-Pop and Adper Single Bond 2. CONCLUSIONS: EDTA and NaOCl irrigation of the pulp chamber was not deleterious to the bonding of any of the adhesives tested. While this irrigation regimen had no significant effect on the microleakage of Adper Prompt L-Pop and Adper Single Bond 2, it significantly reduced the microleakage scores in Adper Easy One.

Photodynamic therapy: An adjunct to conventional root canal disinfection strategies.

Although chemical-based root canal disinfectants are important to reduce microbial loads and remove infected smear layer from root dentin, they have only a limited ability to eliminate biofilm bacteria, especially from root complexities. This paper explores the novel photodynamic therapy (PDT) for antimicrobial disinfection of root canals. The combination of an effective photosensitizer, the appropriate wavelength of light and ambient oxygen is the key factor in PDT. PDT uses a specific wavelength of light to activate a non-toxic dye (photosensitizer), leading to the formation of reactive oxygen species. These reactive oxygen molecules can damage bacterial proteins, membrane lipids and nucleic acids, which promote bacterial cell death. In, addition PDT may enhance cross-linking of collagen fibrils in the dentin matrix and thereby improving dentin stability. The concept of PDT is plausible and could foster new therapy concepts for endodontics. The available knowledge should enable and encourage steps forward into more clinical-oriented research and development. This article discusses PDT as related to root canal disinfection, including its components, mechanism of action, reviews the current endodontic literature and also highlights the shortcomings and advancements in PDT techniques.

In vitro bonding effectiveness of three different one-step self-etch adhesives with additional enamel etching.

AIM: To evaluate the effect of additional enamel etching on the shear bond strength of three self-etch adhesives. METHODS: Class II box type cavities were made on extracted human molars. Teeth were randomly divided into one control group of etch and rinse adhesive and three test groups of self-etch adhesives (Clearfil S3 Bond, Futurabond NR, Xeno V). The teeth in the control group (n = 10) were treated with Adper™ Single Bond 2. The three test groups were further divided into two subgroups (n = 10): (i) self-etch adhesive was applied as per the manufacturer's instructions; (ii) additional etching of enamel surfaces was done prior to the application of self-etch adhesives. All cavities were restored with Filtek Z250. After thermocycling, shear bond strength was evaluated using a Universal testing machine. Data were analyzed using anova independent sample's 't' test and Dunnett's test. The failure modes were evaluated with a stereomicroscope at a magnification of 10×. RESULTS: Additional phosphoric acid etching of the enamel surface prior to the application of the adhesive system significantly increased the shear bond strength of all the examined self-etch adhesives. CONCLUSIONS: Additional phosphoric acid etching of enamel surface significantly improved the shear bond strength.

Comparison of antimicrobial efficacy of propolis, Morinda citrifolia, Azadirachta indica (Neem) and 5% sodium hypochlorite on Candida albicans biofilm formed on tooth substrate: An in-vitro study.

INTRODUCTION: Endodontic infections are polymicrobial in nature. Candida albicans is the most common fungus isolated from failed endodontic cases. The constant increase in antibiotic resistant strains and side-effects caused by synthetic drugs has prompted researchers to look for herbal alternatives such as propolis, Morinda citrifolia and Azadirachta indica (Neem) etc., since, the gold standard for irrigation, i.e., sodium hypochlorite has many disadvantages. MATERIALS AND METHODS: Extracted human mandibular premolars were biomechanically prepared, vertically sectioned, placed in tissue culture wells exposing the root canal surface to C. albicans grown on Sabouraud Dextrose Agar to form a biofilm. At the end of 2 days, all groups were treated with test solutions and control for 10 min and evaluated for Candida growth and number of colony forming units. The readings were subjected to statistical analysis using analysis of variance and post hoc Tukey tests. RESULTS: Sodium hypochlorite and propolis groups exhibited highest antimicrobial efficacy against C. albicans with no statistically significant difference. It was followed by the A. indica (Neem) group. M. citrifolia had limited antifungal action followed by the negative control group of saline. CONCLUSION: According to the results of this study, propolis can be used as an effective antifungal agent similar to that of sodium hypochlorite, although long-term in vivo studies are warranted.

Long-term bonding effectiveness of simplified etch-and-rinse adhesives to dentin after different surface pre-treatments.

OBJECTIVE: To evaluate the effect of 2% chlorhexidine (CHX) and 30% proanthocyanidin (PA) application on the immediate and long-term bond strength of simplified etch-and-rinse adhesives to dentin. MATERIALS AND METHODS: One hundred twenty extracted human molar teeth were ground to expose the flat dentin surface. The teeth were equally divided into six groups according to the adhesives used, either Tetric N Bond or Solobond M and pretreatments given either none, CHX, or PA. Composite cylinder was bonded to each specimen using the respective adhesive technique. Half the samples from each group (n = 10) were then tested immediately. The remaining samples were tested after 6 month storage in distilled water. RESULTS: The mean bond strength of samples was not significantly different upon immediate testing being in the range of 8.4(±0.7) MPa. The bond strength fell dramatically in the control specimens after 6 month storage to around 4.7(±0.33) MPa, while the bond strength was maintained in the samples treated with both CHX and PA. CONCLUSION: Thirty percent PA was comparable to 2% CHX with respect to preservation of the resin dentin bond over 6 months.

Bilateral dens evaginatus (talon cusp) in permanent maxillary lateral incisors: a rare developmental dental anomaly with great clinical significance.

Talon cusp is an accessory cusp-like structure which projects from the cingulum area or cementoenamel junction. It is important for dentists to be aware of the potential complications that may occur with talon cusp. Early diagnosis and treatment is important, especially to prevent pulpal complications in permanent teeth which may be in developing stage in paediatric patients. The purpose of this paper is to report a case of bilateral talon cusp in permanent maxillary lateral incisors. Associated dental anomalies and clinical problems are discussed along with successful management of the case with conservative therapy.

Surgical management of iatrogenic perforation in maxillary central incisor using mineral trioxide aggregate.

Root perforations are undesired complications of endodontic treatment. The repair of root perforation can be accomplished using different materials and techniques. Mineral trioxide aggregate (MTA) is widely used to seal perforations because of its biocompatibility and sealability. This article describes a case report where an iatrogenic root perforation was repaired successfully with MTA in maxillary right central incisor of a 13-year-old boy.

Effect of proanthocyanidin treatment on the bonding effectiveness of adhesive restorations in pulp chamber.

OBJECTIVE: To analyze the effect of proanthocyanidin (PA) treatment of the pulp chamber dentin after NaOCl and EDTA irrigation on the microleakage and interfacial morphology of adhesive restorations. STUDY DESIGN: Pulp chambers of 66 extracted permanent molars were exposed. In half of the samples, pulp chamber dentin was bonded with Clearfil S3 after irrigation with normal saline (Group1a); 1% NaOCl and 17% EDTA (Group1b) or 1% NaOCl, 17% EDTA and 30% PA (Group1c) and in other half samples, pulp chamber dentin was bonded with Futurabond NR after irrigation with normal saline (Group 2a); 1% NaOCl and 17% EDTA (Group 2b) or 1% NaOCl, 17% EDTA and 30% PA (Group 2c). After adhesive procedures, Filtek Z 250 restorations were placed in the pulp chambers. Microleakage assessment was done in ten samples from each group and scanning electron microscopic examination was done in one sample from each group. Statistical analysis was done using Mann-Whitney and Kruskal Wallis tests at a significance level of P<0.05. RESULTS: Both the adhesives showed extensive microleakage. NaOCl and EDTA irrigation had no significant effect on the microleakage of both the adhesives. PA treatment of the pulp chamber dentin after NaOCl and EDTA irrigation significantly reduced microleakage in both the adhesives. CONCLUSION: It was concluded that 1 minute application of 30% proanthocyanidin solution in the pulp chamber after NaOCl and EDTA irrigation improved the subsequent bonding of self-etch adhesives to pulp chamber dentin.

Effect of different root canal irrigants on the sealing ability of two all-in-one self-etch adhesives: An in vitro study.

AIM: To evaluate the effect of different root canal irrigants on the sealing ability of two self-etch adhesives, using dye penetration method, within the pulp chamber. MATERIALS AND METHODS: 72 extracted human molars were divided into six groups, according to the irrigant and self-etch adhesives used. After de-roofing the pulp chamber with a carborundum disc, the pulp was extirpated using excavator and broaches. In 36 samples, pulp chambers were bonded with Xeno V after irrigation with either 2% CHX (Group1: Xe-CHX) ; 17% EDTA + 5.25% NaOCl (Group2: Xe- EDTA + NaOCl) or normal saline (Group3: Xe-NS) and in other half samples, pulp chambers were bonded with Adper Easy One after irrigation with either 2% CHX (Group 4: Ad-CHX); 17%EDTA + 5.25% NaOCl (Group5: Ad-EDTA+NaOCl) or normal saline (Group 6: Ad-NS). All the samples were restored with Filtek Z350. Ten teeth from each group were assessed for dye penetration. Two samples in each group were viewed under scanning electron microscope to observe resin-dentin interfacial adaptation. Data was statistically analyzed using Mann-Whitney and Kruskal Wallis tests at a significance level of P < 0.05. RESULTS: MEAN MICROLEAKAGE SCORES AND STANDARD DEVIATION OBSERVED WERE: Group 1 (Xe-CHX): 2.8 ± 0.42, Group 2 (Xe-EDTA + NaOCl): 2.3 ± 0.82, Group 3 (Xe-NS): 2.9 ± 0.31, Group 4 (Ad-CHX): 1.2 ± 0.91, Group 5 (Ad-EDTA + NaOCl): 0.8 ± 0.63, Group 6 (Ad-NS): 1.9 ± 0.99. CONCLUSIONS: Adper Easy One showed significantly less leakage than Xeno V when normal saline was used as an irrigant. EDTA treatment followed by NaOCl application significantly reduced microleakage and improved the interfacial adaptation with Adper Easy One. CHX did not significantly affect the sealing ability of both one-step self-etch adhesives tested.

Bonding efficacy of 1-step self-etch adhesives: effect of additional enamel etching and hydrophobic layer application.

PURPOSE: The purpose of this study was to analyze the effect of additional enamel etching and hydrophobic layer application on microleakage of 1-step self-etch adhesives. METHODS: Class V cavities were made on the buccal surfaces of 80 extracted human premolars. The teeth were divided into 2 test groups according to the 1-step self-etch adhesive used: Clearfil S(3) Bond and Xeno III. Each test group was subdivided into 4 groups (n=10) according to application mode of the adhesive: (1) Group 1=adhesive applied following manufacturer's directions; (2) Group 2=enamel etching prior to adhesive application; (3) Group 3=same as Group 1, plus application of an additional coat of hydrophobic resin layer; (4) Group 4=same as Group 2, plus application of an additional coat of hydrophobic resin layer. The adhesives were light cured, and the cavities were filled with resin composite. Specimens were thermocycled and analyzed for leakage using Kruskal-Wallis and Mann-Whitney U test at a significance level of P=.05. RESULTS: Enamel etching significantly reduced leakage in both the adhesives. Hydrophobic resin layer application significantly reduced leakage in Xeno III. CONCLUSIONS: An additional acid etching step and hydrophobic resin layer application can improve the bonding of 1-step self-etched adhesives to enamel and dentin, respectively.

Resin-tooth interfacial morphology and sealing ability of one-step self-etch adhesives: microleakage and SEM study.

OBJECTIVES: To compare microleakage of three self-etch adhesives and to analyze enamel surface morphology and interfacial morphology of resin-enamel and resin-dentin interface under scanning electron microscope (SEM). EXPERIMENTAL DESIGN: Study was conducted in 65 extracted human premolars. Class V cavities were prepared in 45 teeth and assigned to three groups (n = 15) according to three self-etch adhesives (OptiBond All-in-One, iBond, and Adper Prompt L-Pop). After restoration, 10 samples from each group were used to assess microleakage at enamel and dentin margin. Five samples from each group were used for analysis of interfacial morphology at resin-enamel and resin-dentin interface under SEM. Remaining 20 teeth were used to prepare flat enamel buccal surfaces to analyze the difference in surface morphology after treatment with three adhesives (n = 5 each) and 36% phosphoric acid treatment (n = 5). PRINCIPAL OBSERVATIONS: At enamel margin, Prompt L-Pop depicted least leakage of all the three adhesives and also showed best interfacial adaptation under SEM. At dentin margin, OptiBond All-in-One showed significant less leakage than iBond and Prompt L-Pop. On flat enamel surface, phosphoric acid produced the most retentive etching pattern when compared with the three adhesives. CONCLUSION: Prompt L-Pop showed the best bonding effectiveness in enamel, whereas OptiBond All-in-One performed significantly better in dentin.

In vitro bonding effectiveness of self-etch adhesives with different application techniques: A microleakage and scanning electron microscopic study.

AIM: To evaluate and compare the microleakage of self-etch adhesives placed under different clinical techniques and to analyze the resin-dentin interfacial ultrastructure under scanning electron microscope (SEM). MATERIALS AND METHODS: 100 extracted human premolars were divided into two groups for different adhesives (Clearfil S(3) and Xeno III). Class V cavities were prepared. Each group was further divided into four subgroups (n = 10) according to the placement technique of the adhesive, i.e. according to manufacturer's directions (Group 1), with phosphoric acid etching of enamel margins (Group 2), with hydrophobic resin coat application (Group 3), with techniques of both groups 2 and 3 (Group 4). The cavities were restored with composite. Ten samples from each group were subjected to microleakage study. Five samples each of both the adhesives from groups 1 and 3 were used for SEM examination of the micromorphology of the resin-dentin interface. RESULTS: At enamel margins for both the adhesives tested, groups 2 and 4 showed significantly lesser leakage than groups 1 and 3. At dentin margins, groups 3 and 4 depicted significantly reduced leakage than groups 1 and 2 for Xeno III. SEM observation of the resin-dentin interfaces revealed generalized gap and poor resin tag formation in both the adhesives. Xeno III showed better interfacial adaptation when additional hydrophobic resin coat was applied. CONCLUSIONS: In enamel, prior phosphoric acid etching reduces microleakage of self-etch adhesives, while in dentin, hydrophobic resin coating over one-step self-etch adhesives decreases the microleakage.

Management of Delayed Eruption of Permanent Maxillary Incisor associated with the Presence of Supernumerary Teeth: A Case Report.

A supernumerary tooth is one that is additional to the normal series and can be found in almost any region of the dental arch. Clinically, supernumerary teeth are able to cause different local disorders. It is important for the dentist to be aware of the clinical complications of supernumerary teeth, the most common being the delayed eruption of permanent teeth. Early diagnosis and management of supernumerary teeth is important to prevent the need for more complex surgical and orthodontic treatment. This case report highlights the problem of delayed eruption of permanent maxillary left central incisor in a 9-year-old boy due to two supernumerary teeth, one tuberculate type and other impacted inverted mesiodens.