Effect of thermo-mechanical cycling and chlorhexidine on the bond strength of universal adhesive system to dentin

Effect of enzymatic chemo-mechanical agents on adhesion of composite resin to dentin of permanent teeth: an in vitro study

PURPOSE

To evaluate and compare the effect of two enzymatic chemo-mechanical caries removal agents with conventional caries removal using rotatory instruments on the adhesion of composite resin to dentin of permanent teeth.

METHODS

The sample comprised 30 permanent molars with caries lesions extending to the dentin, randomly distributed into three groups (n = 10 each): 1-Caries removal with rotary instruments (control group); 2-Caries removal with Papacárie Duo® (F&A Laboratório Farmacêutico, São Paulo, Brazil); 3-Caries removal with Brix 3000™ (Brix S.R.L., Carcarañá, Argentina). After caries removal, the specimens were rinsed and dried. Scotchbond Universal™ adhesive (3 M, Saint Paul, Minnesota, USA) was actively applied in self-etch mode and light-cured. Resin composite increments were applied using a silicone mold (3 × 3 × 2 mm) and light-cured. Shear bond strength (MPa), work-to-debonding (J/m2), and shear modulus (kPa) were evaluated. For statistical analysis, the level of significance was set at 5%.

RESULTS

The control group presented significantly higher shear bond strength values (8.50 ± 2.69 MPa) compared to the Brix 3000™ group (5.72 ± 1.55 MPa, p = 0.008). There were no significant differences between Papacárie Duo® (6.66 ± 0.86 MPa) and the other groups (p > 0.05). Regarding work-to-debonding, the Papacárie Duo® group had a significantly higher result (2944.41 ± 450.21 J/m2) than the Brix 3000™ group (1189.41 ± 504.13 J/m2, p < 0.001) and the control group (967.10 ± 270.01 J/m2, p < 0.001). Concerning shear modulus, the control group showed a significantly higher result (558.67 ± 168.96 kPa) than the Brix 3000™ group (339.79 ± 143.78 kPa, p = 0.008) and the Papacárie Duo® group (223.04 ± 127.30 kPa, p < 0.001).

CONCLUSION

While the application of Papacárie Duo® did not negatively affect composite resin adhesion to dentin of permanent teeth, the application of Brix 3000™ reduced adhesive forces, potentially limiting its clinical use. Further investigations are warranted to elucidate the effects of these materials on dentin substrate, particularly through clinical studies.

Can a Novel Device with Pure Dry Air Increase the Shear Bond Strength of Dental Composites to Dentin? An Experimental Study

Modern conservative dentistry is taking the lead in daily clinical practice and is relying on adhesion. Whether it is a simple composite, ceramic inlays, onlays, veneers or crowns, the common factor for a successful outcome is a good bonding of these elements to dental structures. Thus, the purpose of this study was to evaluate the bond strength of resin composite to dentin when using a new device, the DENTIPURE KM™ (KM, Beirut, Lebanon), which provides a pure air flow, free of any contaminants and without humidity, when compared to other dental equipment. One hundred and eighty extracted human molars were equally divided into three groups according to the device used, the DENTIPURE KM™ (KM, Beirut, Lebanon), the KAVO™ (ESTETICA E30/E70/E80 Vision, KAVO, Biberach, Germany), or the ADEC™ (A-dec Performer 200, Newberg, OR, USA). The shear bond strength (SBS) was evaluated after 24 h of storage in distilled water on a universal testing machine. Statistical analysis was set with a level of significance at p ≤ 0.05. The results revealed that significantly different bond strength was imparted by the DENTIPURE KM™ device and the ADEC™ dental unit (p = 0.042). In conclusion, while the DENTIPURE KM™ device shows promise in providing contaminant-free air during bonding, its impact on dentin bond strength compared to devices like the KAVO™ appears minimal. Further research is needed to fully assess its potential in enhancing dentinal adhesion procedures.

Influence of Diabetes Mellitus and Universal Adhesive Application Mode on the Bond Strength of Composite Resin to Dentine

Background

The aim of the current study was to evaluate the influence of diabetes mellitus and the mode of applying a universal adhesive on the shear bond strength of composite resin to dentin.

Material and Methods

Forty teeth were extracted from diabetic individuals who had been living with diabetes for a period of 5 to 15 years. These forty teeth were divided into two groups: twenty molars from patients with type 1 diabetes and twenty molars from patients with type 2 diabetes. The remaining twenty sound human molars were collected from non-diabetic patients. The collected teeth were assigned into 3 groups, and each group was further divided into 2 subgroups. Group A (n = 20): non-diabetic (ND) where sub group IA: Universal adhesive applied in the total-etch mode (n = 10) and sub group IIA: Universal adhesive applied in the self-etch mode (n = 10). Group B (n = 20): diabetic type 1 (D1) where sub group IB: Universal adhesive applied in the total-etch mode (n = 10) and sub group IIB: Universal adhesive applied in the self-etch mode (n = 10). Group C (n = 20): diabetic type 2 (D2). Where Sub group IC: Universal adhesive applied in the total-etch mode (n = 10) and sub group IIC: Universal adhesive applied in the self-etch mode (n = 10). A Teflon mold measuring 3mm in diameter was attached to the dentin surface, used to build Filtek Z550 to a height of 3mm. The specimens were fixed to the universal testing to measure shear bond strength.

Results

There was a statistically significant difference of Mean ±SD of shear bond strength among the three tested groups. In group A, the Mean ±SD were (21.710 ± 0.638), it was decreased in group B to (14.626 ± 0.726) and group C to (17.740 ± 0.668). Subgroup I had lower shear bond strength values than subgroup II in all tested groups. The difference between each subgroup in groups A, B, and C was significant.

Conclusions

1. Diabetes mellitus has an adverse effect on the shear bond strength of composite to dentine. 2. Type 1 diabetes mellitus significantly reduces the shear bond strength of composite resin to dentin. 3. Shear bond strength of the universal adhesive was higher when applied to dentin using the self-etch mode, as compared to the total etch mode, in all groups, regardless of whether the participants had diabetes or not. Key words:Diabetes Mellitus, Universal Adhesive, Application Mode, Shear bond Strength, Dentine, Composite.

The Influence of Chlorhexidine Gluconate Dentine Pre-Treatment on Adhesive Interface and Marginal Sealing

Background and Objectives: The aim of this in vitro study was to evaluate the combined effect of a 2% chlorhexidine aqueous solution and a universal adhesive system applied in self-etch and etch-and-rinse strategies on the composite resin-dentin interface. Materials and Methods: Class V cavities were prepared on the facial and lingual surfaces of forty caries-free molars extracted for orthodontic reasons. The samples were randomly divided into two groups corresponding to the used etching protocol: I-etch-and-rinse; II-self-etch. In each tooth, one cavity was assigned for the control subgroups -IA (n = 20) and IIA (n = 20)-adhesive only, and the opposite cavity was pretreated with a 2% chlorhexidine solution-Gluco CHeX Cerkamed-subgroups IB (n = 20) and IIB (n = 20). Both sets of groups were restored using a universal adhesive system (Single Bond Universal Adhesive, 3M-ESPE) and a bulk-fill composite resin (Filtek One Bulk Fill Restorative, 3M-ESPE). The roots and the pulp tissue were then removed, and a needle connected to a perfusor with 100 mL saline solution was used for pulp pressure simulation with a hydrostatic pressure of 20 cm H₂O. Cariogenic attack was simulated using a demineralizing solution for 3 days at a constant temperature of 25 °C. The teeth were then sectioned in a facial-lingual direction and the microleakages at the occlusal and cervical margins were registered and scored using an optical Carl-Zeiss AXIO Imager A1m microscope (Carl-Zeiss). The composite resin-dentin interface was analyzed using a SEM Vega Tescan LMH II. Statistical analysis was performed using the Kruskal-Wallis test with a significance level of p < 0.05. Results: Microleakage evaluation showed no significant differences among the study groups (p > 0.05). In subgroup IA, significant differences were recorded between occlusal and cervical margins (p < 0.05). Conclusions: Application of chlorhexidine on tooth substrate before using a universal bonding system in total etch or self-etch mode has no influence on the adhesive interface in the condition of cariogenic attack. The thickness of the adhesive resin layer seems to be less uniform when using chlorhexidine, but the morphological differences at the adhesive interface have no influence on the sealing capacity of the universal bonding system, regardless of the etching strategy.

Influence of chlorhexidine 2% and sodium hypochlorite 5.25% on micro-tensile bond strength of universal adhesive system (G-Premio Bond)

Aim: One of the reasons for the failure of adhesion in composite restorations and secondary caries may be the chemical irrigants used during the endodontic treatment. NaOCl is widely used for the biomechanical preparation of root canals due to its antimicrobial properties and capacity to dissolve organic material. In addition, another very effective decontamination solution is chlorhexidine 2%. There are few studies about the effect of root canal irrigation solutions on bond strength of universal adhesives therefore, in this study we have investigated the influence of CHX 2% and NaOCl 5.25% on micro-tensile bond strength of G-Premio Bond. Methods: Twenty-four human teeth were randomly allocated to the following groups: G1, immersion in saline solution 0.9% for 30 minutes (control); G2, immersion in CHX 2% for 30 minutes; G3, immersion in NaOCl 5.25% for 30 minutes. After restoration, the dentin/resin interface was tested by micro-tensile bond strength. The surfaces morphology was analyzed by Scanning Electron Microscopy. Data were analyzed by ANOVA followed by Tukey test in SPSS software Version 24. Results: There was a statistically significant difference between G3 and G1 (P < 0.05). There were no statistically significant differences among G1 and G2, G2 and G3. Conclusion: Root canal irrigation with NaOCl 5.25% significantly reduced the micro-tensile bond strength in the G-Premio Bond at self-etch mode, but the use of CHX did not make a significant difference.

Comparison of bond strength of universal adhesives using different etching modes: A systematic review and meta-analysis

This review aims to evaluate whether the etch-and-rinse or self-etch mode is the better protocol for dentin adhesion by universal adhesives. A total of 15 articles were included in the meta-analysis. Two reviewers performed a literature search up to October 2020in four databases: PubMed, Web of Science, Embase, and the Cochrane Library. Without considering the difference in aging mode, the analysis of the immediate and long-term bond strength of dentin showed that there was no statistical significance between the etch-and-rinse and self-etch mode of universal adhesive, and the long-term bond strength decreased relative to the immediate. In vitro studies suggest that prior acid etching did not improve bond performance. Whether from the perspective of long-term bonding performance or simplifying operating procedures, the self-etch mode is preferred.

Bond Strength of Universal Adhesives to Dentin: A Systematic Review and Meta-Analysis

Currently, the availability of a wide variety of universal adhesives makes it difficult for clinicians to choose the correct system for specific bonding situations to dentin substrate. This study aimed to determine whether there are any alternative techniques or additional strategies available to enhance the bond strength of universal adhesives to dentin through a systematic review and meta-analysis. Two reviewers executed a literature search up to September 2020 in four electronic databases: PubMed, ISI Web of Science, Scopus, and EMBASE. Only in vitro studies that reported the dentin bond strength of universal adhesives using additional strategies were included. An analysis was carried out using Review Manager Software version 5.3.5 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). The methodological quality of each in vitro study was assessed according to the parameters of a previous systematic. A total of 5671 potentially relevant studies were identified. After title and abstract examination, 74 studies remained in systematic review. From these, a total of 61 studies were included in the meta-analysis. The bond strength of universal adhesives to dentin was improved by the use of one of the following techniques: Previous application of matrix metalloproteinases (MMP) inhibitors (p < 0.001), prolonged application time (p = 0.007), scrubbing technique (p < 0.001), selective dentin etching (p < 0.001), non-atmospheric plasma (p = 0.01), ethanol-wet bonding (p < 0.01), prolonged blowing time (p = 0.02), multiple layer application (p = 0.005), prolonged curing time (p = 0.006), and hydrophobic layer coating (p < 0.001). On the other hand, the use of a shortened application time (p = 0.006), and dentin desensitizers (p = 0.01) impaired the bond strength of universal adhesives to dentin. Most of the analyses performed showed a high heterogenicity. The in vitro evidence suggests that the application of universal adhesives using some alternative techniques or additional strategies may be beneficial for improving their bonding performance to dentin. This research received no external funding. Considering that this systematic review was carried out only with in vitro studies, registration was not performed.

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

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Effect of Cavity Disinfectants on Dentin Bond Strength and Clinical Success of Composite Restorations-A Systematic Review of In Vitro, In Situ and Clinical Studies

Cavity disinfection becomes an important step before a dental restorative procedure. The disinfection can be obtained cleaning the dental cavity with antimicrobial agents before the use of adhesive systems. The aim of this study was to conduct a systematic review on the effect of different cavity disinfectants on restorations’ adhesion and clinical success. A search was carried out through the Cochrane Library, PubMed, and Web of Science. In vitro and in situ studies reporting results on dentin bond strength tests, and clinical studies published until August 2020, in English, Spanish and Portuguese were included. The methodological quality assessment of the clinical studies was carried out using the Revised Cochrane risk-of-bias tool. Chlorhexidine could preserve adhesion to dentin. EDTA and ethanol had positive results that should be further confirmed. Given the significant lack of scientific evidence, the use of lasers, fluoridated agents, sodium hypochlorite, or other products as cavity disinfectants should be avoided. Chlorhexidine is a safe option for cavity disinfection with adequate preservation of adhesion to dentin. Moreover, future researches should be focused on the efficacy of these disinfectants against cariogenic bacteria and their best application methods.