Comparative evaluation of the effect of chlorhexidine and Aloe barbadensis Miller (Aloe vera) on dentin stabilization using shear bond testing

Influence of different cavity disinfectants on composite adhesion to dentin of primary teeth: An in vitro study

Restorative treatment is the most common approach to treating dental caries. However, after cavity preparation, some microorganisms may still persist in the substrate, suggesting the use of cavity disinfectants. Nevertheless, their effect on adhesion to composite resins is not yet fully understood, especially in primary teeth. The study aimed to assess the impact of five different cavity disinfectants on dentin adhesion in primary teeth. A total of 60 primary molars were uniformly flattened at their occlusal thirds and randomly allocated into six groups (n = 10 each): Control; Glutaraldehyde; Chlorhexidine; EDTA; Ethanol; Aloe vera. All disinfectants were actively applied, rinsed, and air-dried. The adhesion procedure was carried out according to the manufacturer's instructions, and the restoration was positioned using a mold. Shear bond strength was evaluated. Data were statistically analyzed (One-way ANOVA with Post-hoc Tukey test), with the level of significance set at 5 %. Glutaraldehyde (14.59 ± 3.89 MPa), Chlorhexidine (11.24 ± 2.25 MPa), and EDTA (11.04 ± 2.95 MPa) did not impair the shear bond strength when compared to the Control group (14.95 ± 2.75 MPa). Ethanol and Aloe vera application significantly lowered SBS. The results suggest that Glutaraldehyde, Chlorhexidine, and EDTA can be used as cavity disinfectants. Nevertheless, further in vitro and clinical research is required.

Effect of Herbal Intracanal Medicaments on Microhardness of Root Dentin: An In Vitro Study

INTRODUCTION

The use of intracanal medicaments (ICM) is crucial to reduce the microbial load in root canals. However, its application may negatively affect the physical properties of root dentine. Thus, this in vitro study was performed to investigate the effects of different herbal ICM on the microhardness of root dentin.

MATERIALS AND METHODS

A total of 100 mid-root discs were randomly divided into five groups (n = 20) and treated with Aloe vera, Aloe vera + chitosan, curcumin, curcumin + chitosan, and control for 14 days. A Vickers hardness indentation machine (Laizhou Laihua Testing Instrument Factory, Yantai, China) with a load of 200 g and a dwell time of 15 seconds was used for microhardness testing before and after treatment. The results were analyzed using Statistical Product and Service Solutions (SPSS, version 26.0; IBM SPSS Statistics for Windows, Armonk, NY). Intragroup comparisons were executed using paired t-tests, while intergroup comparisons employed ANOVA, followed by post-hoc Tukey's tests.

RESULTS

The Aloe vera + chitosan and curcumin + chitosan groups showed a statistically significant reduction in dentin microhardness (p < 0.05). The decrease in dentin microhardness of the Aloe vera and curcumin groups was non-significant (p > 0.05) and similar to that of the control.

CONCLUSION

Aloe vera or curcumin alone as ICM did not affect the root dentin microhardness. The addition of 0.2% chitosan to either Aloe vera or curcumin negatively affected the root dentin microhardness.

Effect of a novel quaternary ammonium silane based cavity cleanser FiteBac 2% K21 QAS in comparison with other cavity disinfectants on the bond strength of resin-modified glass ionomer cement

Background

The application of cavity cleansers for cavity disinfection can be a crucial step in the longevity of restorations. The objective of the present study was to compare the effect of the application of a new quaternary ammonium silane (QAS)-based cavity cleanser (2% K21 QAS), with other commercially available cavity disinfectants on the bond strength of resin-modified glass ionomer cement (RMGIC).

Materials and Methods

The buccal surfaces of 40 extracted premolars were trimmed to obtain a flat dentinal surface and were randomly divided into four experimental groups depending on the cavity cleansers used before restoration. Group 1: 2% chlorhexidine (CHX), Group 2: QAS (FiteBac 2% K21 QAS), Group 3: silver diamine fluoride-potassium iodide (Riva Star, SDF-KI), and Group 4: 3% hydrogen peroxide (H2O2). Then, a predetermined dimension of RMGIC restoration was bonded to the treated dentin surfaces. Following this, each sample was tested for shear bond strength (SBS) using a universal testing machine at a crosshead speed of 0.5 mm/min.

Results

Among the experimental groups, SDF-KI has shown the highest mean SBS, followed by 2% K21 QAS, and 2% CHX, which have shown almost comparable results. The 3% H2O2 group has shown the lowest values.

Conclusion

According to the results of the present study, 2% K21 QAS has the potential to be used as an effective cavity cleanser before the placement of RMGIC restorations. Since its application does not affect the bond strength of restoration, it can be successfully used as an alternative to CHX and SDF-KI.

Comparative evaluation of fracture resistance among conventional versus herbal irrigants in root canal treated teeth: In vitro study

To evaluate the efficacy of conventional irrigants and herbal extracts materials which helps to resist fracture of endodontically treated teeth. 75 maxillary human permanent incisor teeth instrumented using ProTaper rotary files till apical size(F4). Instrumented samples divided into 5 groups with n = 15 based on various irrigants used. Group I: normal saline, Group II: 5% sodium hypochlorite (NaOCl), Group III: 2% chlorohexidine, Group IV: 10% Azadirachta indica (neem extract) and Group V: 10% Ocimum sanctum (tulsi extract).After that, root canals were proceeded to be filled by using single gutta-percha cone and Sealapex sealer. Specimens were then prepared and loaded until root fracture occurred. Maximum mean flexural strength of dentin (fracture resistance) was obtained from group treated with 2% chlorohexidine and 10% neem extract. Least fracture resistance was observed with 5% NaOCl. Herbal irrigants can be used as an alternative to NaOCl as they exhibit high fracture resistance.

Effect of Different Cavity Disinfectants on Adhesion to Dentin of Permanent Teeth

After the elimination of dental caries lesions, some microorganisms may remain viable in the tooth structure. Thus, cavity disinfection is an important procedure. The aim of this study was to evaluate the effect of cavity disinfectants on the adhesion to dentin of permanent teeth. Sixty molars were ground flat and randomly assigned to six groups: control; chlorhexidine; Aloe vera; glutaraldehyde; EDTA; ethanol. Cavity disinfectants were applied, rinsed, and air-dried. The restorations were performed with the aid of polyethylene tubes. Shear bond strength, work to detachment, and shear modulus were evaluated. All data were statistically analyzed and the level of significance was set at 5%. The control group showed the lowest shear bond strength (8.34 ± 2.68 MPa). Aloe vera showed the lowest work to debonding (2284 J/m²) while chlorhexidine showed the highest (9347 J/m²). Regarding the shear modulus, ethanol, chlorhexidine, and EDTA presented similar values to the control group (216.11 kPa), and glutaraldehyde and Aloe vera presented values twice as high. The use of chlorhexidine, ethanol, EDTA, glutaraldehyde, and Aloe vera did not impair the adhesion established between the dentin of permanent teeth and composite resin. Even though there is a need for clinical studies to support these findings, all disinfectants seem to be good choices as pretreatment agents.

The Comparison of Color Stability of Aloe Vera Gel and Chlorhexidine Solution on Acrylic Teeth

Background

There is insufficient knowledge about aloe vera color change property on acrylic teeth compared to other denture cleaners, especially chlorhexidine solution (CHX).

Objective

The present study aimed to compare the color change property of the aloe vera and chlorhexidine solution on denture acrylic teeth.

Methods

This study was experimental in vitro study design conducted in the dental laboratory of Tabriz University of Medical Sciences, Iran, 2021. The sample size in each group was 21 acrylic teeth which were randomly divided into aloe vera gel 100% and chlorhexidine solution 2% groups. Tooth colors were measured by a spectrophotometer (Spectro Shade Micro, MHT S.P.A., Milan, Italy). The immersion time in both groups was 36 hours. Data analyzed using an independent t-test was used at a 95% of confidence level.

Results

The comparison of the total color differences (ΔE) between the two groups was not statistically significant after 36 hours of immersion (P=0.440). In the chlorhexidine group, the brightness of teeth was lower than that in the aloe vera group (P=0.002).

Conclusions

Clinicians should be aware that aloe vera gel does not change the color of denture acrylic teeth after 36 hours of immersion similar to the chlorhexidine solution. For patients who cannot use chlorhexidine, aloe vera gel is a good cleaner for denture acrylic teeth without worrying about the color change of the denture. It can be considered an acceptable cleaner for denture acrylic teeth.

Effect of Different Mouthwashing Regimens on Adhesion of a Universal Adhesive:A Microshear Bond Strength and Scaning Electron Microscopy Evaluation

Objective: To evaluate the effect of probiotic or chlorhexidine-based mouthwashes and coconut oil pulling therapy on microshear bond strength of a universal adhesive, used with two application modes. Method: Ninety-six enamel specimens were prepared using bovine incisors and the surfaces were grounded. Then the specimens were randomly divided into 4groups and each group were subjected to a mouth washing regimen with one of three agents-chlorhexidine mouthwash, probiotic-based mouthwash, coconut oil pulling – or stored in artificial saliva(control) for 7 days(n=24). After the procedure, all groups were divided into 2 subgroups, and a universal adhesive was applied with etch-and-rinse or self-etch mode(n=12). Composite micro-cylinders were bonded to the enamel surfaces and micro-shear-bond strength was measured after 24hours water storage. Failure modes were determined using a stereomicroscope and SEM analysis was also performed. The data were analyzed using Mann-Whitney-U and Kruskal-Wallis tests. Results: No significant differences were observed between the different mouthwash groups, regardless of application modes(p> .05). There were no significant differences in microshear-bond strength, within the same mouthwash groups, between self-etch or etch-and-rinse modes, except for oil pulling group. Etch-and-rinse group showed higher bond strength than self-etch group in specimens subjected to oil pulling(p< .05). Conclusion: Etch-and-rinse mode might be preferable on patients who practice oil pulling.

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.

Comparative evaluation of effect of chlorhexidine, Azadirachta indica (neem), and Aloe barbadensis miller (Aloe vera) on resin-dentin bond stabilization using shear bond testing: An in vitro study

Introduction:

Cavity disinfectants help to remove the microbial remnants; hence, its use prior to any restoration is valuable, and a search for alternative to chlorhexidine (CHX) is required which may be more efficacious and can overcome the drawbacks of CHX.

Objective:

The aim of this study was to evaluate the effect of application of three different cavity disinfectants in a clinically relevant time period on the immediate and delayed shear bond strengths (SBSs) of an etch-and-rinse adhesive system to dentin.

Materials and Methods:

For SBS testing, flat coronal dentin surfaces were prepared in two hundred extracted human molars. Specimens were randomly assigned to four groups according to the disinfectant used: Group I: Control (no disinfectant), Group II: 2% CHX solution, Group III: Aloe barbadensis miller (Aloe vera) solution, and Group IV: Azadirachta indica (neem) solution. Specimens were bonded using Prime and Bond NT adhesive which was employed according to the manufacturer's instructions. Resin composite cylinder buildups were done in all the samples. The modes of failure were noted after visual examination using a binocular stereomicroscope. Samples were also analyzed under scanning electron microscope for observation of resin-dentin interface. SBS results were analyzed using one-way ANOVA followed by Tukey's post hoc test.

Results:

The results showed that CHX, Aloe vera, and neem had improved bond strengths as compared to the control group for both immediate and delayed SBSs.

Conclusion:

From the results of the study, the authors concluded that Aloe vera and neem can be used as alternative cavity disinfectants to CHX.

Effect of chlorhexidine on the durability of a new universal adhesive system

Background

The effect of chlorhexidine on bond durability of universal adhesives is not clear. The aim of this study was to evaluate the effect of chlorhexidine on 6-month water storage bond strength of adhesive systems.

Material and Methods

72 freshly sound human extracted molars were selected. In each tooth both buccal and lingual sides were prepared by bur to reach superficial dentin and randomly divided into 6 groups and 12 sub-groups and bonded with Scotchbond Universal (SBU) or Scotchbond Multi-purpose (SBMP) with/without chlorhexidine (CHX) usage. Group 1: SBU, group2: SBU+CHX, group3: Etch+SBU, group4: Etch+CHX+SBU, group5: Etch+SBMP, group6: Etch+CHX+SBMP. After composite curing, water storage and thermocycling was done. Each group was divided into two subgroups. One was tested immediately, and the other was thermocycled for 5000 cycles (5-55 °C) (it was equivalent to 6 months of storage in distilled water). Shear bond strength test was done and failure modes were determined by Stereomicroscope. The data were analyzed by one-way ANOVA, Tukey post-hoc test and Paired Two test with P<0.050 as the level of significance.

Results

Shear bond strength in late SBU (Self etch) was significantly lower than late SBU [Etch and rinse (ER)], P value= 0.0001, also shear bond strength in late SBU [self-etch (SE)] was significantly lower than immediate SBU (SE), P value= 0.01. There were no significant differences between other sub-groups and conditions. The most failure mode was adhesive in all the groups.

Conclusions

Long term bonding durability of SBU(ER) was better than SBU (SE). CHX usage had prevented bond strength decrease in SBU and SBMP in long term. CHX usage did not have any effect on immediate shear bond strength of SBU and SBMP. Immediate and late shear bond strength of SBMP with/without CHX usage was similar to SBU(SE, ER). Key words:Dentin Bonding, Shear Bond Strength, chlorhexidine, 6-month storage.

Comparative evaluation of the effect of different disinfecting agents on bond strength of composite resin to dentin using two-step self-etch and etch and rinse bonding systems: An in-vitro study

Objective

This study was carried out to examine the effect of the application of different disinfecting agents on the shear bond strength (SBS) of an etch-and-rinse system.

Materials and Methods

A total of 120 dentin surfaces of human molars were taken. Sixty samples were taken for immediate (testing was done after 24 h) and delayed (testing was done after 6 months) each. Further, they were divided into three subgroups (n = 20) according to the disinfectant used: Group I: control (no disinfectant); Group II: chlorhexidine based; and Group III: Aloe barbadensis miller (Aloe vera) based. Dentine bonding agent was applied, and resin composite build-ups were done for SBS testing. Samples were examined under scanning electron microscope for observing the gap formation for dentin-restoration interface. SBS results were statistically analyzed.

Results

The results of the study showed that both chlorhexidine and aloe vera had improved bond strength as compared to the control group both for immediate and delayed SBSs.

Conclusion

Thus, aloe vera can be used as an alternative to chlorhexidine for cavity disinfection.