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

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.

Evaluation of the Effect of Applying Chitosan, Neem, Tulsi, Aloe vera, and Chlorhexidine Solutions on the Shear Bond Strength of Composite to Dentin

Statement of the Problem

Dentin adhesion is challenging and needs modifications. Newly introduced nature-derived materials may be a useful solution in improving dentin adhesion. The use of natural antimicrobial agents for pretreating prepared dentin surfaces before restoration has become of interest.

Purpose

The present study investigated the effect of natural compounds on the shear bond strength (SBS) of resin composite adhesively bonded to dentin.

Materials and Method

Sixty extracted human molar teeth were randomly divided into six groups (n= 10); Group I: two-step etch and rinse adhesive system, Adper Single Bond 2 (SB2) (experimental control), Group II: 2.5% Chitosan+etch+SB2, Group III: 15% Neem (Azadirachta indica)+etch+SB2, Group IV: 15% Tulsi (Ocimum sanctum)+etch+SB2, Group V: 2% Aloe vera+etch+SB2, and group VI: 2% Chlorhexidine (CHX)+etch+SB2. Resin composite (Z350, 3M ESPE USA) was placed over the prepared dentin surfaces and was light cured. Data analysis was performed using One-way ANOVA and post hoc Tukey's test (p< 0.05).

Results

Neem specimens showed the highest mean SBS, statistically greater than the control (p= 0.042). Other experimental groups showed no significant differences in SBS comparison to the control. The mean SBS values of 2.5% Chitosan, 15% Neem, 15% Tulsi, and 2% Aloe vera were significantly higher than 2% CHX (p= 0.046, p= 0.001, p= 0.010 and p= 0.002 respectively).

Conclusion

Dentin pretreatment with Neem may improve the bond strength of a two-step etch and rinse adhesive system. The application of Chitosan, Tulsi, Aloe vera, and CHX did not demonstrate significantly different SBS values from that of the Control, although CHX was lower.

Antimicrobial efficacy of 2% chlorhexidine gel, triphala, and Azadirachta indica as intracanal medicaments against Enterococcus faecalis: A randomized clinical trial

Context

Concerns about adverse reactions and the development of antibiotic resistance have prompted an alternative treatment strategy that utilizes traditional medicinal herbs.

Aim

This randomized control trial assessed the antimicrobial efficacy of 2% chlorhexidine (CHX) gel, Triphala, and Azadirachta indica as intracanal medicaments against Enterococcus faecalis.

Materials and Methods

Forty patients with nonvital teeth and single root canals were selected (n = 10). Following the initial access opening, the first microbial samples (S1) were collected using paper points. Second microbial samples (S2) were collected following the chemo-mechanical preparation and 1 week after introducing the intracanal medicaments. Group I: 2% CHX, Group II: A. indica, Group III: Triphala, and Group IV: Calcium hydroxide (Ca(OH)2). S1 and S2 samples were collected, and bacterial growth was observed using the colony-forming unit (CFU) count.

Statistical Analysis

Comparison of the difference in CFU count among four groups was performed using one-way ANOVA test (P < 0.05) followed by post hoc Tukey test.

Results

Reduction in CFU count postmedication S2 from S1 in each group was statistically significant. Percentage reduction in CFU count was highest in Triphala group followed by A. indica and 2% CHX group. Percentage reduction in CFU count was least in Ca(OH)2 group. The post hoc pairwise comparison of % reduction in CFU count among four groups showed that the percent reduction was highest in Triphala group.

Conclusion

Triphala has considerable antimicrobial efficacy against E. faecalis.

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.

Evaluation of Aloe vera as matrix metalloproteinase inhibitor in human dentin with and without dentin-bonding agent: An in vitro study

Background:

Proper hybrid layer formation lays the foundation of resin–dentin bonding. The resin infiltration in demineralized dentin collagen couples with the adhesive/resin composites in the mineralized dentin surface. However, the activation of enzymatic activity in the collagen matrix can degrade the hybrid layer. Over the time, it leads to reduced bond strength. Mainly, the enzymes involved are matrix metalloproteinases (MMPs) which are involved in degrading most of the extracellular matrix components. Aloe vera is an herb with an anti-inflammatory effect, but its role in human dentin as an enzyme inhibitor has not been verified yet.

Aims:

The purpose of the study was designed for evaluating the inhibitory action of Aloe vera on MMP in human dentin with and without dentin bonding agents.

Materials and Methods:

A total of 15 freshly extracted healthy human teeth were collected and stored at 4°C until use. The roots were separated. The enamel and remnant pulp tissue were removed, and collected teeth were pulverized with liquid nitrogen in the minimum volume of 50-mM phosphate buffer to obtain dentin powder extract. The dentin powder extract is the source of MMPs, and therefore, the extract was treated with A. vera solution and incubated to assess the enzyme inhibition by the plate assay method and zymographic analysis.

Results:

A. vera treated sample with and without dentin bonding agent showed inhibition of dentin MMP's activity by plate assay method and confirmed by zymogram analysis.

Conclusions:

A. vera has the potential for inhibiting the MMPs enzyme activity of human dentin collagen with and without dentin bonding agents.