Effect of Cavity Disinfectants on Adhesion to Primary Teeth-A Systematic Review

Effectiveness of plant-mediated synthesis of hydroxyapatite nano-particles impregnated in Pistachio oleogum resin on mineral contents of human teeth. An in-situ single-blind controlled study

OBJECTIVES

This study aimed to synthesize and characterize an environmentally friendly nanohydroxyapatite (n-HA) and evaluate its impact on enamel mineral content when incorporated into a Pistachio oleo gum resin (Saqqez) bio-chewing gum for in-situ models. We compared the effects of this green nano-hydroxyapatite (G n-HA) with those of a commercially available synthetic nano-hydroxyapatite (S n-HA).

METHODS

Various analytical techniques were employed including XRD, FESEM, FT-IR, EDX/SEM and TGA/DTA to characterize the crystallinity, size and composition of the G n-HA powder. Three chewing gum groups were formulated: (1) Saqqez gum containing 10% wt G n-HA, (2) Saqqez gum containing 10% wt S n-HA, and (3) pure Saqqez gum. In order to evaluate the impact of these chewing gums on enamel, intraoral appliances were fabricated, each containing six enamel specimens. Participants were instructed to chew the gums while wearing these appliances. The calcium (Ca+2) and phosphorus (P) levels in enamel specimens, both with and without exposure to an acid challenge, were quantified using EDX/SEM. FE-SEM was employed to capture the microstructure of the enamel surface. In terms of the statistical analysis, one-way ANOVA and Tukey's post hoc tests were utilized to compare the data, where the significance level (α) was set at 0.05.

RESULTS

The characterization tests confirmed the successful synthesis of G n-HA. Furthermore, EDX/SEM analysis of the enamel specimens from the intraoral appliance revealed significant variations in calcium (Ca+2) content among the enamel specimens (P = 0.000). The S n-HA group, in particular, exhibited the highest Ca+2 content, while the pure Saqqez group displayed the lowest. Nonetheless, there was no statistically significant differences in phosphorus (P) content observed among the three groups (P = 0.27).

CONCLUSIONS

Saqqez gum can be considered a wholesome natural chewing gum that serves, as a carrier for delivering remineralization agents to the tooth surfaces. This was evident in the groups containing n-HA, exhibiting elevated Ca+2 levels. It's noteworthy that G n-HA demonstrated less efficacy in enamel remineralization compared to S n-HA.

Comparative evaluation on the effect of different cavity disinfectant nano gels; Chlorohexidine, Propolis, Liquorice versus Diode Laser in terms of composite microleakage (comparative in vitro study)

INTRODUCTION

The application of different cavity disinfectants is an essential step that eliminates bacteria after cavity preparation. However, some of these materials may affect restoration sealing ability.

AIM

This study aimed to assess the degree of microleakage at the tooth restoration interface after using different nano prepared cavity disinfectants versus Diode Laser.

MATERIALS AND METHODS

Three disinfectants were prepared on the nanoscale; Propolis, Liquorice and Chlorhexidine. A total of 40 extracted premolars with standard class V cavities were prepared on the facial surface. Teeth were divided into five groups according to the applied cavity disinfection protocol; no treatment, Chloehexidine, Propolis, Liquorice, and Diode Laser. After application of composite resin restoration, all teeth were subjected to thermocycling, afterwords the degree of microleakage was measured in micrometers. Data were analyzed by one-way analysis of variance (ANOVA) test, followed by Bonferroni's and Tukey's post hoc test.

RESULTS

The highest mean microlekage value was recorded in no treatment group, followed by Liquorice, Propolis. While Diode Laser group showed the lowest degree of microleakage.

CONCLUSION

Diode Laser cavity disinfectant has no negative effect on the restoration sealing ability. Nano prepared Propolis showed comparative results to nanoChloehexidine as both had low degree of microleakage.

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.

Influence of 2% Chlorhexidine on the Bond Strength of Three Adhesive Systems on Primary Molars: An In Vitro Study

The hydrolysis of the collagen matrix by metalloproteinases (MMPs) is one of the paradigms that currently arouses most interest due to its close relationship with a decrease in bond strength (BS) and consequent restoration failure. Chlorhexidine 2% has demonstrated its ability to inhibit MMPs’ activity in the permanent dentition, improving the duration of resin–dentine, but there are few studies on deciduous dentition and its possible repercussions. Aim: To determine the influence of 2% chlorhexidine digluconate (CHX) as a dentine pretreatment on the BS of three adhesive systems on primary molars. Methods: 128 primary extracted molars were assigned to eight groups at random. BS in vitro was recorded by micropush-out test, and analyzed by two-way ANOVA. Results: BS values oscillated from 15.01 MPa to 20.41 MPa. There was no statistically relevant variation between the BS total mean of those adhesive groups that had received CHX pretreatment versus those that did not. Adper Prompt L-Pop was the self-etching adhesive with the best BS. Adper Scotchbond 1XT was the total-etch adhesive with the best BS values. Conclusions: Application of 2% chlorhexidine for 60 s as dentine pretreatment did not affect the immediate BS of several adhesive systems used in primary dentition.

Chlorhexidine gluconate enhances the remineralization effect of high viscosity glass ionomer cement on dentin carious lesions in vitro

Background

To compare the mean mineral density (MMD) and examine the remineralization of carious dentin after cavity disinfection with chlorhexidine gluconate (CHX) and restoration with high viscosity glass ionomer cement (H-GIC) in vitro.

Methods

Selective caries removal to leathery dentin was performed in 40 extracted primary molars. The samples were scanned using micro-computed tomography (micro-CT) to determine the MMD baseline and randomly divided into 4 groups (n = 10): Equia™ group, applied dentin conditioner and restored with H-GIC (Equia Forte™), CHX-Equia™ group, disinfected the cavity with 2% CHX before applying dentin conditioner and restored with H-GIC (Equia Forte™), Ketac™ group, restored with H-GIC (Ketac Universal™) and CHX-Ketac™ group, disinfected the cavity with 2% CHX before restored with H-GIC (Ketac Universal™). The samples underwent micro-CT scanning post-restoration and post-pH-cycling to determine their respective MMDs. One sample from each group was randomly selected to analyze by scanning electron microscopy (SEM).

Results

The MMD gain in the 4 groups post-restoration was significantly different between the Equia™ and CHX-Ketac™ groups (oneway ANOVA with Post hoc (Tukey) test, P = 0.045). There was a significant difference in MMD gain post-restoration between the Equia™ and CHX-Equia™ groups (Independent t-test, P = 0.046). However, the Ketac™ and CHX-Ketac™ group’s MMD were similar. The SEM images revealed that the CHX-Ketac™ group had the smallest dentinal tubule orifices and the thickest intertubular dentin among the groups. However, the CHX-Equia™ group had thicker intertubular dentin than the Equia™ group.

Conclusion

Applying 2% CHX on demineralized dentin enhances the remineralization of the dentin beneath the restoration.

A Chitosan-Agarose Polysaccharide-Based Hydrogel for Biomimetic Remineralization of Dental Enamel

Developing multifunctional systems for the biomimetic remineralization of human enamel is a challenging task, since hydroxyapatite (HAP) rod structures of tooth enamel are difficult to replicate artificially. The paper presents the first report on the simultaneous use of chitosan (CS) and agarose (A) in a biopolymer-based hydrogel for the biomimetic remineralization of an acid-etched native enamel surface during 4–10-day immersion in artificial saliva with or without (control group) fluoride. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, Fourier transform infrared and Raman spectroscopies, X-ray diffraction, and microhardness tests were applied to investigate the properties of the acid-etched and remineralized dental enamel layers under A and CS-A hydrogels. The results show that all biomimetic epitaxial reconstructed layers consist mostly of a similar hierarchical HAP structure to the native enamel from nano- to microscale. An analogous Ca/P ratio (1.64) to natural tooth enamel and microhardness recovery of 77.4% of the enamel-like layer are obtained by a 7-day remineralization process in artificial saliva under CS-A hydrogels. The CS component reduced carbonation and moderated the formation of HAP nanorods in addition to providing an extracellular matrix to support growing enamel-like structures. Such activity lacked in samples exposed to A-hydrogel only. These data suggest the potential of the CS-A hydrogel in guiding the formation of hard tissues as dental enamel.