In vitro evaluation of fluoride and calcium sodium phosphosilicate toothpastes, on root dentine caries lesions

Frontiers of Global Research Trend on Root Caries: A Bibliometric Analysis

OBJECTIVE

This study aimed to examine the global research trend and frontiers in the field of root caries.

METHODS

Two independent investigators searched the Web of Science Core Collection to include journal articles published on root caries from 1994 to 2023. They examined citation trends of the selected publications and performed bibliometric analysis using VOSviewer. Cooccurrence and cocitation analysis were used to calculate the burst strength of the most cited keywords and the most cited publications.

RESULTS

This study included 1144 publications (1004 scientific research articles and 140 review articles) for bibliometric analysis. The number of publications from 2018 to 2023 was 404, accounting for 35% (404/1144) over the last 30 years. The annual citation count showed a gradual upward trend with a surge from 2018. The cooccurrence analysis classified the publications into four clusters which were in vitro studies, prevention, microbiology, and epidemiology. Cocitation analysis revealed silver diamine fluoride, systematic review, and randomized clinical trial were the three main keywords; and their citation burst strength (period) were 17.2 (2017-2023), 9.4 (2015-2023), and 6.9 (2018-2023), respectively. Noninvasive treatment of root caries (narrative review), aetiology of root caries (narrative review), and use of silver diamine fluoride in arresting root caries (clinical trial) were the topics (publication type) of the three most cited publications; and their burst strength (period) were 8.9 (2017-2020), 5.9 (2017-2021), and 4.7 (2015-2018), respectively.

CONCLUSION

This study highlights the recent growing research interest in root caries, particularly on its microbiology, prevention, and the use of silver diamine fluoride.

Inhibitory effect of Salvadora persica extract (Miswak) on collagen degradation in demineralized dentin: In vitro study

Background/purpose

Root dentin is vulnerable to acid attack, suggesting a higher risk of demineralization than coronal enamel. This study aimed to evaluate the inhibitory effect of Miswak extract on collagen degradation of demineralized dentin lesion.

Materials and methods

Demineralized bovine root dentin specimens were treated for 1 h by 20% Miswak extract and 0.12% Chlorehexidine (CHX) as a positive control group, and then subjected to collagenolytic attack (clostridium histolyticum 0.5 CDU/mL, 16 h). These cyclic treatments were repeated for 3 days. After the cyclic treatment, the images of the specimens were captured with a light microscope and the lesion depth of degraded collagen layer of all specimens was measured. The mean lesion depth was calculated and compared between the groups using descriptive and One-way ANOVA followed by Post hoc Tukey's tests. Significant level was set at p < 0.05.

Results

The mean lesion depth of CHX (28.6 ± 3.37 μm) had the least value, followed by Miswak (37.5 ± 4.01 μm) then the control (78.4 ± 18.43 μm) group. There was a significant difference in the mean lesion depth among the three groups (p = 0.000).

Conclusion

Miswak aqueous extract from S. persica was found to preserve the dentin collagen matrix from collagenase enzyme. This could be due to the organic compounds like flavonoids, saponins, alkaloids, tannins, and others which have been reported in literature. Present finding suggests that Miswak might play a positive effect in dentin caries prevention.

Is there evidence for Novamin application in remineralization?: A Systematic review

Background

Calcium sodium phosphor-silicate material, a type of bio-glass was originally developed as an implant material to regenerate bone and recently adapted for use in oral care products (NovaMin Technology Inc.). Novamin is used for many dental problems like hypersensitivity, gingivitis, bleeding, non-carious lesions, carious lesions, whitening and is currently emerging as one of the treatment modality for the remineralization of the tooth. Since the prescription of these novel materials to the patients are based on cost effectiveness, efficacy and effectiveness, a clinician should make decision based on best available evidence. Hence, the objective of this review is to find out the current evidence available on the use of Novamin as an agent for remineralization.

Materials and methods

Relevant articles were searched and screened from several databases including PubMed, Cochrane review, Science Direct and trip which were published till 1988 to July 2017; The articles relevant to the objective of this review were included (RCT's) and articles out of interest of this review were excluded. The primary outcome for the chosen studies is the remineralization capacity of Novamin. Data extraction is done independently and jointly by 3 authors using data collection forms. Studies obtained were evaluated using the Cochrane Collaboration tools for accessing risk bias. The assessment of the quality of the evidence and the bias risk was obtained using the Grading of Recommendations Assessment Development and evaluation System.

Results

The articles from the database obtained for further review was N = 1. According to the study reviewed, the baseline comparisons using decalcification index obtained between Novamin study group (ReNew) and the control group (Crest) yield a P-value of 0.97 whereas after a 3 months interval follow up the value is 0.0403 suggesting there was a trend towards improvement in white spot lesions in the control group and at 6 months' time point the p-value is 0.81 concluding that there are no significant difference of remineralization process obtained by using traditional toothpaste and Novamin.

Conclusion

Review shows that Novamin has significantly less clinical evidence to prove its effectiveness as a remineralization agent in treating both carious and non-carious lesion. Hence, better designed clinical trials should be carried out in the future before definitive recommendations can be made.

Effects of Dentifrices Differing in Fluoride Content on Remineralization Characteristics of Dentin in vitro

OBJECTIVES

The aim of this study was to compare the caries preventive effect of highly fluoridated dentifrices and gels on sound dentin as well as on artificial dentin caries-like lesions.

METHODS

Bovine dentin specimens (n = 240), with 2 different surfaces each (1 sound surface [sound treatment (ST)] and one caries lesion [demineralized treatment (DT)]), were prepared and randomly allocated to one highly (6 × 120 min demineralization/day [H]) and one lowly cariogenic (6 × 60 min demineralization/day [L]) pH-cycling model. Treatments during pH-cycling (28 days) were: brushing 2×/day with: 0 ppm F [H0/L0], 1,450 ppm F [H1,450/L1,450], 2,800 ppm F [H2,800/L2,800], 5,000 ppm F [H5,000/L5,000], 5,000 ppm F plus TCP [H5,000+TCP/L5,000+TCP], and 12,500 ppm F [H12,500/L12,500] containing dentifrices/gels. Dentifrice/gel slurries were prepared with deionized water (1:2 wt/wt). Differences in integrated mineral loss (∆∆Z) and ∆ lesion depth were calculated between values before and after pH-cycling using transversal microradiography.

RESULTS

The correlation between ΔΔZDT and F- was strong for the highly (rH = 0.691; p < 0.001) and moderate (rL = 0.500; p < 0.001) for the lowly cariogenic model, indicating a fluoride dose-response for both. Significant differences for ΔΔZDT and ΔΔZST could be found between H0, H1,450, H5,000, and H12,500 as well as L0, L5,000, and L125,000 (p ≤ 0.046; analysis of covariance [ANCOVA]). Except for 0 ppm F-, no significant difference in ΔΔZST and ΔΔZDT could be found between the highly and lowly cariogenic model (p ≥ 0.056; ANCOVA).

CONCLUSION

For both pH-cycling conditions a dose-response for fluoride could be revealed. For elderly people with exposed root surfaces, the use of gels containing 12,500 ppm F instead of regularly (1,450 ppm F) or highly (5,000 ppm F) fluoridated dentifrices should be further investigated, as it offered higher caries-preventive effects in vitro.

Effect of 10% fluoride on the remineralization of dentin in situ

Objective The purpose of this randomized, cross-over, in situ study was to determine the remineralization of demineralized dentin specimens after the application of a 10% fluoride (F-) or a 1% chlorhexidine-1% thymol (CHX-thymol) varnish. Material and Methods Twelve individuals without current caries activity wore removable appliances in the lower jaw for a period of four weeks. Each appliance contained four human demineralized dentin specimens fixed on the buccal aspects. The dentin specimens were obtained from the cervical regions of extracted human third molars. After demineralization, half the surface of each specimen was covered with a nail varnish to serve as the reference surface. The dentin specimens were randomly assigned to one of the three groups: F-, CHX-thymol, and control (no treatment). Before the first treatment period and between the others, there were washout periods of one week. After each treatment phase, the changes in mineral content (vol% µm) and the lesion depths (µm) of the dentin slabs were determined by transverse microradiography (TMR). Data analysis was accomplished by the Kruskal-Wallis test and the Mann-Whitney U test (p<0.05). Results The medians (25th/75th percentile) of integrated mineral loss were 312.70 (203.0-628.7) for chlorhexidine varnish, 309.5 (109.8-665.8) for fluoride varnish, and -346.9 (-128.7 - -596.0) for the control group. The medians (25th/75th percentile) of lesion depth were 13.6 (5.7-34.5) for chlorhexidine varnish, 16.5 (5.6-38.1) for fluoride varnish, and -14.2 (-4.5- -32.9) for the control group. Use of the 10% F- or 1% CHX-1% thymol varnishes resulted in significantly decreased mineral loss and lesion depth in dentin when compared with the control group. There were no statistically significant differences among the test groups. Conclusions Within the limitations of this study, the results suggest that the effect of the treatment of demineralized dentin with 10% F- or 1% CHX-1% thymol is better than without any treatment.

Development of a multifunctional adhesive system for prevention of root caries and secondary caries

OBJECTIVES

The objectives of this study were to: (1) develop a novel adhesive for prevention of tooth root caries and secondary caries by possessing a combination of protein-repellent, antibacterial, and remineralization capabilities for the first time; and (2) investigate the effects of 2-methacryloyloxyethyl phosphorylcholine (MPC), dimethylaminohexadecyl methacrylate (DMAHDM), and nanoparticles of amorphous calcium phosphate (NACP) on dentin bond strength, protein-repellent properties, and dental plaque microcosm biofilm response.

METHODS

MPC, DMAHDM and NACP were added into Scotchbond Multi-Purpose primer and adhesive. Dentin shear bond strengths were measured. Adhesive coating thickness, surface texture and dentin-adhesive interfacial structure were examined. Protein adsorption onto adhesive resin surface was determined by the micro bicinchoninic acid method. A human saliva microcosm biofilm model was used to investigate biofilm metabolic activity, colony-forming unit (CFU) counts, and lactic acid production.

RESULTS

The resin with 7.5% MPC+5% DMAHDM+30% NACP did not adversely affect dentin shear bond strength (p>0.1). The resin with 7.5% MPC+5% DMAHDM+30% NACP produced a coating on root dentin with a thickness of approximately 70μm and completely sealed all the dentinal tubules. The resin with 7.5% MPC+5% DMAHDM+30% NACP had 95% reduction in protein adsorption, compared to SBMP control (p<0.05). The resin with 7.5% MPC+5% DMAHDM+30% NACP was strongly antibacterial, with biofilm CFU being four orders of magnitude lower than that of SBMP control. Significance The novel multifunctional adhesive with strong protein-repellent, antibacterial and remineralization properties is promising to coat tooth roots to prevent root caries and secondary caries. The combined use of MPC, DMAHDM and NACP may have wide applicability to bonding agents, cements, sealants and composites to inhibit caries.

Preventive effect of different toothpastes on enamel erosion: AFM and SEM studies

The aim of the present in vitro study was the evaluation of new formulation toothpastes on preventing enamel erosion produced by a soft drink (Coca Cola), using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Fifty enamel specimens were assigned to 10 groups of 5 specimens each. 1: intact enamel, 2: enamel + soft drink, 3: intact enamel + BioRepair Plus-Sensitive Teeth, 4: enamel + soft drink + BioRepair Plus-Sensitive Teeth, 5: intact enamel + BioRepair Plus-Total Protection, 6: enamel + soft drink + BioRepair Plus-Total Protection, group 7: intact enamel + Sensodyne Repair & Protect, 8: dentin + soft drink + Sensodyne Repair & Protect, 9: intact dentin + Colgate Sensitive Pro Relief, 10: dentin + soft drink + Colgate Sensitive Pro Relief. The surface of each specimen was imaged by AFM and SEM. The root mean-square roughness (Rrms ) was obtained from the AFM images and the differences in the averaged values among the groups were analyzed by ANOVA test. Comparing groups 4, 6, 8, 10 (soft drink + toothpastes) Colgate Sensitive Pro Relief promoted enamel remineralization, while BioRepair Plus-Sensitive Teeth, Biorepair Plus-Total Protection and Sensodyne Repair & Protect provided lower effectiveness in protecting enamel against erosion.

SIGNIFICANCE

the use of new formulation toothpastes can prevent enamel demineralization.

The effect of a bioglass paste on enamel exposed to erosive challenge

OBJECTIVES

The current study is evaluating the effect of using a 45S5 bioglass paste and topical fluoride application on the cross sectional micro-hardness and the chemical surface changes of eroded enamel.

METHODS

Enamel discs were obtained from the buccal surface of one hundred extracted human non-carious third molars. The enamel surfaces were ground flat and each disc was coated with two layers of acid resistant nail varnish except for an exposed treatment window (3mm×2mm) on the buccal surface of the tooth. All specimens were challenged for 60 min by orange juice (Tropicana, Chicago, USA) pH 3.85+0.5. The specimens were divided into four groups: the 45S5 bioglass paste group, fluoride gel group (5 min application), fluoride gel group (24h application) while the rest of specimens served as control. The cross-sectional micro-hardness of 20 specimens from each group was measured. Five specimens from each group had their top eroded enamel surfaces examined by SEM-EDS. One-way ANOVA was used to compare the cross-sectional micro-hardness of the three groups p<0.05.

RESULTS

45S5 bioglass paste application significantly improved the sub-surface eroded enamel when compared to fluoride and control specimens (p<0.05).

CONCLUSION

45S5 bioglass paste can efficiently improve the micro-hardness of the sub-surface eroded enamel surface.

CLINICAL SIGNIFICANCE

The use of the 45S5 Bioglass paste can be used efficiently as a potent remineralizing agent for the sub-surface enamel lesions resulting from erosive challenges.