The antimicrobial effect of different vitamin D compounds on Streptococcus mutans and their impact on glycosyltransferase expression.

Background: Streptococcus mutans is a virulent microorganism associated with dental caries. This in vitro study aimed to investigate the antimicrobial effects of Cholecalciferol (D3) and Doxercalciferol (D2), against S. mutans and on glycosyltransferase gene expression. Methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of D3 and D2 for S. mutans were determined according to the Clinical Laboratory Standards Institute guidelines. The effect of the compounds on environmental pH in 1% w/v and 5% w/v sucrose broth cultures after 24 hours were assessed colorimetrically. Additionally, their impact on glycosyltransferases gene expression (GtfB, GtfC, GtfD) in 5% w/v sucrose culture was evaluated using quantitative real-time PCR. Results: The MBCs of D3 and D2 were 83 µg/ml and 166 µg/ml respectively. Both compounds were effective in preventing the local pH drop <5.5 at ≥166 µg/ml in sucrose supplemented cultures. However, the compounds did not inhibit pH drop at MIC values. Notably, D2 upregulated GtfD expression significantly (p < 0.05) and downregulated GtfB and GtfC. Conclusion: Vitamin D2 and D3 inhibited S. mutans mediated pH drop in sucrose supplemented cultures and altered glycosyltransferase expression, suggesting potential therapeutic roles in dental caries prevention. Further research is needed to assess their full impact on S. mutans survival under environmental stresses.

The effect of different concentrations of fluoride in toothpastes with or without bioactive glass on artificial root caries.

OBJECTIVE: To investigate the effect of different toothpastes either containing 5,000ppm-F, 1,450ppm-F or bioactive glass (BG) with 540ppm-F on artificial root carious lesions (ARCLs). METHOD: The crowns of 23 extracted sound teeth were removed leaving their roots only. Subsequently, each root was divided into four parts. A total of 15 sound root dentine (SRD) was left untreated as baseline. The ARCLs were developed for the remaining roots using demineralisation solution (pH-4.8). 15-ARCLs samples were then left untreated. The rest of samples were divided into four groups (n = 15 each) and treated with Group-1(BG with 540ppm-F); Group-2(5000ppm-F); Group-3(1450ppm-F) and Group-4(deionised water). 13-day pH-cycling included using demineralisation solution for 6 h, then placing samples into remineralisation solution (pH-7) for 16 h. Each sample was brushed with the assigned toothpaste twice a day during pH-cycling. Fluoride concentrations at each time point were measured using F-ISE, whilst calcium (Ca2+) and phosphorus (P) ion release was determined using ICP-OES, KHN, XRD, 19F-MAS-NMR analyses. RESULTS: KHN showed significant surface changes for each group (p<0.001). The uptake of Ca2+ occurred at days 1-2, phosphorus ion loss was high when compared to the uptake in all groups. XRD showed presence of sharp diffraction lines evidencing apatite formation for Groups 1-3. 19F-MAS-NMR confirmed fluorapatite presence in Groups 1-3. CONCLUSION: All toothpastes were promising in fluorapatite formation. BG with 540ppm-F toothpaste released more ions (Ca2+and P) and reharden the artificial root carious lesions when compared to other groups. However, 1450ppm-F toothpaste showed more fluoride-substituted apatite formation whilst 5000ppm-F toothpaste had more fluorapatite formation. CLINICAL SIGNIFICANCE: Toothpaste containing BG with 540ppm-F, 5000ppm-F and 1450ppm-F toothpastes are likely to have a significant impact in reversing and arresting root caries. However, randomised controlled double-blinded clinical trials are required to translate these results into clinical practice.

Effects of ozone and ND:YAG laser pretreatment on bond strength of self-etch adhesives to coronal and root dentin.

OBJECTIVES: The aim of this study was to evaluate the effects of two different disinfection treatments--ozone and Nd:YAG laser application--on shear-bond strength (SBS) of self-etch adhesives to coronal and root dentin. MATERIALS AND METHODS: Sixty extracted human canines were ground flat, exposing the coronal and root dentin surfaces, and randomly divided into three groups. The surfaces were untreated (Control) or treated with ozone (HealOzone, KaVo) or Nd:YAG laser (Fidelis III, Fotona). Coronal and root dentins of 10 teeth of each group were treated with a two-step self-etch adhesive (Clearfil SE Bond, Kuraray Medical; SE), whereas the remaining 10 teeth were treated with a one-step self-etch adhesive (Clearfil Tri-S Bond, Kuraray Medical; S3). A resin composite (Clearfil Majesty Esthetics, Kuraray Medical) was then placed, and SBS was tested with a universal testing machine. Failure modes were determined under a stereomicroscope. The mean SBS values of each group were calculated, and data were subjected to statistical analysis (p = 0.05). RESULTS: For the coronal dentin, Control/SE showed significantly higher values than Control/S3, Ozone/S3, and Nd:YAG/S3. Although Ozone/SE showed significantly higher values than Nd:YAG/S3 (p < 0.05), the differences within the other groups were not significant for the root dentin (p > 0.05). Comparison of two dentin substrates in each group did not show any significant difference except for Control/SE, in which coronal dentin showed higher SBS. The failure modes of all groups were mainly adhesive. CONCLUSION: Pretreatments with Ozone or Nd:YAG laser did not impair the SBS of both of the self-etch adhesives used to coronal and root dentin.

Clinical reversal of root caries using ozone: 6-month results.

PURPOSE: To assess the safety and efficacy of ozone either with or without a root sealant, for the management of leathery root caries. METHODS: 79 subjects with 220 root caries lesions were recruited into four study groups in this randomized, controlled trial. At baseline and after 1, 3, and 6 months, the ECM III and DIAGNOdent were employed. Subsequently, the root caries lesions were clinically assessed for color, hardness, cavitation, dimensions, distance from the gingival margin, and severity index. Modified USPHS criteria were also performed after 1, 3, and 6 months. These groups were as follows: Group 1: Ozone application was performed for a period of 10 seconds on caries lesions; Group 2: There was neither ozone nor root sealant application on root caries; Group 3: Ozone treatment and a root sealant were applied to root caries lesions; and Group 4: Only root sealant was applied to root caries. RESULTS: At the 6-month recall, 78 subjects were examined. There were no observed adverse events. 38.1% of lesions became hard in the ozone only group, while none of the lesions became hard in the control group (P< 0.001). Noncavitated lesions were more likely to reverse than cavitated lesions. 38.4% of noncavitated lesions became hard, while only 5.7% of cavitated lesions became hard in the ozone only group. Modified USPHS criteria revealed that there were 66.6% intact sealants in the ozone and sealant group and 45.5% intact sealants in the sealant only group (P< 0.05). After 1, 3, and 6 months, the ECM and DIAGNOdent readings showed improvements in the ozone only group when compared to the control group (P< 0.001). The ozone and sealant group also had greater improvements in the ECM and DIAGNOdent values when compared to the sealant only group (P< 0.05).

The use of ozone in dentistry and medicine. Part 2. Ozone and root caries.

A previous paper, recently published in Primary Dental Care, gave an overview of the medical uses of ozone and outlined some of its uses in dentistry. The current paper focuses on a description of use of ozone in the management of root caries and considers recent studies in this area. There has been relatively limited research into the non-invasive (pharmaceutical) management of root caries. The best management strategy still remains to be developed. Initial studies have indicated that an application of ozone for a period of either 10 or 20 seconds is capable of clinically reversing leathery root carious lesions. It is suggested that, subject to confirmation from extensive trials, this simple and non-invasive technique may benefit many patients with root caries throughout the world since this approach to treat root caries can easily be employed in primary care clinics and in the domiciliary treatment of home-bound elderly people and immobile patients in hospices and hospitals.