Effect of a single application of silver diamine fluoride on root caries after 12 months in institutionalised older adults-A randomised clinical trial.

OBJECTIVE: Silver diamine fluoride (SDF) has been shown to be highly effective against caries, in particular for arresting root surface caries and for dentine caries in primary teeth. SDF may complement fluoride varnish routines for treatment of root caries in nursing home residents. The aim of this randomised, single-blinded, placebo-controlled trial was to evaluate the additive effect of a single annual application of SDF for prevention and treatment of incipient root caries in older adult nursing home residents. METHOD: Four hundred older adult nursing home residents (≥70 years old) with at least one exposed root surface (on teeth 15, 14, 13, 23, 24, or 25) were identified during routine dental examination visits in the domiciliary dental care setting. Eligible patients, who were able to understand the implication of consenting to the study, were invited to participate. Their cleaned root surfaces were randomly allocated to treatment with SDF (Advantage Arrest Silver Diamine Fluoride 38%, Advantage Arrest, LLC, Redmond, OR 97756, USA, Lot 16 152) or with placebo (tap water), each for 1 minute. RESULTS: Of the 400 eligible individuals, 42 declined to participate and two forms were destroyed. The remaining 356 participants (89.0%; mean age 87.7 years) were randomly allocated, with 174 going to the SDF group and 182 to the placebo group. At 1 year, 273 participants (76.7%) were available for assessment: 135 in the SDF group and 138 in the placebo group. By that time, 109 individuals (39.9%) demonstrated root caries progression or regression. Among those 118 (16.7%) of the 708 included root surfaces had developed caries There were no statistically significant differences in the primary outcome related to treatment with SDF or placebo, at either patient or root surface level. CONCLUSION: Based on the finding of this clinical trial, it is concluded that a single SDF application to complement a risk-based preventive programme including fluoride varnish applications did not have a statistically significant additional preventive effect on root caries development in a group of older adult nursing home residents with limited caries activity and cognitive capacity to cooperate in oral care activities.

Development of a Root Caries Prediction Model in a Population of Dental Attenders.

Root caries prevalence is increasing as populations age and retain more of their natural dentition. However, there is generally no accepted practice to identify individuals at risk of disease. There is a need for the development of a root caries prediction model to support clinicians to guide targeted prevention strategies. The aim of this study was to develop a prediction model for root caries in a population of regular dental attenders. Clinical and patient-reported predictors were collected at baseline by routine clinical examination and patient questionnaires. Clinical examinations were conducted at the 4-year timepoint by trained outcome assessors blind to baseline data to record root caries data at two thresholds - root caries present on any teeth (RC > 0) and root caries present on three or more teeth (RC ≥ 3). Multiple logistic regression analyses were performed with the number of participants with root caries at each outcome threshold utilized as the outcome and baseline predictors as the candidate predictors. An automatic backwards elimination process was conducted to select predictors for the final model at each threshold. The sensitivity, specificity, and c-statistic of each model's performance was assessed. A total of 1,432 patient participants were included within this prediction model, with 324 (22.6%) presenting with at least one root caries lesion, and 97 (6.8%) with lesions on three or more teeth. The final prediction model at the RC >0 threshold included increasing age, having ≥9 restored teeth at baseline, smoking, lack of knowledge of spitting toothpaste without rinsing following toothbrushing, decreasing dental anxiety, and worsening OHRQoL. The model sensitivity was 71.4%, specificity 69.5%, and c-statistic 0.79 (95% CI: 0.76, 0.81). The predictors included in the final prediction model at the RC ≥ 3 threshold included increasing age, smoking, and lack of knowledge of spitting toothpaste without rinsing following toothbrushing. The model sensitivity was 76.5%, specificity 73.6%, and c-statistic 0.81 (95% CI: 0.77, 0.86). To the authors' knowledge, this is the largest published root caries prediction model, with statistics indicating good model fit and providing confidence in its robustness. The performance of the risk model indicates that adults at risk of developing root caries can be accurately identified, with superior performance in the identification of adults at risk of multiple lesions.

Arrest of root caries with an adjuvant chlorhexidine-fluoride varnish over a 12-months observation period: a QLF-analyzed, placebo-controlled, randomized, clinical trial (RCT).

This study aimed at evaluating the effectiveness of an adjuvant chlorhexidine-fluoride varnish (Cervitec F) for prevention and arrest of root caries on elderly participants using quantitative light-induced fluorescence (QLF). 23 participants with two or three non-cavitated root carious lesions were included and assigned to three groups of different varnishes (CF: Cervitec F, P: placebo, DP: Duraphate). Agents were applied once to root surface at baseline and in follow-up after 3, 6 and 9 months. The lesions were assessed clinically and with QLF. QLF-images were analyzed regarding fluorescence loss (ΔF), lesion volume (ΔQ) and bacterial activity (ΔR) before (t0), after 14 days (t1), 6- (t2) and 12-months (t3). CF showed a significant difference between t0 and t3: ∆F (- 12.51 [15.41] vs. - 7.80 [16.72], p = 0.012), ∆Q (- 2339.97 (20,898.30) vs. - 751.82 (5725.35), p < 0.001), ∆R (23.80 [41.70] vs. 7.07 [37.50], p = 0.006). Independently of the varnish application, preventive care seems positively influence the root caries progress. Although within CF group the strongest effect was observed, no superiority of a specific varnish application was confirmed over a 12-months QLF observation period. Extra topical fluoride can help remineralise dentin lesions and QLF can be used as a measurement method to determine changes in the dentin lesions.

Reversal of Root Caries with Casein Phosphopeptide-Amorphous Calcium Phosphate and Fluoride Varnish in Xerostomia.

Different formulas of topical fluoride have been used to manage root carious lesions. This clinical trial aimed to investigate the efficacy of a dental varnish containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and fluoride compared with fluoride alone in reversing/arresting root caries in xerostomic patients over 1 year. A total of 80 patients (age range 45-92 years) with primary root caries (n = 184 root carious lesions) and unstimulated salivary flow rate of <0.2 mL/min were randomly allocated to receive either dental varnish containing CPP-ACP and 5% fluoride (group 1: MI varnish; GC, Japan) (n = 41, 83 lesions), or dental varnish with 5% fluoride alone (group 2: NUPRO White; Dentsply, USA) (n = 39, 101 lesions). Clinical assessments with Severity Index (SI) for root caries, DIAGNOdent measurements, and varnish application were carried out at baseline, 3, 6, and 12 months. Standard oral hygiene instructions with 1,450 ppm fluoride toothpastes were provided for both groups. After 3 months, 63.9% (n = 46) of root caries in group 1 became hard (SI: 0) compared with 39.3% (n = 35) in group 2 (p < 0.01). After 6 and 12 months, the differences in SI were insignificant (group 1, n = 60, 83.3%) (group 2, n = 66, 74.2%) (p = 0.36), and (group 1, n = 60, 89.6%) (group 2, n = 67, 81.7%, n = 1 soft, 1.2%) (p = 0.29), respectively. In both groups, noncavitated leathery lesions were more likely to become hard when compared to the cavitated root caries. A significant decrease in plaque index, surface roughness, lesion dimension, and DIAGNOdent readings with a significant increase in lesion distance from the gingival margin was reported in both groups (p < 0.05). This study has provided evidence that fluoride dental varnish either with or without calcium and phosphate has the potential to arrest/reverse root caries, especially noncavitated lesions for patients with xerostomia.

Studies on antimicrobial peptide-loaded nanomaterial for root caries restorations to inhibit periodontitis related pathogens in periodontitis care.

AIMS: To prepare a novel antimicrobial peptide Nal-P-113 loaded poly (ethylene glycol) combined chitosan nanoparticles (Nal-P-113-PEG-CSNPs) for root caries restorations to control the periodontitis related pathogens in periodontitis care. METHODS: Nanoparticles were prepared by simple polymerisation method and characterised using effective analytical methods (TEM, UV, etc.). The antimicrobial activity and biofilm formation of Nal-P-113-PEG-CSNPs was tested against periodontal bacterial pathogens by different in vitro methods. RESULTS: The size of Nal-P-113 loaded PEG-Chitosn nanoparticles was 216.2 ± 1.6 nm. The drug encapsulation efficiency (%EE (w/w) of Nal-P-113-PEG-CSNPs was found to be 89.33 ± 1.67% (w/w). The antimicrobial examination showed that prepared NPs have effectively inhibited the growth of Fusobacterium nucleatum, Streptococcus gordonii, and Porphyromonas gingivalis with the MIC of 23 µg/mL, 6 µg/mL and 31 µg/mL, respectively. CONCLUSIONS: The prepared antimicrobial peptide-loaded PEG-CSNPs provide excellent in vitro efficiency but, further studies are necessary to confirm its therapeutic efficacy on periodontitis care.

Anti-Caries Effect of Arginine-Containing Formulations in vivo: A Systematic Review and Meta-Analysis.

OBJECTIVE: To assess the anti-caries effect of arginine-containing formulations in vivo on caries lesions compared with fluorides or placebo. METHODS: Randomized or quasi-randomized human clinical trials wherein arginine was delivered by any method were considered. The MEDLINE, Web of Science, EMBASE, Cochrane Library, and CBM databases were searched to identify relevant articles published up to December 2014. Grey literature was also searched. Two authors performed data extraction independently and in duplicate using data collection forms. Each included study was assessed using the Cochrane risk of bias assessment tool. RESULTS: Of the 470 studies screened, 31 full articles were scrutinized and assessed for eligibility. Ten studies (n = 15,546 participants) were selected for final inclusion. The meta-analysis results (n = 7 studies) demonstrated a synergistic effect of arginine when used in conjunction with fluoride on early coronal and root caries compared with placebo or fluoride alone. No specific side effects related to arginine usage were identified. CONCLUSIONS: When used in combination with a calcium compound and fluoride, arginine potentially provides a superior anti-caries effect compared with matched formulations of fluoride alone. However, the level of evidence was downgraded because of risks of bias and potential publication bias. In the future, more high quality, non-industry-supported clinical studies in this research area are required before any definitive recommendations can be made.

Topical agents for root caries prevention.

DATA SOURCES: PubMed, EMBASE and Cochrane Central Register of Controlled Trials. STUDY SELECTION: Randomised and nonrandomised, controlled, and prospective studies comparing preventive regimes for root caries were considered. Only English or German language studies were considered. DATA EXTRACTION AND SYNTHESIS: Standard data items were extracted. Mean differences (MD) and standard mean differences (SMD) were primary effect measures. Changes were calculated for DMFRS/DFRS (decayed, missing, filled root surfaces), and RCI (root caries index). Random-effects meta-analysis was conducted. Study quality was assessed using the Cochrane risk of bias tool and grading of evidence was performed according to the GRADE. RESULTS: Thirty trials reported in 34 studies involving 10,126 patients were included. Twenty-nine were RCTs, the other a controlled trial. Risk of bias was considered low for only five studies. In all 28 chemical agents were tested. Eleven studies assessed dentifrices; ten rinses; eight varnishes; three fluoride solutions; three gels; two ozone applications; one preventive dental regimen. Meta-analyses revealed that dentifrices containing 5,000 ppm F- (RR = 0.49; 95% CI= 0.42, 0.57; high level of evidence) or 1.5% arginine plus 1,450 ppm F- (RR = 0.79; 95% CI = 0.64, 0.98; very low level) are more effective in inactivating RCLs than dentifrices containing 1,100 to 1,450 ppm F-. Self-applied AmF/SnF2-containing dentifrice and rinse decreased the initiation of RCLs when compared with NaF products (SMD = 0.15; 95% CI = -0.22, 0.52; low level evidence). Mouth rinse containing 225 to 900 ppm F- revealed a significantly reduced DMFRS/DFRS (MD = -0.18; 95% CI = -0.35, -0.01; low level) when compared with a placebo rinse. Significantly reduced RCI was found for Chlorhexidine (MD = -0.67; 95% CI = -1.01, -0.32; very low level evidence) as well as SDF (MD = -0.33; 95% CI = -0.39, -0.28; very low level) when compared with placebo varnish. CONCLUSIONS: Based on meta-analysis, dentifrice containing 5,000 ppm F- and professionally applied CHX or SDF varnish may inactivate existing and/or reduce the initiation of RCLs. However, results should be interpreted with caution due to the low numbers of clinical trials for each agent, the high risk of bias within studies, and the limiting grade of evidence.

Effectiveness of fluorides in root caries prevention, Department of Veterans Affairs (2009-2018).

AIMS: The aim of this study was to examine the effectiveness of topical fluorides in prevention of root caries-related treatment in high caries risk Veterans. METHODS: This retrospective analysis of longitudinal data examined the effectiveness of professionally applied or prescription (Rx) fluoride treatment, in VHA clinics from FY 2009-2018. Professional fluoride treatments included 5% Sodium Fluoride (NaF) varnish (22 600 ppm fluoride), 2% NaF gel/rinse (9050 ppm fluoride), and 1.23% APF gel (12 300 ppm fluoride). The Rx for daily home use was 1.1% NaF paste/gel (5000 ppm fluoride). Outcomes studied were new root caries restorations or extractions and percent of patients with treatment over 1 year. Logistic regressions were adjusted for age, gender, race, ethnicity, chronic medical or psychiatric conditions, number of medication classes, anticholinergic drugs, smoking, baseline root caries treatment, preventive care, and time between first-last restoration in the index year. RESULTS: Root caries at baseline was associated with a high risk for new root caries. Veterans without root caries during the index year who received a fluoride gel/rinse intervention were 32-40% less likely to receive caries-related treatment for root caries during the follow-up period. Once Veterans had root caries, fluorides did not exhibit a positive effect. CONCLUSION: In older adults with high caries risk, early fluoride prevention is key, before root caries requires treatment.

Systematic review and network meta-analysis of restorative therapy and adhesive strategies in root caries lesions.

AIM: This systematic review and network meta-analysis (NMA) aimed to establish a clinically relevant hierarchy of the different adhesive and/or restorative approaches to restore cavitated root caries lesions through the synthesis of available evidence. MATERIALS AND METHODS: A systematic search was conducted in Medline/Web of Science/Embase/ Cochrane Library/Scopus/grey literature. RCTs investigating ≥2 restorative strategies (restorative /adhesive materials) for root caries lesions in adult patients were included. Risk of bias within studies was assessed (Cochrane_RoB-2) and the primary outcome was survival rate of restorations at different follow-up times (6-/12-/24-months). Network meta-analyses were conducted using a random effects model stratified by follow-up times. I2-statistics assessed the ratio of true to total variance in the observed effects. All available combinations of adhesives (1-SE: one-step self-etch; 2-3ER: two-/three-step etch-and-rinse) and restorative materials (conventional composite (CC) as well as conventional and resin-modified glass ionomer cements (GIC, RMGIC)) were included. Risk of bias across studies and confidence in NMA (CINeMA) were assessed. RESULTS: 547 studies were identified and nine were eligible for the NMA. In total, 1263 root caries lesions have been restored in 473 patients in the included clinical trials. Patients involved were either healthy (n = 6 trials), living in nursing homes (n = 1 trial) or received head-and-neck radiotherapy (n = 2 trials). There was statistically weak evidence to favour either of material/material combination regarding the survival rate. A tendency for higher survival rate (24-months) was observed for 2-3ER/CC (OR24mths 2.65; 95%CI=1.45/4.84) as well as RMGIC (OR24mths 2.05; 95%CI=1.17/3.61) compared to GIC. These findings were though not statistically significant and confidence of the NMA was low. CONCLUSION: An evidence-based choice of restorative strategy for managing cavitated root caries lesions is currently impossible. There is a clear need for more standardised, well-designed RCTs evaluating the retention rate of root caries restoration approaches.

The effect of silver nanoparticles in addition to sodium fluoride on remineralization of artificial root dentin caries.

BACKGROUND: Silver nanoparticle was developed to overcome the drawback of silver diamine fluoride. However, evidence is limited, especially in root caries. The aim of this study was to evaluate the remineralization effect of silver nanoparticles on root caries. MATERIALS AND METHODS: Fifty-five root human dentin slices size 5 × 5 mm2 from patients aged over 60 years old were immersed in demineralized solution to create artificial caries. Specimens were allocated into five groups according to the remineralizing agents: silver diamine fluoride (SDF), silver nanoparticles solution (AgNPs), silver nanoparticle solution followed by sodium fluoride varnish (AgNPs+NaF), sodium fluoride varnish (NaF), and tap water. After 8 days of pH-cycling challenge, the microhardness test, lesion depth evaluation, dentin surface morphology, and elemental analysis were performed. Data was analysed using F-test One-way ANOVA followed by Tukey's post hoc test and paired T-test. RESULTS: All test groups demonstrated a significantly higher microhardness value and lower lesion depth compared with the control group. AgNPs+NaF and NaF-treated groups showed lower efficacy than SDF. Crystal precipitation was presented in all groups composed of silver. CONCLUSION: Addition of fluoride varnish did not benefit for silver nanoparticles in preventing further demineralization. SDF provides the highest effectiveness in elderly root carious dentin.

Enhancement of mineral density and mechanical properties in root caries treated with silver diammine fluoride and glass ionomer cement, with emphasis on silver ion distribution.

OBJECTIVES: This study aimed to measure the distribution of silver ion (Ag+), mineral recovery, and nanohardness in carious lesions and comprehensively evaluate the degree of dentin restoration. METHODS: Sixty human teeth with root caries were randomly assigned to the control, silver diammine fluoride (SDF) [Safo], and SDF+Glass ionomer cement (GIC) treatment [Safo+Fuji] groups. Micro-computed tomography (micro-CT) was performed at five time points for each sample before/after treatment to evaluate mineral density within and around carious lesions. Three months following treatment, 12 samples were selected for synchrotron radiation X-ray fluorescence analysis to evaluate Ag+ distribution, while 15 samples were selected for nanoindentation. Data were analyzed using Dunnett's T3 test for micro-CT and Wilcoxon rank sum test with Bonferroni correction (p = 0.017) for nanoindentation. The correlation between hardness and mineral change was analyzed using the Spearman rank correlation coefficient. RESULTS: The Safo and Safo+Fuji groups showed significantly higher mineral recovery rates than did the control group (p < 0.001). In the Safo group, Ag+ accumulated in the deeper layers rather than the superficial layer of caries. In the Safo+Fuji group, Ag+ was found evenly distributed throughout caries, with only a few Ag+ detected in the GIC layer. Hardness in the Safo+Fuji group was significantly higher compared with the Safo group at depths in the range of 10-50 µm. CONCLUSION: In the presence of GICs, SDF exhibited high remineralization capacity when diffusing throughout carious lesions over time. Combined treatment with SDF and GIC could strengthen root dentin even in the presence of caries. CLINICAL SIGNIFICANCE: We found that combination treatment with SDF and GIC could increase mineral density in caries and improve the hardness of the tooth structure compared with fluoride-based agents alone. These findings might pave the way for future clinical trials to determine the therapeutic potential of nanotechnology-based restorative materials.

In situ detection of endogenous proteolytic activity and the effect of inhibitors on tooth root surface.

OBJECTIVES: The aim of this study was to clarify the distribution and activity of proteolytic enzymes and examine the inhibitory effects of various substances on this proteolytic activity on tooth root surfaces in situ. METHODS: Disk-shaped bovine tooth root samples were partly pretreated in acid solution (50 mM lactic acid buffer, pH 4.0) for 48 h. The fluorescence intensity of samples was detected with fluorescent substrate solution for collagenase and gelatinase using a stereoscopic fluorescence microscope for 60 min. The acid-pretreated and non-acid-pretreated root samples were treated with chlorhexidine (CHX), sodium fluoride (NaF), epigallocatechin gallate (EGCG), and calcium hydroxide (Ca(OH)2) for 10 min, and silver diamine fluoride (SDF) for 10, 30, and 60 s. These samples were immersed in the fluorescence substrate solution at pH 7.0, and the fluorescence intensity of samples was detected. The fluorescence intensity was calculated using analysis software. RESULTS: Gelatinase activity was detected in root samples. Gelatinase activity of the acid-pretreated side was significantly higher than that of the non-acid-pretreated side (1.63 times) at 60 min. CHX, EGCG, Ca(OH)2, and SDF decreased the gelatinase activity of root samples, while NaF had no effect. CONCLUSIONS: Gelatinase activity was detected from the root in situ and it was increased by acid-pretreatment. CHX, EGCG, Ca(OH)2, and SDF inhibited gelatinase activity. CLINICAL SIGNIFICANCE: Substances that inhibit proteolytic activity found in this research method will be useful for root caries prevention.

Older patients' perception of treating root caries with silver diamine fluoride - a qualitative study based on the Theoretical Domains Framework.

OBJECTIVES: Caries treatment with silver diamine fluoride (SDF) is effective, but often leads to irreversible tooth discoloration. This study aimed to investigate older patients' perceptions of root caries treatment with SDF and to identify factors that influence their decision process. METHODS: Fifteen interviews were conducted in older patients (mean, min/max: 83, 71/92 years) with root caries experience, following a semi-structured interview-guide based on the domains of the Theoretical Domains Framework (TDF) including three case vignettes of SDF treatment. Transcripts of the interviews were used to perform deductive and inductive content analysis along the TDF and Capability-Opportunity-Motivation-Behavior model (COM-B) to assess influential factors. RESULTS: All TDF domains and behavior determinants of the COM-B were covered, identifying twenty-two barriers, facilitators and conflicting themes. Main barriers for consenting to SDF treatment were patients' perceptions of permanent staining of visible root caries lesions, as well as preconceptions about those of others and lack of knowledge about root caries and SDF. Main facilitators were trust in advice given by dentists, especially regarding new treatment options, that aesthetics were less important in non-visible areas and the importance of tooth preservation and feasibility of treatments when immobile or in need of care. CONCLUSION: Permanent discoloration is an important barrier to older patients' acceptance of SDF treatment for visible root caries. However, patients appear to accept SDF treatment under certain conditions, including less visible lesions or in comparison to more invasive treatment options. CLINICAL SIGNIFICANCE: Our findings contribute to understanding both barriers and facilitators when treating root caries in older patients with SDF.

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.

Viability of bacteria associated with root caries after Nd:YAG laser application in combination with various antimicrobial agents: An in vitro study.

BACKGROUND: The neodymium-doped yttrium aluminum garnet (Nd:YAG) laser has various therapeutic applications in dentistry, including the treatment of dentin hypersensitivity and the bacterial reduction therapy in periodontology. The addition of antimicrobial agents may enhance the impact of the laser on bacterial viability. OBJECTIVES: This in vitro study aimed to assess the effect of Nd:YAG laser application in combination with various chemical antimicrobial agents, including hydrogen peroxide (H2O2), sodium hypochlorite (NaOCl), chlorhexidine (CHX), and sodium fluoride (NaF), on the viability of bacteria implicated in the etiology of root caries. MATERIAL AND METHODS: Three oral bacterial species were examined: Streptococcus mutans (S. mutans); Streptococcus sanguinis (S. sanguinis); and Enterococcus faecalis (E. faecalis). The bacteria were grown in broth at 37°C, and then treated with the chemical agents and/or irradiated with an Nd:YAG laser for 30 s. Each treatment modality was repeated 3 times: group 1 - no treatment; group 2 - 0.5% H2O2; group 3 - 0.5% NaOCl; group 4 - 0.12% CHX; group 5 - 2% NaF; group 6 - Nd:YAG laser irradiation; group 7 - laser and 0.5% H2O2; group 8 - laser and 0.5% NaOCl; group 9 - laser and 0.12% CHX; and group 10 - laser and 2% NaF. The viability of the bacteria was determined by plating them, counting viable colonies, converting the data into colony-forming units (CFUs)/mL, and transforming them into the log form. Statistical analysis was performed using the two-tailed paired t test. RESULTS: Irradiation with an Nd:YAG laser alone did not show a statistically significant effect against any of the bacterial species. The only effective antimicrobial used alone was CHX for S. mutans. Chlorhexidine with Nd:YAG resulted in a greater reduction in S. mutans and E. faecalis than either treatment alone. Meanwhile, H2O2 with Nd:YAG also showed an enhanced S. mutans reduction. Treatment with 0.5% NaOCl in conjunction with Nd:YAG brought the most significant reduction in viability for all bacteria in comparison with other treatment modalities. CONCLUSIONS: The Nd:YAG laser combined with 0.5% NaOCl resulted in the most substantial reduction in bacterial survival as compared to the antimicrobials or the Nd:YAG laser used alone.

Effect of silver nanoparticles associated with fluoride on the progression of root dentin caries in vitro.

OBJECTIVES: To assess the anti-proteolytic effect and potential to inhibit dentin root caries progression of a silver nanoparticle and fluoride solution (CNanoF) in comparison to silver diamine fluoride (SDF). METHODS: 48 specimens of root dentin artificial caries lesion were treated with 38% SDF, CNanoF, CNano or F (n = 6 per group). Ph cycling with demineralization and remineralization solutions simulated caries lesion progression. In addition, specimens were incubated with or without bacterial collagenase in the remineralization solution to induce dentin proteolytic degradation. Dentin degradation was assessed by weight loss rate and hydroxyproline (Hyp) release. Changes in cross-sectional microhardness, and lesion permeability and collagen integrity as determined by confocal laser scanning microscopy indicated potential for further demineralization inhibition. The effect of the solutions on the activity of metalloproteinases (MMP) -2 and -9 was also investigated. Statistical analysis consisted of ANOVA, Kruskal-Wallis, and linear mixed models with post-hoc pairwise Tukey, Dunn, and t-tests (α = 0.05). RESULTS: Treatment with SDF resulted in lower weight loss rate than did other solutions, but all groups showed similar Hyp release (p = 0.183). SDF resulted in greater microhardness at superficial layers of the caries lesions (p<0.05), while there were no differences among CNanoF, CNano, and F. Lesion permeability was similar among all groups after pH cycling (p>0.05), with or without the use of collagenase (p = 0.58). No statistically significant difference was noted among solutions regarding collagen integrity after pH cycling; however, SDF-treated dentin had a significant decrease in collagen integrity when collagenase was used (p = 0.003). Interestingly, only SDF was able to completely inactivate MMP-2 and -9. CONCLUSIONS: CNanoF and SDF both potentially prevent dentin degradation during caries lesion progression in vitro; however, SDF was more effective at inhibiting further tissue demineralization.

Clinical evaluation of demineralization and remineralization of intact root surface lesions in the clinic by a quantitative light-induced fluorescence system.

Detection of demineralization of root surface caries is an important issue since preventive approaches prolong tooth life. Quantitative light-induced fluorescence (QLF) has been shown to be useful for the laboratory assessment of demineralization of root surfaces. The aim of this study was to determine the demineralization and remineralization of root surface intact and cavitated caries lesions using a QLF system as a nondestructive in vivo method. Noncavitated and demineralized root surface lesions were detected and scored using the QLF system. Oral hygiene education was given and periodontal cleaning was completed before the remineralization treatment. After obtaining baseline QLF data, the patients were informed about the remineralization treatment. Fluoride varnish was applied to the carious lesions at the baseline visit, and the patients were then reviewed after 1, 2, 3 and 4 weeks, with QLF assessment and fluoride varnish application repeated at each review. Repeated-measures ANOVA (α = 0.05) showed significant differences between ΔQ values at each visit (p < 0.001); ΔQ showed marked decreases at all the cut-off values (15, 20, 25, 30). The changes in ΔQ were not affected by the cut-off value. The ΔQ values of QLF showed differences at all visits. The QLF system was able to detect early root surface caries lesions in vivo. Bifluoride 12 varnish improved mineral levels as shown by the QLF system. The treatment response to chemicals of intact noncavitated root surface carious lesions could be followed nondestructively in the clinic using QLF to quantify remineralization at recall visits. Teeth with root surface caries can be kept by controlling their remineralization.

Grape seed extract as a potential remineralizing agent: a comparative in vitro study.

OBJECTIVE: Remineralization is an effective treatment that may stop or reverse early tooth decay. Grape seed extract (GSE) is the potential remineralizing agent under investigation. MATERIALS AND METHODS: Sound human tooth sections were obtained from the cervical portion of the root and stored in demineralizing solution at 37°C for 96 hours to induce artificial root caries lesions. The sections were divided into four treatment groups including 6.5% grape seed extract, sodium monofluorophosphate (220 ppm) with 0.05% calcium glycerophosphate, 0.5% calcium glycerophosphate and control (no treatment). An in vitro pH cycling model was used to cycle the demineralized specimens through treatment solutions, acidic buffer and neutral buffer for 8 days at 6 cycles per day. Subsequently, they were evaluated using confocal laser scanning microscope. Data were analyzed using analysis of variance (p < 0.05). RESULTS: GSE revealed less demineralization and more remineralization compared with other groups. CONCLUSION: GSE promotes remineralization of artificial root caries lesions. CLINICAL SIGNIFICANCE: The search for the perfect remineralizing agent continues to this day. GSE could be a welcome addition to the remineralization armamentarium.

[Re-mineralization ability of Galla chinensis extracts on root carious lesions with or without non-collagen proteins].

OBJECTIVE: To evaluate the re-mineralization ability of Galla Chinensis extracts (GCE) on two artificial carious lesions in bovine root de-mineralized in vitro. METHODS: Fourteen bovine root blocks were divided into two parts from buccal to lingual direction. The mesial blocks were treated with a demineralization solution and the distant blocks were treated with another demineralization solution. Two specimens from each group were selected randomly and examined with polarization microscope (PLM). After all blocks were demineralized, half surface of the demineralized zone was covered and the another half was treated with 0.5% NaCl to extract soluble dentin phosphate protein (S-DPP). Then all specimens were submitted to pH-cycling for one week. In the first four days, all specimens were treated with GCE for 21 h and with demineralization solution for 3 h. In the remaining three days, all specimens were treated with GCE. The re-mineralization ability of GCE on the specimens was evaluated by laser scanning confocal microscope (LSCM). RESULTS: There existed intact surface layers on subsurface lesions but no surface layers were produced on erosive lesions. The re-mineralization ability of GCE on erosive lesions improved significantly with the treatment of 0.5% NaCl solution (P < 0.05). But it had no significant effect on subsurface lessions. CONCLUSION: Extraction of S-DPP with 0.5% NaCl can improve the re-mineralization ability of GCE on root caries with erosive lesions. This finding supports the proposition that Galla Chinesis may be a promising anti-caries natural medicine in the future.

Evaluation of quantitative light-induced fluorescence to assess lesion depth in cavitated and non-cavitated root caries lesions - An in vitro study.

BACKGROUND: This in vitro study aimed to assess carious lesions on root surfaces using quantitative light-induced fluorescence (QLF) and to compare the readings with axial lesion depth on µCT. METHODS: The root surfaces of 107 extracted human teeth were included after visual-tactile inspection. For further analysis, the following parameters were assessed: clinical findings (non-cavitated: leathery or hard, cavitated), QLF- (QLF-D Biluminator 2+), and µCT-images (Bruker Skyscan 1172). The shape of the undamaged tooth surface of the cavitated lesions was virtually re-constructed during µCT analysis. Clinical surface texture,% fluorescence loss, and lesion depth (µCT) were determined. STATISTICAL ANALYSIS: chi²-test, Spearman-Rho test, regression analysis. RESULTS: ∆F was significantly lower in non-cavitated leathery (-50.37 ± 15.10) and cavitated (-61.23 ± 9.92) compared to non-cavitated surfaces with a hard texture (-17.04 ± 16.10, p < 0.01). For non-cavitated surfaces, a negative correlation was observed between ∆F and lesion depth in µCT images regardless of texture (-0.748, p < 0.01). Regression analysis revealed that ∆F predicted lesion depth in µCT for non-cavitated surfaces (ß: 0.703, CI95: 0.67--0.43, p < 0.01). CONCLUSION: The percentage of fluorescence loss (∆F) in QLF predicted lesion depth of non-cavitated demineralized root surfaces. Therefore, QLF can be recommended for estimating the lesion depth of carious root lesions and seems to expand the possibilities of follow-up and lesion monitoring, especially for non-cavitated surfaces.