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.

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.

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.

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 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.

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.

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 evidence for professionally applied fluoride therapy to prevent and arrest dental caries in older adults: A systematic review

OBJECTIVE

To assess the clinical evidence for professionally applied fluoride therapy to prevent and arrest caries in older adults.

DATA/SOURCES

Two independent researchers searched the English literature published up to 31st Dec 2021 in five databases (PubMed, Scopus, the Cochrane Library, EMBASE, and Web of Science) for clinical trials with a comparison group on professionally applied fluoride therapy for caries prevention or arrest at older adults aged ≥60 years with any follow-up period. The outcomes were the mean difference in the number of new caries/caries-prevented fraction and caries arrest rate. The Cochrane guidelines were used for the risk of bias assessment.

STUDY SELECTION/RESULTS

Five hundred and twenty-seven studies were identified, and seven studies were finally included. Five studies were rated as having 'low risk'. The root caries-prevented fraction of 38% silver diamine fluoride (SDF) solution, 5% sodium fluoride (NaF) varnish, and 1.23% acidulated phosphate fluoride (APF) gel were 25-71%, 64%, and 32%, respectively. Meta-analysis indicated a decrease in the number of new root caries by 0.55 (95% CI: 0.32-0.78; p < 0.001) and an overall proportion of arrested root caries of 42% (95% CI: 33% to 49%; p < 0.001) after receiving 38% SDF application at the 24-month follow-up.

CONCLUSIONS

According to the findings, 5% NaF varnish and 1.23% APF gel prevented root caries, whereas 38% SDF solution prevented and arrested root caries in older adults. More well-designed clinical trials should be conducted to investigate various methods in caries prevention and arrest in older adults.

CLINICAL SIGNIFICANCE

Preventive measures effective in other age groups may not suit older adults, as caries type and associated risk factors vary. To date, no systematic review has evaluated professionally applied fluoride therapy in older adults. Evidence from clinical trials in older adults could aid clinical practice and public health measures. The International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42022307025.

Silver Diamine Fluoride (SDF) in the management of root caries in elders: a systematic review and meta-analysis

This systematic review was undertaken to address the PICO question: Is silver diamine fluoride (SDF) effective in preventing and arresting root caries lesions in (RCLs) elders? Systematic literature searches were conducted of electronic databases [PubMed, Embase, and CENTRAL (Cochrane Controlled Register of Trials)] and hand searches were performed to identify studies reporting on the use of SDF in elders to prevent and arrest root caries. Prospective clinical studies were included. Two independent investigators performed the literature search and data extraction. A total of 277 studies were identified; of those 3 randomized controlled clinical trials were included for data extraction and analysis. A meta-analysis, using a fixed-effects model, was performed on the mean active RCLs present after SDF intervention compared to controls at 24 months (3 studies), and 30-36 months (2 studies) post-intervention. The fixed-effects model revealed a significant decrease in the mean new active RCLs post intervention with SDF compared to controls at both 24 months (95%CI: 0.265 - 0.638; I2=0.0%; Overall: Z=4.749, p<0.001), and at 30-36 months (95%CI: 0.329 - 0.812; I2=0.0%; Overall: Z=4.629, p<0.001). A funnel plot ruled out any publication bias and the risk of bias was judged to be low. This systematic review and meta-analysis provides evidence that the application of silver diamine fluoride prevents and arrests root caries in elders.

Remineralising effects of fluoride varnishes containing calcium phosphate on artificial root caries lesions with adjunctive application of proanthocyanidin

OBJECTIVES

To evaluate the remineralising effects of fluoride (F) varnishes containing bioavailable calcium-phosphate compound (Ca-P) based remineralisation systems and 5000 ppm F toothpaste (FTP) on root caries lesions (RCLs) and the potential effects of proanthocyanidin (PA) for the treatments of RCLs when used as an adjunct to F regimens.

METHODS

Demineralised root dentine and a pH-cycling model were used to mimic RCLs and the oral environment. Remineralising effects of MI Varnish^TM (MIV) containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and Clinpro™ White Varnish (CPWV) containing tri-calcium phosphate (TCP) along with FTP and PA were evaluated regarding the birefringence, elemental composition, mechanical properties and mineral density of remineralised dentine with Duraphat^TM as a comparison.

RESULTS

MIV, CPWV and Duraphat^TM promoted the incorporation of F into RCLs and increased mineral density but did not change microhardness of root dentine significantly. Surface microhardness increased significantly when MIV or CPWV was used with 5000 ppm FTP. Application of PA with F regimens significantly increased subsurface mineral density. When PA was applied with MIV or CPWV along with FTP, the highest ion uptake and relative mineral gain (%ΔZ) was achieved, and significant increase of microhardness was up to 30 μm depth. Generally, MIV was associated with a higher mineral content gain than CPWV.

SIGNIFICANCE

Treatment of carious root surfaces remains challenging due to the complex pathological processes and difficulty in restoring the highly organised structure of root dentine. Treatment strategies targeting both remineralisation and preservation of the dentinal organic matrix have the potential to improve the fluoride-mediated remineralisation approaches.

Effects of silver diamine fluoride/potassium iodide on artificial root caries lesions with adjunctive application of proanthocyanidin

Treatment of carious root surfaces remains challenging due to the complex pathological processes and difficulty in restoring the original structure of root dentine. Current treatments targeting the de-/re-mineralisation processes are not entirely satisfactory in terms of the protection of the dentinal organic matrix and the highly organised structure of dentine. In this in vitro study, a cross-linking agent - proanthocyanidin (PA) was used in conjunction with a fluoride-based treatment - silver diamine fluoride/potassium iodide (SDF/KI) to putatively stabilise the organic dentinal framework as well as strengthen the collagen-mineral phase interaction. The effectiveness of this strategy was evaluated 24 h after application in terms of the distribution of ion uptake and microstructure of dentine after treatment as well as analysis of the nano-mechanical properties using a dynamic behaviour model. Results showed that individual use of SDF/KI significantly improved the surface microhardness and integrated mineral density (Z) up to 60 µm depth and the recovery of creep behaviour of demineralised dentine in the surface area compared to that treated with deionised distilled water (DDW). The combined treatment of PA and SDF/KI achieved a more homogenous mineral distribution throughout the lesions than SDF/KI alone; a more significant incremental increase in surface microhardness and Z was observed. Specifically, a superior effect on the subsurface area occurred with PA + SDF/KI, with significant improvements in microhardness, elastic modulus and recovery of creep behaviour of the demineralised dentine. Application of SDF/KI induced small discrete crystal formation distributed over the dentine surface and PA contributed to the formation of slit-shaped orifices of the dentinal tubules that were partially occluded. STATEMENT OF SIGNIFICANCE: Demographic transitions and improved oral health behaviour have resulted in increased tooth retention in elderly people. As a consequence, the risk of root dentine caries is increasing due to the age-associated gingival recession and the related frequent exposure of cervical root dentine. Root caries is difficult to repair because of the complex aetiology and dentine structure. The recovery of dentine quality depends not only on reincorporation of minerals but also an intact dentinal organic matrix and the organic-inorganic interfacial structure, which contribute to the biomechanics of dentine. With the capability of dentine modification, cross-linking agents were applied with a fluoride regimen, which improved its treatment efficacy of root caries regarding the distribution of ion uptake and recovery of dentine biomechanics.

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.

Grape products and oral health

Oral diseases, including dental caries, periodontal disease, and tooth loss, affect the majority of the population and can affect a person's overall health. Raisins contain polyphenols, flavonoids, and high levels of iron that may benefit human health. However, their oral health benefits are less well understood. We hypothesized that raisins contain antimicrobial phytochemicals capable of suppressing oral pathogens associated with caries or periodontal diseases and thus benefit oral health. Through antimicrobial assay-guided fractionation and purification, compounds identified with growth inhibition against oral pathogens were oleanolic acid, oleanolic aldehyde, linoleic acid, linolenic acid, betulin, betulinic acid, 5-(hydroxymethyl)-2-furfural, rutin, beta-sitosterol, and beta-sitosterol glucoside. Oleanolic acid suppressed in vitro adherence of cariogenic Streptococcus mutans biofilm. When the effect of raisins and raisin-containing bran cereal on in vivo plaque acidogenicity was examined in 7- to 11-y-old children, it was found that raisins did not reduce the plaque pH decline below pH 6 over the 30-min test period. Compared with commercial bran flakes or raisin bran cereal, a lower plaque pH drop was noted in children who consumed a raisin and bran flake mixture when no sugar was added (P < 0.05). Grape seed extract, high in proanthocyanidins, positively affected the in vitro demineralization and/or remineralization processes of artificial root caries lesions, suggesting its potential as a promising natural agent for noninvasive root caries therapy. Raisins represent a healthy alternative to the commonly consumed sugary snack foods.

Fluoride interventions for root caries: a review

PURPOSE

To review in a systematic approach the effectiveness of specific fluoride treatments on the root caries activity in adults.

MATERIALS AND METHODS

An electronic search of the National Library of Medicine, Washington DC (Medline-PubMed), and the specialist trials register of the Cochrane Oral Health Group up to and including April 2005 was performed using specific search terms to identify randomised controlled trials, controlled clinical trials and longitudinal studies of at least 3 months duration, which investigated the effect of specific fluoride treatments with regard to root caries activity and/or incidence in healthy adults. Comparisons were made against the root caries status before the initiation of the additional fluoride application regimen and between groups in controlled studies. The papers were screened independently by two reviewers (MH and SP).

RESULTS

Out of 348 titles and abstracts, six papers fulfilled the selection criteria and were processed for data extraction. The highest level of evidence was presented in the two papers using a double-blind controlled randomised clinical trial (Wallace et al, 1993; Baysan et al, 2001). Both these studies indicate that the increased application of fluoride in the form of a high concentration dentifrice or additional mouthwash had a positive effect on the root caries incidence/severity.

CONCLUSION

Additional fluoride appears to be a preventive and therapeutic treatment for root caries.

The Effect of Antibacterial Monomer MDPB on the Growth of Organisms Associated with Root Caries

MDPB, 12-methacryloyloxydodecylpyridinium bromide, was tested for its ability to inhibit the growth of organisms associated with active root caries lesions and to modify the growth characteristics of these organisms at sub-MICs. MICs and MBCs of MDPB for independent isolates (n=5) of the following taxa: Streptococcus mutans, Streptococcus oralis, Streptococcus salivarius, Actinomyces naeslundii, Actinomyces israelii, Actinomyces gerensceriae, Actinomyces odontolyticus, Lactobacillus spp., and Candida albicans were determined, and the effects at sub-MIC on microbial growth kinetics were assessed. All isolates were sensitive to inhibition by MDPB. The median MICs and MBCs of MDPB for these organisms were in the range of 3.13 to 25.0 microg/ml and 6.25 to 50.0 microg/ml, respectively. As for the influence of pH, inhibition was sensitive to acidic pH. Even at sub-MICs, the growth of all strains, measured as cell yield and doubling time, was significantly reduced. Based on the results of this study, MDPB exhibited the potential to inhibit the growth of microbiota associated with active root caries lesions.

Rehardening of caries-like lesions in root surfaces by saliva substitutes

OBJECTIVE

This study sought to evaluate whether root dentine caries-like lesions could be remineralised by saliva substitutes.

METHODS

Root dentine slabs (3 x 3 x 2 mm) were cut from bovine incisors, ground flat, polished and pre-tested for Knoop microhardness (KHN) at five locations spaced 500 microm apart and 500 microm from the left edge of each sectioned piece. After 60 out of the 100 slabs had been selected based upon their KHN values, specimens were coated with wax except for their outer surface. Specimens were then cycled through a highly cariogenic challenge model to induce caries-like lesions, whose formation was confirmed by KHN measurements located 500 microm from the right edge of the specimen. According to a randomised complete block design, the experimental units (n = 15) were exposed to 1.5 ml of saliva substitutes, based on either mucin (MC) or carboxymethylcellulose (CM), to natural human saliva (HS) or to 100% relative humidity (RH) over 20 days. Remineralisation was verified by KHN measurements located 1000 microm apart from the right edge of the specimen.

RESULTS

Analysis of variance indicated a significant (p < 0.0001) difference among the KHN values attained by the carious root dentine after exposure to the remineralising agents. Tukey's test ascertained that remineralisation was greatest with MC, intermediate with CM and least with HS, but rehardening did not reach the pre-caries lesion formation values.

CONCLUSION

Saliva substitutes may provide partial remineralisation to preformed caries-like lesions in root dentine.

The Use of Ozone in Dentistry and Medicine

There is growing interest in the use of ozone in oral healthcare and the National Institute for Clinical Excellence (NICE) is at present reviewing the evidence for its effectiveness in the management of occlusal and plain surface caries. These are only two of the clinical problems for which ozone can, and has, been used; it has also been employed for a wide variety of other purposes in both dentistry and medicine. This pale blue-coloured gas plays an important role as a natural constituent in the higher layer of the Earth's atmosphere. There is growing evidence that it can be employed as a useful therapeutic agent. This paper reviews its therapeutic uses to date and suggests its possible future clinical applications. Consumer demands for this strong oxidant may increase as the general public becomes increasingly aware of its therapeutic capacity and the non-invasive manner in which it can be administered.

Clinical reversal of root caries using ozone, double-blind, randomised, controlled 18-month trial

OBJECTIVE

To assess the effect of an ozone delivery system, combined with the daily use of a remineralising patient kit, on the clinical severity of non-cavitated leathery primary root carious lesions (PRCL's), in an older population group.

DESIGN

A total of 89 subjects, (age range 60-82, mean +/- SD, 70.8 +/- 6 years), each with two leathery PRCL's, were recruited. The two lesions in each subject were randomly assigned for treatment with ozone or air, in a double-blind design, in a general dental practice. Subjects were recalled at three, six, 12 and 18 months. Lesions were clinically recorded at each visit as soft, leathery or hard, scored with a validated root caries severity index.

RESULTS

There were no observed adverse events. After three months, in the ozone-treated group, 61 PRCL's (69%) had become hard and none had deteriorated, whilst in the control group, four PRCL's (4%) had become worse (p<0.01). At the six-month recall, in the ozone group, seven PRCL's (8%) remained leathery, the remaining 82 (92%) PRCL's had become hard, whilst in the control group, 10 PRCL's had become worse (11%) and one had become hard (p<0.01). At 12 and 18 months, 87 Subjects attended. In the ozone group at 12 months, two PRCL's remained leathery, compared to 85 (98%) that had hardened, whilst in the control group 21 (24%) of the PRCL's had progressed from leathery to soft, i.e. became worse, 65 PRCL's (75%) were still leathery, and one remained hard (p<0.01). At 18 months, 87 (100%) of ozone-treated PRCL's had arrested, whilst in the control group, 32 lesions (37%) of the PRCL's had worsened from leathery to soft (p<0.01), 54 (62%) PRCL's remained leathery and only one of the control PRCL's had reversed (p<0.01).

CONCLUSIONS

Leathery non-cavitated primary root caries can be arrested non-operatively with ozone and remineralising products. This treatment regime is an effective alternative to conventional "drilling and filling".

Effect of ozone on the oral microbiota and clinical severity of primary root caries

PURPOSE

To assess the effect of ozone on the microbial flora and clinical severity of primary root caries.

METHODS

26 patients with 70 primary root carious lesions (PRCLs) were entered. Each PRCL was classified in terms of color, cavitation, size, hardness, distance from the gingival margin and severity. Overlying plaque was then removed and each lesion dried. A biopsy was taken from half of each PRCL using a sterile excavator. Subsequently, the remaining lesions were exposed to ozone gas for a period of either 10 seconds (n = 35) or 20 seconds (n = 35) and a further biopsy was taken.

RESULTS

Using a paired Student t-test, a significant (P < 0.001) difference (mean +/- SE) in total micro-organisms was observed in the ozone-treated samples after either a 10 seconds (log10 4.35 +/- 0.49) or 20 seconds (log10 0.46 +/- 0.26) ozone application compared with the control samples (log10 7.00 +/- 0.24) and (log10 6.00 +/- 0.21) respectively. Using Pearson's correlation tests, there were significant correlations for the reduction in total micro-organisms after 10 seconds of ozone application with cavitation, size, distance from gingival margin and severity of PRCLs (P < 0.05). In conclusion, ozone application either for 10 or 20 seconds dramatically reduced most of the micro-organisms in PRCLs without any side effects recorded at recall intervals between 3 and 5.5 months. Out of the 65 PRCLs reviewed, 33 lesions had become hard, 27 lesions reversed to severity index 1 from severity index 2, and five lesions remained the same following ozone application for a period of either 10 or 20 seconds.

Remineralization of advanced root dentin lesions in vitro

The possibility for remineralization of advanced root dentin lesions was investigated in vitro. Lesions were produced in acidic buffer solution with 0.1 and 0.5 ppm fluoride, for 3 and 5 weeks, respectively, using a single-section model. Next, the sections were immersed in a remineralization solution containing 0.1 ppm F (as NaF) for 20 weeks. Microradiographs were made after each 4-week-period. The lesions were around 500 micro m deep, with mineral loss values between 11,000 and 18000 vol%.microm. After 20 weeks of remineralization, the absolute amounts of deposited mineral ranged from 7500 to 10000 vol%. micro m, corresponding to a repair between 50 and 85%. Lesion depth was, on average, reduced by 199 micro m. This was not significantly different (at p < 0.05) between the four experimental groups. This study showed that remineralization of advanced dentinal lesions is possible in spite of the virtual absence of mineral in the lesion body after demineralization. The surface layer of the lesion was the preferred site for mineral deposition until mineral content values reached those of sound dentine. The mineral content in the lesion body increased with time, at a rate reflecting the initial severity of the lesion. We conclude that a remineralized surface layer does not inhibit transport of mineral ions to the body and that the remineralization in the lesion body reflected the number of sites for crystal growth.

Penetration of an antibacterial dentine-bonding system into demineralized human root dentine in vitro

In this study, the penetration of three proprietary dentine-bonding agents (Prime & Bond 2.1, Single Bond, Liner Bond 2) and experimental dentine-bonding systems incorporating an antibacterial monomer, 12-methacryloyloxydodecylpyridinium bromide (MDPB), into artificial root caries lesions was evaluated, and the bactericidal activity of each material against Streptococcus mutans or Lactobacillus casei impregnated into demineralized dentine blocks was assessed. All of the commercial dentine-bonding agents were capable of penetrating into the artificial carious lesions to more than 150 microm. The depth of penetration of the experimental systems, which were based on Liner Bond 2, was not significantly different from that of their parent product. Liner Bond 2 primer exhibited the greatest bactericidal effects among the three proprietary dentine-bonding agents tested. Bactericidal activities of experimental primers containing MDPB were greater than those of any other products, and the application of 4% MDPB-containing primer resulted in complete killing of bacteria in demineralized dentine. The results indicate that the penetration of dentine-bonding agents into extensively demineralized root dentine is possible in vitro, and the experimental dentine-bonding systems containing the antibacterial monomer MDPB are capable of killing bacteria within demineralized dentine. This could be of benefit when managing root caries lesions.

Effect of a solution with high fluoride concentration on remineralization of shallow and deep root surface caries in vitro

A root dentin single-section model was developed to compare the efficacy of different fluoride treatments on the remineralization of lesions. Shallow ( approximately 170 microm) and deep ( approximately 400 microm) lesions were produced in acetic acid buffer solutions (pH 5.0) with 0.1- and 0.5-ppm fluoride for 3 days and 2 weeks, respectively. Next, the sections were pH-cycled for 4 weeks. Following the pH cycling, all sections were first remineralized for 5 weeks, then subjected to 10 days of demineralization. The treatments were (1) no treatment (control), (2) daily 1,450-ppm NaF toothpaste, (3) weekly 4,000-ppm fluoride solution, (4) a combination of treatments 2 and 3. In the shallow lesions, the 4,000-ppm fluoride solution and the combination treatment enhanced mineral deposition at the lesion front, producing a second, slightly hyperremineralized layer. Similarly, in the deep lesions a second remineralized layer was detected. In all lesions, the fluoride solution treatment showed significantly more remineralization compared to the control and the toothpaste treatment (p<0.05), most of which was formed during the pH cycling. In the demineralization period, the control showed significantly higher mineral loss than all other treatments. These results indicate that a 4,000-ppm fluoride solution might be effective for remineralization of root dentin lesions even over 400 microm depth.

Reversal of primary root caries using dentifrices containing 5,000 and 1,100 ppm fluoride

This study compared the ability of two sodium fluoride dentifrices, one containing 5,000 ppm fluoride (Prevident 5000 Plus) and the other 1,100 ppm fluoride (Winterfresh Gel), to reverse primary root caries lesions (PRCLs). A total of 201 subjects with at least one PRCL each entered the study and were randomly allocated to use one of the dentifrices. After 6 months, 186 subjects were included in statistical analyses. At baseline and after 3 and 6 months, the lesions were clinically assessed and their electrical resistance measured using an electrical caries monitor. After 3 months, 39 (38.2%) of the 102 subjects in the 5,000 ppm F- group and 9 (10.7%) of 84 subjects using the 1,100 ppm F- dentifrice, had one or more PRCLs which had hardened (p = 0.005). Between baseline and 3 months, the log10 mean +/- SD resistance values of lesions for subjects in the 1,100 ppm F- group had decreased by 0.06+/-0.55, whereas those in the 5,000 ppm F- group had increased by 0.40+/-0.64 (p<0.001). After 6 months, 58 (56.9%) of the subjects in the 5,000 ppm F- group and 24 (28.6%) in the 1,100 ppm F- group had one or more PRCLs that had become hard (p = 0.002). Between baseline and 6 months, the log10 mean +/- SD resistance values of lesions for subjects in the 1,100 ppm F- group decreased by 0.004+/-0.70, whereas in the 5,000 ppm F- group, they increased by 0.56+/-0.76 (p<0.001). After 3 and 6 months, the distance from the apical border of the root caries lesions to the gingival margin increased significantly in the 5,000 ppm F- group when compared with the 1,100 ppm F- group. The plaque index in the 5,000 ppm F- group was also significantly reduced when compared with the 1,100 ppm F- group. The colour of the lesions remained unchanged. It was concluded that the dentifrice containing 5,000 ppm F- was significantly better at remineralising PRCLs than the one containing 1,100 ppm F-.

Evaluation of Carisolv for the chemo-mechanical removal of primary root caries in vivo

The objective of this study was to evaluate a new chemo-mechanical method (Carisolv) for the removal of primary root caries in vivo in terms of efficiency, treatment time and patient perception. Thirty-eight patients participated in an open, randomised and controlled study. Of the 60 root carious lesions included, 34 were randomised for chemo-mechanical treatment and 26 for drilling. A within-subject comparison was used whenever the patient had two cavities, which was the case for 22 subjects. All the Carisolv-treated cavities became caries free, as did all but one of those treated with drilling, as judged by an independent examiner. Only 4 of 34 patients asked for anaesthesia in the Carisolv group compared with 6 of 26 patients in the drilling group. Of those who did not use anaesthesia, 12 individuals in the drilling group experienced some pain compared with none in the chemo-mechanical group (p<0.001). The mean treatment time for the Carisolv method was 5.9+/-2.2 min, compared with 4.5+/-2.0 min for drilling; time for anaesthesia excluded (p<0.05). No negative reactions or adverse effects were recorded during the study. All 55 teeth examined in the 1-year follow-up were found to be sensitive using an electric pulp tester, and there was no difference regarding the condition of fillings between the lesions treated with Carisolv and drilling. It can be concluded that root caries can be effectively removed using the Carisolv method. The longer treatment time was compensated by less need for anaesthesia.

Root caries: prevention and chemotherapy

PURPOSE

Root caries is a problem of importance among dentate elderly. Greater life expectancies at both birth and age 65, combined with improvements in tooth retention across all age groups, have resulted in an increasing number of Americans who have retained their teeth into old age. This increase in numbers of teeth combined with the increase in the percent of teeth with recession has in turn resulted in older persons with more root surfaces at risk for caries than ever before. The purpose of this article is to review the literature on the prevention and chemotherapeutic approach to root caries.

METHODS

A review of the literature and synthesis of this information resulted in recommendations for the improved root caries risk assessment and the development of clinical examination protocols and strategies for prevention and treatment.

RESULTS

Clinicians can better identify persons at risk for root caries in their practice. People who are older, have moderate to severe periodontal bone loss and gingival recession, are impaired, have poor oral hygiene, take multiple medications, have partials, have retained root tips and the recently unemployed or retired are all at increased risk for root caries. Examination strategies should include the use of at least annual bite-wing radiographs (vertical bite-wings in persons with significant attachment loss) and careful examination of the proximal tooth surfaces. Once identified as low, moderate or high risk, daily and professionally applied fluoride therapies should be combined with dietary modifications, and in high risk individuals, antimicrobial agents for both the remineralization of early lesions and prevention of further root caries.

De/remineralization from sodium fluoride dentifrices

PURPOSE

To test the demineralization/remineralization effects of sodium fluoride dentifrices using an in situ single-section crown model system.

MATERIALS AND METHODS

A fluoride dose response was evaluated using 0, 1100 and 2800 ppm F-, along with the effects of an enhanced fluoride delivery system (polyampholyte-NaF). The single-section crown model was employed with supervised toothbrushing twice a day. At the end of each 1-month study leg, sections were removed and replaced with new sections for the next leg. Both before and after the double-blind, crossover portion of the study, sections were evaluated by polarized light microscopy and microradiography. The change in mineral content of the enamel and root lesions was analyzed by ANOVA with a Waller-Duncan K-Ratio Test post hoc.

RESULTS

The placebo dentifrice group showed a loss of mineral and was statistically different from all groups. The fluoride dentifrices showed increasing amounts of enamel mineral gain, with increasing fluoride concentration. The polyampholyte-NaF delivery system with 1100 ppm F- was equivalent to the 2800 ppm F- dentifrice. Root lesions gave similar rank-order results although all treatments showed demineralization or mineral loss.