In situ Effect of CO2 Laser (9.3 µm) Irradiation Combined with AmF/NaF/SnCl2 Solution in Prevention and Control of Erosive Tooth Wear in Human Enamel.

OBJECTIVES: This single-blind, controlled crossover in situ study aimed to evaluate the effect of CO2 laser (9.3 µm) irradiation combined with AmF/NaF/SnCl2 solution on prevention and control of erosive tooth wear (ETW) in human enamel. MATERIALS AND METHODS: Two trial conditions were analyzed, condition 1 as ETW prevention (sound tooth surface) and condition 2 as ETW control (in vitro initial erosive lesion). The experiment was conducted in 2 phases, one with and one without exposure to AmF/NaF/SnCl2 solution. Hundred and ninety-two samples of human enamel (3 × 3 × 1 mm) were randomly divided into 4 experimental groups for each condition: C, without treatment (negative control); F, AmF/NaF/SnCl2 solution (positive control); L, CO2 laser irradiation; and L + F, CO2 laser + AmF/NaF/SnCl2 solution. Twelve volunteers used a removable device, each containing 8 samples per phase. Ex vivo erosive challenges (4 × 5 min/day) and rinsing protocol (1 × 30 s/day) were performed. The surface loss was determined using optical profilometer (n = 12 per group), and the surface morphology was observed with scanning electron microscopy (n = 3). RESULTS: In condition 1, data were analyzed by one-way ANOVA and condition 2 by two-way repeated-measures ANOVA, both with Tukey post hoc tests (α = 5%). In condition 1, groups L (4.59 ± 2.95 µm) and L + F (1.58 ± 1.24 µm) showed significantly less surface loss in preventing ETW than groups C and F. In condition 2, in controlling the progression of ETW, L + F was the only group with no significant surface loss between initial erosive lesion (3.65 ± 0.16 µm) and after erosive challenge (4.99 ± 1.17 µm). CONCLUSIONS: CO2 9.3-µm laser application prevented and controlled ETW progression in human enamel, with greater efficiency when combined with AmF/NaF/SnCl2 solution application.

Demineralization prevention with a new antibacterial restorative composite containing QASi nanoparticles: an in situ study.

OBJECTIVES: To investigate whether a newly developed dental composite with quaternary ammonium silica dioxide (QASi) nanoparticles incorporated with other fillers into the restorative material demonstrates antibacterial activity by reducing enamel demineralization in an in situ gap model. MATERIALS AND METHODS: Twenty subjects wearing a lower removable partial denture (RPD) with acrylic flanges on both sides of the mouth were recruited into the 4-week in situ study. The gap model consisted of an enamel slab placed next to a composite, separated by a 38-µm space. In the split-mouth design on one side of the RPD, the composite was the Nobio Infinix composite (Nobio Ltd., Kadima, Israel), and the contralateral side used a control composite. Each participant received enamel slabs from one tooth. The gap model was recessed into the RPD buccal flange, allowing microbial plaque to accumulate within the gap. After 4 weeks of continuous wearing, decalcification (∆Z mineral loss) of the enamel slabs adjacent to the gap was determined by cross-sectional microhardness testing in the laboratory. RESULTS: The ∆Z for the antibacterial composite test side was 235±354 (mean±standard deviation [SD]; data reported from 17 participants) and statistically significantly lower compared to ∆Z of the control side (774±556; mean±SD) (paired t-test, P<0.0001; mean of test minus control -539 (SD=392), 95% confidence interval of difference: -741, -338). CONCLUSIONS: This in situ clinical study showed that composites with QASi antibacterial particles significantly reduced demineralization in enamel adjacent to a 38-µm gap over a 4-week period in comparison to a conventional composite. CLINICAL RELEVANCE: Composites with QASi nanoparticle technology have the potential to reduce the occurrence of secondary caries. TRIAL REGISTRATION: ClinicalTrials.gov #NCT04059250.

A Comparison of Four Caries Risk Assessment Methods.

Introduction: Caries risk assessment (CRA) is essential as the basis for successful management of dental caries. Of the many published CRA tools, four well-known ones are CAMBRA, Cariogram, American Dental Association (ADA), and American Academy of Pediatric Dentistry (AAPD) CRAs. The predictive accuracy of CAMBRA and Cariogram CRA tools have been examined in clinical outcomes studies in thousands of patients and the tools are widely used all over the world. The purpose of the present paper is three-fold, namely (1) to briefly review, compare and contrast these four CRA methods, (2) to provide a concise method for CRA introducing a quantitative component to the CAMBRA forms (CAMBRA 123), and (3) to guide the choice of CRA methods that will support caries management decisions. Comparison of Caries Risk Assessment Methods: In the present evaluation, the above-mentioned four CRA methods for ages 0-6 years and 6 years-adult were compared using 26 hypothetical patients (13 per age group). Comparison results show that Cariogram and CAMBRA categorized patients into identical risk categories. Each of the ADA and AAPD tools gave different results than CAMBRA and Cariogram in several comparison examples. CAMBRA 123 gave the same caries risk level results as the Cariogram and the CAMBRA methods for all hypothetical patients for both age groups. Conclusions: Both the Cariogram and the CAMBRA CRA methods are equally useful for identifying the future risk of dental caries. CAMBRA 123 shows promise as an easy-to-use quantitative method for CRA in clinical practice. The health care providers will be the ones to decide which CRA method will allow them to establish individualized, successful caries management therapies and how to combine these for the best care of their patients.

Evidence-Based Caries Management for All Ages-Practical Guidelines.

Introduction: The purpose of the present paper is to provide step-by-step guidelines for dental healthcare providers to manage dental caries based upon caries risk assessment (CRA) for ages 0-6 years and 6 years through adult. The manuscript reviews and updates the CAMBRA (caries management by risk assessment) system which includes CRA and caries management recommendations that are guided by the assessed risk level. Caries Risk Assessment: CAMBRA CRA tools (CRAs) have been evaluated in several clinical outcomes studies and clinical trials. Updated CAMBRA CRAs for ages 0-6 years and 6 years through adult are provided. These CRAs have been refined by the addition of a quantitative method that will aid the health care provider in determining the caries risk of individuals. Caries Management Based Upon Risk Assessment: Guidelines for individualized patient care are provided based upon the caries risk status, results of clinical exams and responses of the patient to questions in the CRA. These guidelines are based upon successful outcomes documented in several clinical outcomes studies and clinical trials. The paper includes a review of successful caries management procedures for children and adults as previously published, with additional emphasis on correct use of silver diamine fluoride (SDF) for children. The caries management plan for each individual is based upon reducing the caries risk factors and enhancing the protective factors with the additional aid of behavior modification. Beneficially altering the caries balance is coupled with minimal intervention restorative dentistry, if appropriate. These methods are appropriate for the management of dental caries in all patients.

Fissure caries inhibition with a CO2 9.3-µm short-pulsed laser-a randomized, single-blind, split-mouth controlled, 1-year clinical trial.

OBJECTIVES: The objective of this randomized, single-blind, split-mouth controlled, clinical trial was to evaluate whether the use of a short-pulsed 9.3-µm CO2 laser increases the caries resistance of occlusal pit and fissures in addition to fluoride therapy over 12 months. MATERIALS AND METHODS: A total of 60 participants, average age 13.1 years, were enrolled. At baseline, second molars were randomized into test and control, and assessed by ICDAS, SOPROLIFE, and DIAGNOdent. An independent investigator irradiated test molars with a CO2 laser (wavelength 9.3 µm, pulse duration 4 µs, pulse repetition rate 43 Hz, beam diameter 250 µm, average fluence 3.9 J/cm2, 20 laser pulses per spot). Test molars received laser and fluoride treatment, control teeth fluoride alone. Fluoride varnish was applied at baseline and at 6 months. After 6 and 12 months, teeth were again assessed. RESULTS: A total of 57 participants completed the 6-month and 51 the 12-month recall. Laser-treated surfaces showed very slight ICDAS improvements over time with ICDAS change - 1 in 11% and 8%, no changes (ICDAS change 0) in 68% and 67%, and slightly worsened (ICDAS change 1) in 19% and 24% at 6- and 12-month recalls, respectively, and worsened by two scores in 2% at both recall time points. Control teeth showed significantly higher ICDAS increases, with 47% and 25% showing ICDAS change 0, ICDAS change 1 in 49% and 55%, and ICDAS change 2 in 4% and 20% at 6- and 12-month recalls, respectively. Differences in ICDAS changes between the groups were statistically significant (P = 0.0002 and P < 0.0001; Wilcoxon's signed-rank test, exact). A total of 22% of the participants developed ICDAS 3 scores on the control teeth. CONCLUSIONS: Microsecond short-pulsed 9.3-µm CO2 laser irradiation markedly inhibits caries progression in pits and fissures in comparison with fluoride varnish alone. CLINICAL RELEVANCE: The 9.3-µm CO2 laser irradiation of pits and fissures enhances caries resistance. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02357979.

Demineralization Inhibition by High-Speed Scanning of 9.3 µm CO2 Single Laser Pulses Over Enamel.

BACKGROUND AND OBJECTIVE: In vitro studies were conducted to evaluate the use of an automated system for high-speed scanning of single 9.3 µm CO2 laser pulses in the inhibition of caries-like lesion formation in the enamel of extracted human molars. The effect of the laser in generating an acid-resistant layer and the effect of the layer on inhibiting surface mineral loss during pH cycling was explored. STUDY DESIGN/MATERIALS AND METHODS: Laser irradiation was performed with fluences of 0.6, 0.8, and 1.0 J/cm2 for single pulses of 1 mm diameter (1/e2 ), with pulse durations of 17, 22, and 27 microseconds, respectively. The laser was scanned at a 750 Hz pulse repetition rate in an automated pattern covering an area of 7 mm2 in 0.3 sec. Six treatment groups were investigated: three groups for each fluence for laser-only and three for laser irradiation with additional fluoride from a toothpaste slurry (sodium fluoride at 1100 ppm). Each group used non-irradiated areas, which included untreated controls for the laser-only groups and a fluoride-only treatment for the groups with additional fluoride. pH cycling was performed on both groups, followed by microhardness testing to determine the relative mineral loss (∆Z) from a caries-like formation and surface mineral loss (∆S). RESULTS: Laser irradiation with the 9.3 µm CO2 laser generated an acid-resistant layer of about 15 µm in depth. For the laser-irradiated samples with additional fluoride application, the relative mineral loss (∆Z) was 113 ± 63 vol%-µm, while for those with only fluoride application ∆Z was 572 ± 172 vol%-µm. At the highest fluence (1.0 J/cm2 ) used, an 80.2% inhibition of caries-like lesion was measured by ∆Z. Using only laser irradiation at the highest fluence resulted in an inhibition of caries-like lesion of 79.5% for the irradiated samples (∆Z = 374 ± 149 vol%-µm) relative to the control (∆Z = 1826 ± 325 vol%-µm). Surface microhardness tests resulted in an inhibition of surface softening, as measured by the Knoop Hardness Value (KHN) (108 ± 33 KHN for laser irradiated with additional fluoride, for non-irradiated controls with fluoride only 52 ± 16 KHN). Inhibition of surface loss was observed for all laser fluences, but the maximum surface loss for the untreated control group was only 2.2 ± 0.49 µm. CONCLUSIONS: The results demonstrate a significant benefit of the 9.3 µm CO2 laser at fluences of 0.6, 0.8, and 1.0 J/cm2 in caries-like lesion inhibition as measured by the relative mineral loss in depth and surface mineral loss, without significant damage to the enamel. Additionally, inhibition of surface softening and surface loss during pH cycling was observed. The surface loss was small compared with the overall lesion depth and thickness of the generated acid-resistant layer. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

In vitro CO2 9.3-µm short-pulsed laser caries prevention-effects of a newly developed laser irradiation pattern.

Caries prevention with different lasers has been investigated in laboratory studies and clinical pilot trials. Objective of this in vitro study was to assess whether 9.3-µm microsecond short-pulsed CO2 laser irradiation enhances enamel caries resistance without melting, with and without additional fluoride application. Seven groups of enamel, totaling 105 human enamel samples, were irradiated with 2 different carbon dioxide lasers with 2 different energy application systems (original versus spread beam; 9.3 µm wavelength, pulse repetition rate 43 Hz vs 100 Hz, fluence ranges from 1.4 to 3.9 J/cm2, pulse duration 3 µs to 18 µs). The laboratory pH-cycling was performed with or without additional fluoride, followed by cross-sectional microhardness testing. To assess caries inhibition, the mean relative mineral loss delta Z (∆Z) was determined. To evaluate for melting, scanning electron microscopy (SEM) examinations were performed. For the non-laser control groups with additional fluoride use, the relative mineral loss (ΔZ, vol% × µm) ranged between 512 ± 292 and 809 ± 297 (mean ± SD). ΔZ for the laser-irradiated samples with fluoride use ranged between 186 ± 214 and 374 ± 191, averaging a 58% ± 6% mineral loss reduction (ANOVA, P < 0.01 to P < 0.0001). For the non-laser-treated controls without additional fluoride, the mineral loss increased (ΔZ 914 ± 422 to 1224 ± 736). In contrast, the ΔZ for the laser-treated groups without additional fluoride ranged between 463 ± 190 and 594 ± 272 (P < 0.01 to P < 0.001) indicative of 50% ± 2% average reduction in mineral loss. Enhanced caries resistance was achieved by all applied fluences. Using the spread beam resulted in enhanced resistance without enamel melting as seen by SEM. CO2 9.3-µm short-pulsed laser irradiation with both laser beam configurations resulted in highly significant reduction in enamel mineral loss. Modifying the beam to a more homogenous profile will allow enamel caries resistance even without apparent enamel melting.

Efficacy of an adenosine triphosphate meter for evaluating caries risk in clinical dental practice.

BACKGROUND: Adenosine triphosphate bioluminescence (ATP-B) readings have been proposed as markers of caries risk. ATP readings may indicate bacteria or oral streptococci activity in microbial plaque. The authors of this study aimed to evaluate whether readings using a commercial ATP meter (CariScreen Testing Meter, Oral BioTech) are significantly different for patients with low, moderate, and high caries risk in the Caries Management by Risk Assessment Practice-Based Research Network study. METHODS: Twenty practice-based research network dentists enrolled 460 patients; 271 returned for 2 or more semiannual follow-up visits over 2 years. Dentists were trained and calibrated to perform ATP-B testing and caries risk assessment (CRA) using established protocols. ATP-B readings were compared via CRA category (low, moderate, high). Generalized estimating equations were used to compare the risk of experiencing incident clinical outcomes (newly recorded decayed, missing, or restored tooth surfaces and CRA disease indicators) according to ATP-B reading at prior patient visits (≥ 1,500 versus < 1,500 relative light units). RESULTS: Median ATP-B readings did not differ statistically significantly by clinician-assessed caries risk level (low, 2,323; moderate, 2,940; high, 3,217; P = .65). Adjusted for patient demographics and trial intervention assignment, higher readings were not associated with newly developed decayed, missing, or restored tooth surface (relative risk, 1.57; 95% confidence interval, 0.55 to 4.45) or disease indicators (relative risk, 1.08; 95% confidence interval, 0.85 to 1.37) at the following visit, whereas clinician-assessed caries risk level was strongly associated. CONCLUSIONS: ATP-B readings poorly predicted caries risk and future clinical outcomes. CRA incorporating multiple risk, protective, and disease indicators has superior predictive performance. PRACTICAL IMPLICATIONS: The findings of this study do not provide evidence supporting the use of ATP-B to predict caries risk.

Caries Management by Risk Assessment: Results from a Practice-Based Research Network Study.

Thirty dentists with clinical practices outside of a university setting were trained and calibrated successfully in DMFS and ICDAS-scoring. This randomized, controlled, parallel-arm, double-blind 2-year clinical trial with individual-level caries risk assignment of 460 patients to standard of care as control versus active CAMBRA treatment as intervention demonstrated that caries risk level, as well as caries disease indicators, were significantly reduced in the CAMBRA intervention group compared to the controls at all recall time points.

Change of salivary fluoride level with intake of fluoride releasing lozenges: A pilot study.

AIM: Long-term, low-level fluoride concentrations in saliva are highly effective in caries prevention and remineralization. The aim of the present two-phased study was to test whether fluoride-releasing lozenges compared to placebo significantly raise salivary fluoride levels above baseline achieved by 1100 ppm fluoride toothpaste in a double-blind, crossover pilot study. METHODS: In phase 1, a four-arm crossover basic study, four participants used one dissolvable lozenge with .25, 0.5, 1 or 1.5 mg fluoride for 1 hour. In phase 2, the three-arm crossover main study, 11 participants used three lozenges per day for 1 hour for 1 week, establishing long-term salivary fluoride levels dissolving 0 (control), 0.5 and 1.5 mg fluoride lozenges. Saliva was collected at baseline; during lozenge use; 5, 15, 30, and 60 minutes later; and early the next morning. Salivary fluoride levels were determined by laboratory diffusion analysis. RESULTS: In phase 1, 5 minutes after using one lozenge, salivary fluoride levels were above baseline (0.03 ppm), reaching 0.13 ± 0.19 ppm for the 0.25 mg and 0.73 ± 0.75 ppm for the 1.5 mg fluoride lozenge, dropping to baseline after 60 minutes. In phase 2, after 1 week use of 0.5 and 1.5 mg lozenges, respectively, for the 0.5 mg lozenge for 15 minutes and the 1.5 mg lozenge 30 minutes after use, the salivary levels were significantly higher than baseline/control (0.02 ppm). During 1-hour lozenge use, fluoride levels >0.1 ppm were consistently achieved. CONCLUSIONS: Fluoride lozenges achieved elevated salivary fluoride levels during use, but only for short periods after use.

Integrating Caries Management by Risk Assessment (CAMBRA) and Prevention Strategies Into the Contemporary Dental Practice.

In the past, the dental profession has adhered to a rigid tenet: remove decay from a tooth and then restore, a mindset that has been proverbially dubbed as "drill and fill." Today, dental caries is recognized as an infectious disease that affects children and adults throughout life. The philosophy of CAries Management By Risk Assessment, or CAMBRA®, represents a paradigm shift. The CAMBRA concept provides the dentist with scientific, evidence-based solutions with which to approach treatment of dental caries disease. This article reviews the current understanding of the caries balance, the process of demineralization and remineralization of tooth structure, caries risk assessment, and the different levels of caries risk. Adequate treatment protocols specifically related to the remineralization of non-cavitated lesions and CAMBRA validation studies are discussed.

MI Varnish and MI Paste Plus in a caries prevention and remineralization study: a randomized controlled trial.

OBJECTIVES: White spot lesions (WSLs) are a complication of orthodontic therapy. This study investigated the effect of MI (minimally invasive) Paste Plus (MIPP) and MI Varnish (MIV) on WSLs in orthodontic patients during a 12-month, randomized, single-blind, prospective, standard-of-care controlled clinical trial. MATERIALS AND METHODS: Forty subjects, recruited from the UCSF School of Dentistry Orthodontics Clinic, were randomly assigned to the experimental (twice-daily 1100 ppm fluoride toothpaste, daily MIPP, quarterly MIV application) or control group (twice-daily 1100 ppm fluoride toothpaste, fluoride rinse recommendation). Facial surfaces of incisors, canines, and first bicuspids were evaluated at baseline, 3, 6, and 12 months using the enamel decalcification index (EDI) and the international caries detection and assessment system (ICDAS). RESULTS: Findings from 37 subjects are reported. At 12 months, teeth receiving experimental treatment were at lower but not significantly different odds of increased EDI scores (odds ratio, OR 0.63; intra-patient cluster-adjusted 95% CI 0.43, 1.18) and not associated with increased ICDAS scores (OR 0.99; 95% CI 0.64, 1.54). There was no statistically significant difference in mean patient-level EDI sum (experimental group 40.2; control 41.3; t test p = 0.80), ICDAS score (experimental 22.3; control 22.6; Mann-Whitney U test p = 0.80), or percentage of scored surfaces with ICDAS > 0 (experimental 54.6%; control 55.2%; t test p = 0.88). Salivary fluoride levels were significantly higher at 12 months for the experimental than for the control group (0.20 ± 0.26 versus 0.04 ± 0.04 ppm, Mann-Whitney U test p < 0.01). CONCLUSIONS: Applying daily MIPP and quarterly MIV resulted in no statistically significant differences in EDI sum and ICDAS scores. Higher salivary fluoride levels in the experimental group suggest that MIPP and MIV effectively deliver fluoride when used clinically. CLINICAL RELEVANCE: Daily MIPP and quarterly MIV applications do not appear to reduce significantly WSLs incidence during fixed orthodontic treatment.

Calibration of dentists for Caries Management by Risk Assessment Research in a Practice Based Research Network - CAMBRA PBRN.

BACKGROUND: To prove that Caries Management by Risk Assessment (CAMBRA) can be successfully implemented in dental practices outside of the university setting, dentists in the San Francisco Bay Area (CA) were approached to participate in a Practice Based Research Network (PBRN) study. The overall goal of the CAMBRA-PBRN study was to recruit 30 dentists to perform a two-year study involving approximately 900 patients. Goal of the calibration study was to standardize and calibrate dentists potentially participating in the CAMBRA-PBRN study. METHODS: To minimize inter-examiner variability in data collection, including classification of carious lesions and recording of existing restorations, participating dentists were trained and calibrated in accurate DMFS (decayed, missing, filled surfaces) charting. Dentists were also trained and calibrated to diagnose and differentiate between sound surfaces and non-cavitated caries lesions (International Caries Detection and Assessment - ICDAS scores 1 and 2) for posterior occlusal surfaces. Thirty dentists were calibrated to a single gold standard examiner (BJ) during 6 calibration sessions, between 2011 and 2014. Kappa statistics were used to determine inter-examiner reliability on 13 or more patients, aged 12-63 (average age 38 ± 15 years), per examiner during each session, resulting in 94 patient encounters over the course of all 6 sessions. To participate in the main study, examiners needed to achieve a minimum required kappa of 0.75. During the calibration process, examiners scored between 1036 and 2220 tooth surfaces. RESULTS: The kappa values (unweighted kappa) of the participating dentists compared to the gold standard examiner ranged from 0.75 to 0.90, with an average kappa of 0.84 ± 0.03. 90% of the examiners achieved overall kappa values above 0.8. However, separate reliability for assessment of non-cavitated lesions, as in other studies, was lower (0.55 ± 0.15). Multiple subcategories were evaluated. All dentists reached sufficient reliability values to proceed into the study; nevertheless, one dentist discontinued with the study due to scheduling conflicts. CONCLUSIONS: The high inter-examiner reliability results have shown that dentists who work in primarily non-research based practices can be effectively standardized and calibrated in data collection, based on specific guidelines created to anticipate potential research study scenarios.

Bond strength of etch-and-rinse and self-etch adhesive systems to enamel and dentin irradiated with a novel CO2 9.3 µm short-pulsed laser for dental restorative procedures.

The objective of this study was to evaluate the influence of CO2 9.3 µm short-pulsed laser irradiation on the shear bond strength of composite resin to enamel and dentin. Two hundred enamel and 210 dentin samples were irradiated with a 9.3 µm carbon dioxide laser (Solea, Convergent Dental, Inc., Natick, MA) with energies which either enhanced caries resistance or were effective for ablation. OptiBond Solo Plus [OptiBondTE] (Kerr Corporation, Orange, CA) and Peak Universal Bond light-cured adhesive [PeakTE] (Ultradent Products, South Jordan, UT) were used. In addition, Scotchbond Universal [ScotchbondSE] (3M ESPE, St. Paul, MN) and Peak SE self-etching primer with Peak Universal Bond light-cured adhesive [PeakSE] (Ultradent Products) were tested. Clearfil APX (Kuraray, New York, NY) was bonded to the samples. After 24 h, a single plane shear bond test was performed. Using the caries preventive setting on enamel resulted in increased shear bond strength for all bonding agents except for self-etch PeakSE. The highest overall bond strength was seen with PeakTE (41.29 ± 6.04 MPa). Etch-and-rinse systems achieved higher bond strength values to ablated enamel than the self-etch systems did. PeakTE showed the highest shear bond strength with 35.22 ± 4.40 MPa. OptiBondTE reached 93.8% of its control value. The self-etch system PeakSE presented significantly lower bond strength. The shear bond strength to dentin ranged between 19.15 ± 3.49 MPa for OptiBondTE and 43.94 ± 6.47 MPa for PeakSE. Etch-and-rinse systems had consistently higher bond strength to CO2 9.3 µm laser-ablated enamel. Using the maximum recommended energy for dentin ablation, the self-etch system PeakSE reached the highest bond strength (43.9 ± 6.5 MPa).

The Effect of Calibration on Caries Risk Assessment Performance by Students and Clinical Faculty.

Caries management requires a complete oral examination and an accurate caries risk assessment (CRA). Performing Caries Management by Risk Assessment (CAMBRA) is inefficient when the caries risk level assignment is incorrect. The aim of this study was to evaluate the ability of faculty members and students at one U.S. dental school to correctly assign caries risk levels for 22 CRA cases, followed by calibration with guidelines on how to use the CRA form and a post-calibration test two months after calibration. Inter-examiner reliability to a gold standard (consensus of three experts) was assessed as poor, fair, moderate, good, and very good. Of the 162 students and 125 faculty members invited to participate, 13 students and 20 faculty members returned pre-calibration tests, for response rates of 8% and 16%, respectively. On the post-calibration test, eight students and 13 faculty members participated for response rates of 5% and 10%, respectively. Without guidelines and calibration, both faculty members and students when evaluated as one group performed only poor to fair in assigning correct caries risk levels. After calibration, levels improved to good and very good agreements with the gold standard. When faculty and students were evaluated separately, in the pre-calibration test they correctly assigned the caries risk level on average in only one-quarter of the cases (students 24.1%±13.3%; faculty 23.6%±17.5%). After calibration, both groups significantly improved their correct assignment rate. Faculty members (73.8% correct assignments) showed even significantly higher correct assignment rates than students (47.7% correct assignments). These findings suggest that calibration with a specific set of guidelines improved CRA outcomes for both the faculty members and students. Improved guidelines on how to use a CRA form should lead to improved caries risk assessment and proper treatment strategy for patients.

AmF/NaF/SnCl2 solution reduces in situ enamel erosion - profilometry and cross-sectional nanoindentation analysis.

This in situ study aimed to investigate the effect of a tin-containing fluoride solution in preventing enamel erosion. Also, its effects on the partly demineralized zone were assessed for the first time. Thirteen volunteers participated in this 2-phase study, wearing removable intra-oral appliances containing four sterilized bovine enamel slabs, for 8 days, where 2 treatment protocols were tested using samples in replicas (n = 13): CO - no treatment (negative control) and FL - AmF/NaF/SnCl2 solution (500 ppm F-, 800 ppm Sn2+, pH = 4.5). Samples were daily exposed to an erosive challenge (0.65% citric acid, pH 3.6, 4 min, 2x/day). In the 2nd phase, volunteers switched to the other treatment protocol. Samples were evaluated for surface loss using a profilometer (n = 13) and a cross-sectional nanohardness (CSNH) test (n = 13) was carried out in order to determine how deep the partly demineralized zone reaches below the erosive lesion. The data were statistically analyzed by two-way ANOVA. Erosive challenges lead to smaller enamel surface loss (p < 0.001) in the FL group when compared to group CO. Data from CSNH showed that there was no significant difference in demineralized enamel zone underneath erosion lesions between the groups. An amorphous layer could be observed on the surface of enamel treated with tin-containing solution alone. Under the experimental conditions of this in situ study, it can be concluded that AmF/NaF/SnCl2 solution prevents enamel surface loss but does not change the hardness of the partly demineralized zone near-surface enamel.

AmF/NaF/SnCl2 solution reduces in situ enamel erosion - profilometry and cross-sectional nanoindentation analysis

Abstract This in situ study aimed to investigate the effect of a tin-containing fluoride solution in preventing enamel erosion. Also, its effects on the partly demineralized zone were assessed for the first time. Thirteen volunteers participated in this 2-phase study, wearing removable intra-oral appliances containing four sterilized bovine enamel slabs, for 8 days, where 2 treatment protocols were tested using samples in replicas (n = 13): CO - no treatment (negative control) and FL - AmF/NaF/SnCl2 solution (500 ppm F-, 800 ppm Sn2+, pH = 4.5). Samples were daily exposed to an erosive challenge (0.65% citric acid, pH 3.6, 4 min, 2x/day). In the 2nd phase, volunteers switched to the other treatment protocol. Samples were evaluated for surface loss using a profilometer (n = 13) and a cross-sectional nanohardness (CSNH) test (n = 13) was carried out in order to determine how deep the partly demineralized zone reaches below the erosive lesion. The data were statistically analyzed by two-way ANOVA. Erosive challenges lead to smaller enamel surface loss (p < 0.001) in the FL group when compared to group CO. Data from CSNH showed that there was no significant difference in demineralized enamel zone underneath erosion lesions between the groups. An amorphous layer could be observed on the surface of enamel treated with tin-containing solution alone. Under the experimental conditions of this in situ study, it can be concluded that AmF/NaF/SnCl2 solution prevents enamel surface loss but does not change the hardness of the partly demineralized zone near-surface enamel.

The Effects of Faculty Calibration on Caries Risk Assessment and Quality Assurance.

Accurate caries risk assessment (CRA) plays a pivotal role in managing the disease of dental caries. The aim of this quality assurance study was to determine if faculty calibration training using a specific set of guidelines in a single session would improve the faculty members' CRA decision making. A calibration seminar was held in December 2014 at the Virginia Commonwealth University School of Dentistry, during which seven completed CRA forms for simulated patients were used to test 55 faculty members' risk assignment level before and after an instructional lecture was given. The results showed a statistically significant increase in the proportion of faculty members responding correctly for five of the seven cases on the pre- and posttests (p<0.01). One case showed no significant increase in correct responses (p=0.07), and on the seventh case, which presented low caries risk, there was a significant decrease in the percentage responding correctly (p<0.0001) due to an increase in the proportion overestimating caries risk. This study's findings were consistent with those in previous studies that, without calibration, faculty members are not necessarily accurate at CRA diagnosis. Since the calibration training improved these faculty members' caries risk assessment scoring, future studies should extend to evaluations for both faculty and students.

Caries inhibition with a CO2 9.3 µm laser: An in vitro study.

BACKGROUND AND OBJECTIVES: The caries preventive effects of different laser wavelengths have been studied in the laboratory as well as in pilot clinical trials. The objective of this in vitro study was to evaluate whether irradiation with a new 9.3 µm microsecond short-pulsed CO2 -laser could enhance enamel caries resistance with and without additional fluoride applications. STUDY DESIGN/MATERIALS AND METHODS: One hundred and one human tooth enamel samples were divided into seven groups. Each group was treated with different laser parameters (CO2 -laser, wavelength 9.3 µm, 43 Hz pulse-repetition rate, pulse duration between 3 µs at 1.5 mJ/pulse to 7 µs at 2.9 mJ/pulse). A laboratory pH-cycling model followed by cross-sectional microhardness testing determined the mean relative mineral loss delta Z (ΔZ) for each group to assess caries inhibition in tooth enamel by the CO2 9.3 µm short-pulsed laser irradiation. The pH-cycling was performed with or without additional fluoride. RESULTS: The non-laser control groups with additional fluoride had a relative mineral loss (ΔZ, vol% × µm) that ranged between 646 ± 215 and 773 ± 223 (mean ± SD). The laser irradiated and fluoride treated samples had a mean ΔZ ranging between 209 ± 133 and 403 ± 245 for an average 55% ± 9% reduction in mineral loss (ANOVA test, P < 0.0001). Increased mean mineral loss (ΔZ between 1166 ± 571 and 1339 ± 347) was found for the non-laser treated controls without additional fluoride. In contrast, the laser treated groups without additional fluoride showed a ΔZ between 470 ± 240 and 669 ± 209 (ANOVA test, P < 0.0001) representing an average 53% ± 11% reduction in mineral loss. Scanning electron microscopical assessment revealed that 3 µs pulses did not markedly change the enamel surface, while 7 µs pulses caused some enamel ablation. CONCLUSION: The CO2 9.3 µm short-pulsed laser energy renders enamel caries resistant with and without additional fluoride use. The observed enhanced acid resistance occurred with the laser irradiation parameters used without obvious melting of the enamel surface as well as after irradiation with energies causing cutting of the enamel. Lasers Surg. Med. 48:546-554, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Approximal and occlusal carious lesions: Restorative treatment decisions by California dentists.

BACKGROUND: Investigators use questionnaire surveys to evaluate treatment philosophies in dental practices. The aim of this study was to evaluate the management strategies California dentists use for approximal and occlusal carious lesions. METHODS: In May 2013, the authors e-mailed a questionnaire that addressed approximal and occlusal carious lesion management (detection and restorative threshold, preferred preparation type, and restorative materials) to 16,960 dentists in California. The authors performed a χ(2) statistical analysis to investigate the relationship between management strategies and respondent demographic characteristics. RESULTS: The authors received responses from 1,922 (11.3%) dentists; 42.6% of the respondents would restore approximal lesions at the dentinoenamel junction, and 33.4% would wait until the lesion reached the outer one-third of dentin. The preferred preparation type was the traditional Class II preparation. Dentists who graduated more recently (20 years or less) were more likely to delay approximal restorations (P < .0001); 49.9% of the more recent graduates would wait to restore an occlusal lesion until the outer one-third of dentin was involved, and 42.6% would restore a lesion confined to enamel. CONCLUSIONS: There is wide variety among California dentists regarding their restorative treatment decisions, with most dentists restoring a tooth earlier than the literature would advise. More recent dental graduates were more likely to place their restorative threshold at deeper lesions for approximal carious lesions. PRACTICAL IMPLICATIONS: Clinical evidence shows that noncavitated carious lesions can be remineralized; therefore, early restorative treatment may no longer be necessary or appropriate. Noninvasive and minimally invasive measures should be taken into consideration.