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.

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.

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.

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.

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.

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.

Performance of a light fluorescence device for the detection of microbial plaque and gingival inflammation.

OBJECTIVES: The hypothesis to be tested was that using the SOPROCARE system in fluorescence perio-mode allows scoring of microbial plaque that is comparable to the Turesky modification of the Quigley Hein plaque index (T-QH) and scoring of gingival inflammation comparable to the Silness and Löe gingival inflammation index (GI). MATERIALS AND METHODS: Fifty-five subjects with various amounts of microbial plaque were recruited. The T-QH and GI index were recorded. SOPROCARE pictures were recorded in fluorescence perio-mode and in daylight mode. Finally, conventional digital photographs were taken. All pictures were assessed using the same criteria as described for the clinical indices. RESULTS: The average T-QH was 1.1 ± 1.2 (mean ± SD). Scoring with SOPROCARE perio-mode led to a slightly higher average than the T-QH scores. SOPROCARE daylight mode and digital photography showed the highest plaque scores. The average GI index was 0.7 ± 0.9. SOPROCARE in perio-mode scored slightly lower. Linear regression fits between the different clinical indices and SOPROCARE scores were significantly different from zero demonstrating high goodness of fit. CONCLUSIONS: The study demonstrated that the SOPROCARE fluorescence assessment tool in perio-mode allows reliable judgment of microbial plaque and gingival inflammation levels similar to the established Turesky-modified Quigley Hein index and the Silness and Löe gingival inflammation index. Training on plaque-free teeth will actually reduce scoring errors. CLINICAL RELEVANCE: The SOPROCARE fluorescence tool in perio-mode provides reliable evaluation of microbial plaque and gingival inflammation for the dental clinician.

Laser all-ceramic crown removal-a laboratory proof-of-principle study-phase 1 material characteristics.

BACKGROUND AND OBJECTIVES: The removal of all-ceramic crowns is a time consuming and destructive procedure in the dental office. The removal of all-ceramic crowns using Er:YAG lasers has not been previously described in the scientific literature. The objective of this laboratory proof-of-principle study was to evaluate whether with regards to absorption and transmission characteristics of bonding cements and ceramics all-ceramic crowns can be removed from natural teeth using an Erbium laser. STUDY DESIGN/MATERIALS AND METHODS: The Fourier Transform Infrared Spectroscopy (FTIR) was used on flat ceramic samples (IPS Empress Esthetic (EE), E.max CAD, and E.max ZirCAD) to assess which infrared laser wavelengths transmit through the ceramics. Additionally, FTIR spectra for four bonding cements (Variolink Veneer, Variolink II, Multilink Automix, and SpeedCEM) were obtained. The Er:YAG laser energy transmission (wavelength 2,940 nm, 10 Hz repetition rate, pulse duration 100 µs at 126 mJ/pulse to 300 µs at 508 mJ/pulse) through different ceramic thicknesses was measured. Ablation thresholds for bonding cements were determined. Cement samples were directly irradiated or laser light was transmitted through ceramic samples. RESULTS: While the ceramics did not show any characteristic water absorption bands in the FTIR, all bonding cements showed a broad H2 O/OH absorption band. Some cements exhibited a distinct absorption peak at the Er:YAG laser emission wavelength. Depending on the ceramic thickness, EE and E.max CAD ceramics transmitted between 21 and 60% of the incident Er:YAG energy, with E.max CAD transmitting more energy than EE at comparable thicknesses. In contrast, E.max ZirCAD transmitted only 5-10% of the incident energy. Initial signs of cement deterioration occurred at 1.3-2.6 J/cm(2) . Multilink Automix, SpeedCEM, and Variolink II started ablation at 4.4-4.7 J/cm(2) . Variolink Veneer needed 44% less energy for ablation. CONCLUSION: Er:YAG laser energy can be transmitted through all-ceramic materials and those transmitted energies are sufficient for ablation of bonding cements.

Laser all-ceramic crown removal-a laboratory proof-of-principle study-phase 2 crown debonding time.

BACKGROUND AND OBJECTIVES: The removal of all-ceramic crowns is a time consuming procedure in the dental office. Little research has been done in alternative removal techniques for all-ceramic crowns. The objective of the second phase of this proof-of-principle laboratory pilot study was to evaluate whether Ivoclar Vivadent all-ceramic crowns can be efficiently removed from natural teeth without damage to the underlying tooth structure using an Erbium laser. STUDY DESIGN/MATERIALS AND METHODS: The ceramic materials used were IPS E.max CAD Lithium-disilicate (LS2 ) (E.max CAD) and IPS E.max ZirCAD Zirconium-oxide (ZrO2 ) (ZirCAD) (Ivoclar, Vivadent, Liechtenstein). Molars, either as stand-alone teeth or placed in an artificial row of teeth, were prepared to receive all-ceramic crowns. Copings and full contour crowns with either featheredge or regular margins were produced. The all-ceramic crowns were bonded to the teeth with Ivoclar Multilink Automix. The time for Er:YAG laser debonding of each crown was then measured. The Er:YAG (LiteTouch, Syneron, Yokneam, Israel) was used with an 1,100 µm diameter fiber tip with energies up to 600 mJ per pulse (wavelength 2,940 nm, 10 Hz repetition rate, pulse duration 100 µs at 126 mJ/pulse, and 400 µs at 590 mJ/pulse). The irradiation was applied at a distance of 10 mm from the crown surface following a defined pattern. Air-water spray was applied to the crowns at a rate of 67 ml/minute. RESULTS: All of the all-ceramic crowns were successfully debonded with the laser. On average, an all-ceramic E.max CAD crown was debonded in 190 ± 92 seconds (average ± SD). The debonding time for ZirCAD featheredge crowns was 226 ± 105 seconds and for ZirCAD crowns with regular margins it was 312 ± 102 seconds. No crowns fractured and no damage to the underlying dentin was detected. The bonding cement deteriorated due to the Er:YAG irradiation. Additionally, no carbonization at the dentin/cement interface was observed. CONCLUSION: Er:YAG laser energy can successfully be used to efficiently debond all-ceramic full contour crowns from natural teeth without damage to the underlying tooth structure. Lasers Surg. Med. 46:636-643, 2014. © 2014 Wiley Periodicals, Inc.

In-vivo occlusal caries prevention by pulsed CO2 -laser and fluoride varnish treatment--a clinical pilot study.

BACKGROUND AND OBJECTIVES: High caries prevalence in occlusal pits and fissures warrants novel prevention methods. An 86% reduction in dental enamel smooth surface demineralization in-vivo following short-pulsed 9.6 µm-CO(2) -laser irradiation was recently reported. The objective of this study was to conduct a blinded 12-month-pilot clinical trial of occlusal pit and fissure caries inhibition using the same CO(2) -laser irradiation conditions. STUDY DESIGN/MATERIALS AND METHODS: Twenty subjects, average age 14 years, were recruited. At baseline, second molars were randomized into test and control groups, assessed by International Caries Detection & Assessment System (ICDAS-II), SOPROLIFE light-induced fluorescence evaluator in daylight and blue-fluorescence mode and DIAGNOdent. An independent investigator irradiated test molars with a CO(2) -laser, wavelength 9.6 µm, pulse-duration 20 µs, pulse-repetition-rate 20 Hz, beam diameter 800 µm, average fluence 4.5 ± 0.5 J/cm(2), 20 laser pulses per spot. At 3-, 6- and 12-month recall teeth were assessed by ICDAS, SOPROLIFE and DIAGNOdent. All subjects received fluoride varnish applications at baseline and 6-month recall. RESULTS: All subjects completed the 3-month, 19 the 6-month and 16 the 12-month recall. At all recalls average ICDAS scores had decreased for the test and increased for the control fissures (laser vs. control, 3-month: -0.10 ± 0.14, 0.30 ± 0.18, P > 0.05; 6-month: -0.26 ± 0.13, 0.47 ± 0.16, P = 0.001; 12-month: -0.31 ± 0.15, 0.75 ± 0.17, P < 0.0001; mean ± SE, unpaired t-test) being statistically significantly different at 6- and 12-month recalls. SOPROLIFE daylight evaluation revealed at 6- and 12-months statistically significant differences in changes between baseline and recall for test and control molars, respectively (laser vs. control, 6-month: 0.22 ± 0.13, 0.17 ± 0.09, P = 0.02; 12-month: 0.28 ± 0.19, 0.25 ± 0.17, P = 0.03). For SOPROLIFE blue-fluorescence evaluation mean changes in comparison to baseline for the control and the laser treated teeth were also statistically significant for the 6- and 12-month recall. CONCLUSION: Specific microsecond short-pulsed 9.6 µm CO(2) -laser irradiation markedly inhibits caries progression in pits and fissures in comparison to fluoride varnish alone over 12 months.

Caries detection using light-based diagnostic tools.

Modern caries treatment concepts like caries management by risk assessment--CAMBRA--entail diagnosing early caries lesions in a precavitated stage to make it possible to reverse the caries process with remineralization and bacteria reduction efforts. Newer, sensitive caries diagnostic tools can serve not only for early detection but also for monitoring of caries lesions to confirm the success of prevention and remineralization efforts. This article describes light-based caries diagnostic tools, with emphasis on fluorescence-based techniques, and compares the most common available fluorescence-based tools with a standardized visual caries inspection system-the International Caries Detection and Assessment System (ICDAS II). Fluorescence tools that provide high-resolution fluorescence pictures are likely to provide more reliable scores than fluorescence devices that assess via a single spot. The better visibility of the high-resolution fluorescence imaging could prevent unnecessary operative interventions.

Performance of laser fluorescence devices and visual examination for the detection of occlusal caries in permanent molars.

The aim of this study was to evaluate the diagnostic capabilities of a laser fluorescence tool DIAGNOdent (KaVo, Biberach, Germany) and two light-emitting diode fluorescence tools-Spectra Caries Detection Aid (AIR TECHNIQUES, Melville, NY), and SOPROLIFE light-induced fluorescence evaluator in daylight and blue florescence mode (SOPRO, ACTEON Group, La Ciotat, France)-in comparison to the caries detection and assessment system (ICDAS-II) in detection of caries lesions. In 100 subjects (age 23.4±10.6 years), 433 posterior permanent unrestored teeth were examined. On the occlusal surfaces, up to 1066 data points for each assessment method were available for statistical evaluation, including 1034 ICDAS scores (intra-examiner kappa=0.884). For the SOPROLIFE tool, a new caries-scoring system was developed. Per assessment tool each average score for one given ICDAS code was significantly different from the one for another ICDAS code. Normalized data linear regression revealed that both SOPROLIFE assessment tools allowed for best caries score discrimination followed by DIAGNOdent and Spectra Caries Detection Aid. The area under the receiver operating characteristics curve calculations showed the same grading sequence when cutoff point ICDAS codes 0-1-2 were grouped together. Sensitivity and specificity values at the same cutoff were calculated (DIAGNOdent 87/66, Spectra Caries Detection Aid 93/37, SOPROLIFE 93/63, SOPROLIFE blue fluorescence 95/55.).

Er:YAG laser debonding of porcelain veneers.

BACKGROUND AND OBJECTIVES: The removal of porcelain veneers using Er:YAG lasers has not been previously described in the scientific literature. This study was designed to systematically investigate the efficacy of an Er:YAG laser on veneer debonding, possibly without damage to the underlying tooth, and preservation of the veneer integrity. STUDY DESIGN/MATERIALS AND METHODS: The Fourier Transform Infrared Spectroscopy was used on 10 flat veneer samples (IPS Empress Esthetic, e.max Press HT) to assess which infrared laser wavelengths transmits through a veneer. Additionally, Fourier Transform Infrared (FTIR) spectra for a bonding cement (RelyX) were obtained. Consequently, Er:YAG laser energy transmission (wavelength 2,940 nm, 10 Hz repetition rate, pulse duration 100 µseconds at 133 mJ/pulse) through different veneer thicknesses was measured. Twenty-four veneers were bonded to freshly extracted and prepared incisors. The energy necessary for debonding was determined and then the veneers were debonded with the laser. Time needed for total debonding was measured and possible damage to the underlying tooth structure was assessed by light microscopy. RESULTS: While the veneer materials did not show any characteristic water absorption bands in the FTIR, the bonding cement showed a broad H(2) O/OH absorption band. The veneers transmitted between 11.5% and 43.7% of the incident Er:YAG energy with Emax transmitting twice the energy as EE at comparable thicknesses. Initial signs of cement ablation occurred at 1.8-4.0 J/cm(2) with the fiber tip positioned at a distance of 3-6 mm from the veneer surface and 133 mJ output energy. All 24 bonded veneers were completely removed with an average removal time of 113 ± 76 seconds. Underlying tooth structure was not damaged. The debonding mainly occurred at the cement/veneer interface. None of the Emax veneers fractured during debonding, while 36% of the EE did. CONCLUSION: Er:YAG laser irradiation effectively debonds porcelain veneers while preserving tooth structure. Maintaining veneer integrity possibly depends on the flexure strength of the veneer porcelain.

Caries inhibition in vital teeth using 9.6-µm CO2-laser irradiation.

The aim of this study was to test the hypothesis that in a short-term clinical pilot trial short-pulsed 9.6 µm CO(2)-laser irradiation significantly inhibits demineralization in vivo. Twenty-four subjects scheduled for extraction of bicuspids for orthodontic reasons (age 14.9 ± 2.2 years) were recruited. Orthodontic brackets were placed on bicuspids (Transbond XT, 3M). An area next to the bracket was irradiated with a CO(2)-laser (Pulse System Inc, Los Alamos, New Mexico), wavelength 9.6 µm, pulse duration 20 µs, pulse repetition rate 20 Hz, beam diameter 1100 µm, average fluence 4.1 ± 0.3J∕cm(2), 20 laser pulses per spot. An adjacent nonirradiated area served as control. Bicuspids were extracted after four and twelve weeks, respectively, for a quantitative assessment of demineralization by cross-sectional microhardness testing. For the 4-week arm the mean relative mineral loss ΔZ (vol% × µm) for the laser treated enamel was 402 ± 85 (mean ± SE), while the control showed significantly higher mineral loss (ΔZ 738 ± 131; P = 0.04, t-test). The difference was even larger after twelve weeks (laser arm ΔZ 135 ± 98; control 1067 ± 254; P = 0.002). The laser treatment produced 46% demineralization inhibition for the 4-week and a marked 87% inhibition for the 12-week arm. This study shows, for the first time in vivo, that the short-pulsed 9.6 µm CO(2)-laser irradiation successfully inhibits demineralization of tooth enamel in humans.