In vivo evaluation of laser fluorescence performance using different cut-off limits for occlusal caries detection

The aim of this in vivo study was to evaluate the performance of laser fluorescence (LF) comparing different cut-off limits for occlusal caries detection. One hundred and thirty first permanent molars were selected. Visual examination and LF assessments were performed independently. The extent of caries was assessed after operative intervention. New cut-off limits were established and compared with those proposed by the manufacturer and by Lussi et al. (Eur J Oral Sci 109:14-19, 2001). Similar sensitivity and higher specificity was found at D(2) (considering as disease only dentin caries) when the LF cut-off limits proposed by Lussi et al. and the new one were compared. At the D(3) threshold (considering as disease only deep dentin caries), no statistically significant difference among the cut-off limits for sensitivity was found. However, the new cut-off limits showed higher specificity. The LF device provided good ability to detect dentin caries lesions. Furthermore, the new cut-off limits and the values proposed by Lussi et al. could be suggested for the in vivo detection of occlusal caries.

In vivo bisphenol-a release from dental pit and fissure sealants: a systematic review

OBJECTIVE To search the literature and assess the short- and long-term release of bisphenol-A (BPA) in human tissues after treatment with dental sealants. DATA Two review authors performed data extraction independently and in duplicate using data collection forms. Disagreements were resolved by discussion with an arbiter. SOURCES Electronic database searches of published and unpublished literature were performed. The following electronic databases with no language and publication date restrictions were searched: MEDLINE (via Ovid and Pubmed), EMBASE (via ovid), Cochrane Trials Register and CENTRAL. The reference lists of all eligible studies were hand-searched. STUDY SELECTION In the absence of RCTs, six interventional and two observational studies, examining in vivo BPA release in human salivary, blood and urinary samples, were included. Due to the heterogeneity in methodology and reporting, the main synthesis of the results was qualitative. The quantitative synthesis based on the weighted Z-test could only include two studies. BPA levels identified in saliva ranged from traces below the method's detection limit to 30 μg/ml. In urine, BPA quantities spanned from 0.17 mg/g to 45.4 mg/g. BPA was not traced in any blood sample at any point of time in the relevant studies. The quantitative analysis showed evidence of BPA release one hour after sealant placement compared to the amount traced before restoration (Stouffer's z trend: <0.001). CONCLUSIONS The available evidence on this topic derived from studies that represent a moderate level of evidence. Nevertheless, the available evidence supports that BPA is released in saliva after sealant placement. CLINICAL SIGNIFICANCE From the qualititative and quantitative synthesis of studies, it is reasonable to conclude that BPA is released after placement of some dental pit and fissure sealants in the oral cavity. The biggest quantities are detected in saliva immediately after or one hour after their placement.

Traditional and novel methods for occlusal caries detection: performance on primary teeth

This study aimed to assess the performance of International Caries Detection and Assessment System (ICDAS), radiographic examination, and fluorescence-based methods for detecting occlusal caries in primary teeth. One occlusal site on each of 79 primary molars was assessed twice by two examiners using ICDAS, bitewing radiography (BW), DIAGNOdent 2095 (LF), DIAGNOdent 2190 (LFpen), and VistaProof fluorescence camera (FC). The teeth were histologically prepared and assessed for caries extent. Optimal cutoff limits were calculated for LF, LFpen, and FC. At the D (1) threshold (enamel and dentin lesions), ICDAS and FC presented higher sensitivity values (0.75 and 0.73, respectively), while BW showed higher specificity (1.00). At the D (2) threshold (inner enamel and dentin lesions), ICDAS presented higher sensitivity (0.83) and statistically significantly lower specificity (0.70). At the D(3) threshold (dentin lesions), LFpen and FC showed higher sensitivity (1.00 and 0.91, respectively), while higher specificity was presented by FC (0.95), ICDAS (0.94), BW (0.94), and LF (0.92). The area under the receiver operating characteristic (ROC) curve (Az) varied from 0.780 (BW) to 0.941 (LF). Spearman correlation coefficients with histology were 0.72 (ICDAS), 0.64 (BW), 0.71 (LF), 0.65 (LFpen), and 0.74 (FC). Inter- and intraexaminer intraclass correlation values varied from 0.772 to 0.963 and unweighted kappa values ranged from 0.462 to 0.750. In conclusion, ICDAS and FC exhibited better accuracy in detecting enamel and dentin caries lesions, whereas ICDAS, LF, LFpen, and FC were more appropriate for detecting dentin lesions on occlusal surfaces in primary teeth, with no statistically significant difference among them. All methods presented good to excellent reproducibility.

Performance of experienced dentists in Switzerland after an e-learning program on ICDAS occlusal caries detection

This study aimed to evaluate the effect of an e-learning program on the validity and reproducibility of the International Caries Detection and Assessment System (ICDAS) in detecting occlusal caries. For the study, 170 permanent molars were selected. Four dentists in Switzerland who had no previous contact with ICDAS examined the teeth before and after the e-learning program and scored the sites according to ICDAS. Teeth were histologically prepared and assessed for caries extension. The significance level was set at 0.05. Sensitivity before and after the e-learning program was 0.80 and 0.77 (D1), 0.72 and 0.63 (D2), and 0.74 and 0.67 (D3,4), respectively. Specificity was 0.64 and 0.69 (D1), 0.70 and 0.81 (D2), and 0.81 and 0.87 (D3,4). A McNemar test did not show any difference between the values of sensitivity, specificity, accuracy, and area under the ROC curve (AUC) before and after the e-learning program. The averages of wK values for interexaminer reproducibility were 0.61 (before) and 0.66 (after). Correlation with histology presented wK values of 0.62 (before) and 0.63 (after). A Wilcoxon test showed a statistically significant difference between before and after the e-learning program. In conclusion, even though ICDAS performed well in detecting occlusal caries, the e-learning program did not have any statistically significant effect on its performance by these experienced dentists.

Change of the condyle-position in maximum intercuspidation during digital, clinical occlusal analysis

Digital analysis of the occlusal contacts can be performed with the T-scan device (T Scan III, TekScan, Boston, USA). However, the thickness of the interocclusal T-scan sheet (100 μm) may lead to a displacement of the mandible. Thus, the aim of this study was to investigate the impact of the T-scan sheet on the position of the mandibular condyles in maximum intercuspidation. Twenty dentate subjects with healthy jaw function were enrolled in the study. An ultrasonic axiography device was used to measure the position of the condyles. Ten 3D condyle positions in maximum intercuspidation of the teeth were recorded: first the reference position without the sheet, then 3 times without the sheet, 3 times with the sheet, and finally again 3 times without the sheet. There was a statistically significant difference (Wilcoxon matched pairs test) between the condyle positions with and without the interocclusally positioned T-scan sheet (P < 0.0005). The T-scan device lead to a displacement of the condyles of about 1 mm mainly in ventral direction (P = 0.005). Thus, occlusal analysis is not performed in physiological, maximum intercuspidation. This has to be considered when interpreting the measured contact points.

Evaluation of different types of enamel conditioning before application of a fissure sealant

The aim of the study was to compare fissure sealant quality after mechanical conditioning of erbium-doped yttrium aluminium garnet (Er:YAG) laser or air abrasion prior to chemical conditioning of phosphoric acid etching or of a self-etch adhesive. Twenty-five permanent molars were initially divided into three groups: control group (n = 5), phosphoric acid etching; test group 1 (n = 10), air abrasion; and test group 2, (n = 10) Er:YAG laser. After mechanical conditioning, the test group teeth were sectioned buccolingually and the occlusal surface of one half tooth (equal to one sample) was acid etched, while a self-etch adhesive was applied on the other half. The fissure system of each sample was sealed, thermo-cycled and immersed in 5% methylene dye for 24 h. Each sample was sectioned buccolingually, and one slice was analysed microscopically. Using specialized software microleakage, unfilled margin, sealant failure and unfilled area proportions were calculated. A nonparametric ANOVA model was applied to compare the Er:YAG treatment with that of air abrasion and the self-etch adhesive with phosphoric acid (α = 0.05). Test groups were compared to the control group using Wilcoxon rank sum tests (α = 0.05). The control group displayed significantly lower microleakage but higher unfilled area proportions than the Er:YAG laser + self-etch adhesive group and displayed significantly higher unfilled margin and unfilled area proportions than the air-abrasion + self-etch adhesive group. There was no statistically significant difference in the quality of sealants applied in fissures treated with either Er:YAG laser or air abrasion prior to phosphoric acid etching, nor in the quality of sealants applied in fissures treated with either self-etch adhesive or phosphoric acid following Er:YAG or air-abrasion treatment.

Treatment of wastewaters from adhesives and sealants manufacture by ultrafiltration /

Mode of access: Internet.

A review of the use of chemical sealants for reduction of canal seepage losses, lower-cost canal lining program /

Mode of access: Internet.

Oral rehabilitation; complete occlusal reconstruction treatment of dental deformities and related subjects, the closed bite.

Mode of access: Internet.

In vitro effects of erosive challenge on the surface properties of sealants

Aim: To assess in vitro the surface roughness (Ra), Vickers hardness (VHN) and surface morphology of resin and glass ionomer materials used for sealants after dynamic erosive challenge. Methods: Twenty specimens of each material were prepared and divided into experimental (erosive challenge) and control groups (n=10): Protect Riva (SDI), Opallis Flow (3M ESPE), Fluroshield (Dentsply), Filtek Z350 XT Flow (3M ESPE). The erosive challenge was performed 4 times per day (90 s) in cola drink and for 2 h in artificial saliva for 7 days. The control specimens were maintained in artificial saliva. Ra and VHN readings were performed before and after erosion. The percentage of hardness loss (%VHN) was obtained after erosion. The surface morphology was evaluated by scanning electron microscopy (SEM). The data were analyzed by ANOVA, Tukey and paired t tests (α=0.05). Results: After erosion and saliva immersion, there was an increase in Ra values for all groups and Riva group showed the highest Ra values. After erosive challenge, Riva and Filtek groups showed significant decrease in VHN values, but Filtek group showed the greatest %VHN. For all groups there was inorganic particle protrusion and matrix degradation after erosion visualized by SEM images. Conclusions: Erosive challenge affected the surface properties of all materials used as sealants, particularly in the Riva and Filtek groups.

Effect Of Platform Connection And Abutment Material On Stress Distribution In Single Anterior Implant-supported Restorations: A Nonlinear 3-dimensional Finite Element Analysis.

Although various abutment connections and materials have recently been introduced, insufficient data exist regarding the effect of stress distribution on their mechanical performance. The purpose of this study was to investigate the effect of different abutment materials and platform connections on stress distribution in single anterior implant-supported restorations with the finite element method. Nine experimental groups were modeled from the combination of 3 platform connections (external hexagon, internal hexagon, and Morse tapered) and 3 abutment materials (titanium, zirconia, and hybrid) as follows: external hexagon-titanium, external hexagon-zirconia, external hexagon-hybrid, internal hexagon-titanium, internal hexagon-zirconia, internal hexagon-hybrid, Morse tapered-titanium, Morse tapered-zirconia, and Morse tapered-hybrid. Finite element models consisted of a 4×13-mm implant, anatomic abutment, and lithium disilicate central incisor crown cemented over the abutment. The 49 N occlusal loading was applied in 6 steps to simulate the incisal guidance. Equivalent von Mises stress (σvM) was used for both the qualitative and quantitative evaluation of the implant and abutment in all the groups and the maximum (σmax) and minimum (σmin) principal stresses for the numerical comparison of the zirconia parts. The highest abutment σvM occurred in the Morse-tapered groups and the lowest in the external hexagon-hybrid, internal hexagon-titanium, and internal hexagon-hybrid groups. The σmax and σmin values were lower in the hybrid groups than in the zirconia groups. The stress distribution concentrated in the abutment-implant interface in all the groups, regardless of the platform connection or abutment material. The platform connection influenced the stress on abutments more than the abutment material. The stress values for implants were similar among different platform connections, but greater stress concentrations were observed in internal connections.

The Influence Of Altered Occlusion On Pro-inflammatory Cytokine Levels In The Tmj Synovial Tissues Of Rats.

The aim of this study was to evaluate whether altered occlusion affects both the condylar cartilage thickness and the cytokine levels of the TMJs of rats. Thirty adult-male rats (n=30) were randomly assigned to three experimental conditions: a control group that underwent sham operations with unaltered occlusion; an FPDM group that underwent functional posterior displacement of the mandible that was induced by an incisor guiding appliance; and an iOVD group in which the increased occlusal vertical dimension was induced in the molars. The rats were subjected to the FPDM or iOVD model for 14 days and then killed. Both the right and left TMJs were removed and randomly assigned to examination with staining or immunoassay techniques. Toluidine blue staining was used to measure the thicknesses of the four layers of the articular cartilage (i.e., the fibrous, proliferating, mature, and hypertrophic layers). ELISA assays were used to assess the concentrations of the pro-inflammatory cytokines IL-1α, IL-1β, IL-6, and tumour necrosis factor (TNF-α). The measurements of the articular cartilage layers and cytokine concentrations were analyzed with ANOVA and Tukey's tests and Kruskal-Wallis and Dunn tests, respectively (α=5%). The thickness of articular cartilage in the FPDM group (0.3±0.03mm) was significantly greater than those of the control (0.2±0.01mm) and iOVD (0.25±0.03mm) groups. No significant difference was observed between the control and iOVD groups. The four articular cartilage layers were thicker in the FPDM group than in the control and iOVD groups, and the latter two groups did not differ one from each other. Both the FPDM and iOVD groups exhibited higher cytokine levels than did the control (p<0.05) group. Compared to the FPDM group, the iOVD group exhibited significantly higher levels of IL-1β and TNF-α. Both models induced inflammation in the TMJ and caused significant structural changes in the TMJ and surrounding tissues.

Discovery Of A Rare Pterosaur Bone Bed In A Cretaceous Desert With Insights On Ontogeny And Behavior Of Flying Reptiles.

A pterosaur bone bed with at least 47 individuals (wing spans: 0.65-2.35 m) of a new species is reported from southern Brazil from an interdunal lake deposit of a Cretaceous desert, shedding new light on several biological aspects of those flying reptiles. The material represents a new pterosaur, Caiuajara dobruskii gen. et sp. nov., that is the southermost occurrence of the edentulous clade Tapejaridae (Tapejarinae, Pterodactyloidea) recovered so far. Caiuajara dobruskii differs from all other members of this clade in several cranial features, including the presence of a ventral sagittal bony expansion projected inside the nasoantorbital fenestra, which is formed by the premaxillae; and features of the lower jaw, like a marked rounded depression in the occlusal concavity of the dentary. Ontogenetic variation of Caiuajara dobruskii is mainly reflected in the size and inclination of the premaxillary crest, changing from small and inclined (∼ 115°) in juveniles to large and steep (∼ 90°) in adults. No particular ontogenetic features are observed in postcranial elements. The available information suggests that this species was gregarious, living in colonies, and most likely precocial, being able to fly at a very young age, which might have been a general trend for at least derived pterosaurs.

Direct Adhesive Pin-retained Restorations For Severely Worn Dentition Treatment: A 1.5-year Follow-up Report.

Excessive occlusal surface wear can result in occlusal disharmony, functional and esthetic impairment. As a therapeutic approach, conventional single crowns have been proposed, but this kind of treatment is complex, highly invasive and expensive. This case report describes the clinical outcomes of an alternative minimally invasive treatment based on direct adhesive-pin retained restorations. A 64-year-old woman with severely worn dentition, eating problems related to missing teeth and generalized tooth hypersensitivity was referred for treatment. Proper treatment planning based on the diagnostic wax-up simulation was used to guide the reconstruction of maxillary anterior teeth with direct composite resin over self-threading dentin pins. As the mandibular remaining teeth were extremely worn, a tooth-supported overdenture was installed. A stabilization splint was also used to protect the restorations. This treatment was a less expensive alternative to full-mouth rehabilitation with positive esthetic and functional outcomes after 1.5 years of follow-up.