In Vitro Evaluation of the Accuracy of Three Electronic Apex Locators Using Different Sodium Hypochlorite Concentrations.

Background and Objectives: The aim of this study was to compare the accuracy of three types of electronic apex locators (EALs) when two different concentrations of NaOCl irrigation solutions are used by two operators. Materials and Methods: After creating the access cavities for 20 single rooted extracted teeth, the actual canal length (ACL) of each canal was determined visually using a #10 file and magnification. The teeth were subsequently inserted in plastic molds filled with alginate. The electronic measurement of root canal length (EWL) was performed using three different electronic apex locators: Root ZX II, Apex ID, and Dual Pex. Two independent operators, an endodontic specialist with 20 years practice and an undergraduate student in the final year of study, performed the irrigation procedures with two different concentrations of NaOCl (2% and 5.25%), and then measured the EWL using each of the EALs. The accuracy of all EALs, was determined in each case by subtracting the EWL from the ACL. Statistical analyses were performed using one-way ANOVA test. Results: In the presence of 2% NaOCl solution, for a margin error of ±0.5 mm, Root ZX II, Apex ID, and Dual Pex presented an accuracy of 90%, 80%, and 85% respectively. The increase in the concentration of the irrigation solution affected the accuracy of Root ZX II and Apex ID for both operators, diminishing it to 75% for the same margin error, but improved Dual Pex's accuracy to 100%. Conclusions: The best accuracy in working length determination was obtained by Root ZX II for 2% NaOCl solution and by Dual Pex for 5.25% NaOCl solution with no significant statistical difference when compared.

Effectiveness of Different Final Irrigation Procedures on Enterococcus faecalis Infected Root Canals: An In Vitro Evaluation.

This study aimed to evaluate the antibacterial effect of three final irrigation protocols and to compare their ability to remove the smear layer and debris from the root canal. Methods: Sixty-three single-rooted human teeth were inoculated with Enterococcus faecalis for 14 days. The teeth were divided into a positive control group (N = 3) and three treatment groups (N = 20) as follows: final irrigation with saline solution (control group), irrigation with 5.25% NaOCl ultrasonically activated with EndoUltra (EU), standard needle irrigation with Qmix 2in1 (Qx) and irrigation with 5.25% NaOCl activated using SiroLaser Blue (SB). The bacterial load was evaluated by analyzing the colony-forming units (CFU/mL). Selected specimens were split longitudinally and examined using scanning electron microscopy in order to determine the presence of a smear layer and debris. Statistical analyses were performed using one-way ANOVA and the Kruskal−Wallis rank-sum test. Results: Activation of NaOCl with EndoUltra or SiroLaser Blue was superior at reducing intracanal bacteria relative to standard needle irrigation with Qmix 2in1 solution (p < 0.05). Even though SiroLaser Blue showed the best results for removing the smear layer and debris, no significant differences were detected between the groups (p > 0.05). Conclusions: Final irrigation with 5.25% NaOCl ultrasonically activated using EndoUltra or SiroLaser Blue demonstrated a higher efficacy in bacterial reduction than standard needle irrigation with Qmix 2in1.

The effects of thickness and shade on translucency parameters of contemporary, esthetic dental ceramics.

OBJECTIVE: To analyze translucency variations among four different contemporary esthetic ceramic systems having different shades and thicknesses. MATERIAL AND METHODS: Ceramic specimens having different shades and translucencies were tested: leucite reinforced glass-ceramic (ECAD), conventional feldspathic ceramic (Noritake), zirconia reinforced lithium silicate glass-ceramic (Suprinity) and hybrid ceramic (Enamic). Specimens of 0.6, 0.9, 1.2, 1.5 and 2.0-mm thickness (n = 3/group, 615 total) were prepared. Translucency (TP) and Relative Translucency (RTP) Parameters were calculated from spectroradiometric color readings. Effects of shade and thickness for a given system were statistically analyzed using MANOVA and Tukey post-hoc multiple comparisons tests. Translucency variations were assessed comparatively with literature-based perceptibility and acceptability thresholds. RESULTS: TP/RTP values of all ceramic materials decreased with increasing thickness. The most translucent specimens were 0.6-mm thick ECAD HT-A3.5 (TP = 31.99) and ECAD HT-C2 (RTP = 23.75), while the least translucent was 2-mm thick Enamic T-3 M2 (TP = 7.27; RTP = 4.79). Thickness and material type significantly influenced translucency (p < 0.001). Noritake and ECAD LT showed similar translucency values, as well as Suprinity HT and ECAD LT. CONCLUSIONS: For ceramic restorations thicker than 0.9-mm, any thickness increase of 0.3-0.5 mm produces a perceptible but clinically acceptable translucency variation. Increases in thickness larger than 0.6-mm will result in an unacceptable translucency shift. Dental practitioners need to recognize key factors that influence translucency of ceramic restorations in order to choose the optimal material, shade, translucency, and thickness suitable for different clinical scenarios. While shade plays a minor role in translucency variation, ceramic type and restoration thickness significantly affect overall translucency.

Color compatibility between dental structures and three different types of ceramic systems.

BACKGROUND: To assess color compatibility between dental structures (human enamel and dentine) and three different types of ceramic systems. METHODS: Samples (1 and 2 mm-thick) of extracted tooth (containing dentine and enamel areas) and three ceramic systems with different shades and opacities (HT-High Translucent, T-Translucent) were prepared for this study: Vita Suprinity-VS (HT, T; A1, A2, A3, A3.5, B2, C2, D2) (Vita Zahnfabrik); Vita Enamic-VE (HT, T; 1M1, 1M2, 2M2, 3M2) (Vita Zahnfabrik) and Noritake Super Porcelain EX-3-NKT (A1, A2, A3, A3.5, B2, C2, D2) (Kuraray Noritake Dental). Reflectance measurements of all samples were performed over black backgrounds using a non-contact spectroradiometer (SpectraScan PR-670, Photo Research) under a CIE 45°/0° geometry. CIE L*a*b* color parameters were measured and CIELAB/CIEDE2000 color differences (ΔE00/ΔE*ab) and corresponding Coverage Error (CE) of ceramic system for dentine or enamel samples were calculated. Color data was analyzed using one-way ANOVA and post-hoc multiple comparisons tests. CE values were interpreted by comparisons with available 50:50% acceptability color threshold (AT) for dentistry. RESULTS: Statistically significant differences in lightness were found among all ceramic systems and human dentine (p < 0.001), while no significant differences were registered between enamel and VSHT, T and VEHT. 1 mm dentine showed no statistical differences with VST and VSHT for a* coordinate, while 2 mm dentine showed no significant differences (p > 0.05) with VEHT. Thin samples (1 mm) of dentine and enamel showed significant statistical differences (p < 0.05) for b* coordinate with less translucent materials (NKT, VET and VST). For dentine samples, none of the ceramic materials provided a CE lower than AT. VSHT provided the best CE for 1 mm-thick (CE00 = 1.7, CEab = 1.9) and for 2 mm-thick (CE00 = 2.3; CEab = 2.5) enamel samples. CONCLUSIONS: Color coordinates of evaluated esthetic ceramic systems were statistically different from those of human dentine in almost all cases. The evaluated ZrO2 lithium silicate glass-ceramic (VS), with its two levels of translucency, provided lower CE values with human enamel samples while conventional feldspathic ceramic (NKT) and hybrid ceramic systems (VE) demonstrated a better color compatibility with dentin samples.

Shade Correspondence, Color, and Translucency Differences between Human Dentine and a CAD/CAM Hybrid Ceramic System.

OBJECTIVE: To determine the shade correspondence between human dentine and two versions of a CAD/CAM hybrid ceramic system and to investigate color and translucency differences between these materials. MATERIALS AND METHODS: Twenty-four samples of different shades and opacities were fabricated from Vita Enamic CAD/CAM ceramic blocks. Human dentine samples were obtained from 73 extracted maxillary teeth. Color coordinates of all samples were measured using VitaEasyshade spectrophotometer. The translucency parameter (TP) and ΔEab* and ΔE00 color differences, with respect to human dentine of anterior and posterior teeth, were calculated. RESULTS: Vita Enamic Translucent was the best match for anterior teeth (>90% of cases) while Vita Enamic T 3M2 was the best option for the dentine samples of posterior teeth in 78.8% ( ΔEab*) and 54.5% ( ΔE00) of the cases. The smallest differences in translucency ( ΔTP) with the dentine samples of anterior teeth were obtained for Vita Enamic T 3M2 (92.5%) and with those of posterior teeth for Vita Enamic HT 1M2 (45.4%). CONCLUSIONS: VITA Enamic Translucent is the best option as color match for both anterior and posterior teeth dentine. In terms of translucency, VITA Enamic Translucent closely matched anterior teeth dentine while for posterior teeth, VITA Enamic HT was the best option. CLINICAL SIGNIFICANCE: The results of the present study could help clinicians in their decision of choosing a specific shade and translucency for their anterior or posterior esthetic restorations with hybrid ceramics. (J Esthet Restor Dent 28:S46-S55, 2016).

Dentine scattering, absorption, transmittance and light reflectivity in human incisors, canines and molars.

OBJECTIVES: To evaluate, using Kubelka-Munk reflectance theory, the scattering (S), absorption (K), transmittance (T) and light reflectivity (RI) of incisors, canines and molars human dentine. METHODS: Eighty-one human teeth (incisors, canines and molars) were used in this study. All teeth crowns were sectioned using a water-cooled diamond saw at low speed. The obtained dentine samples were polished to a final thickness of 2mm. The relative spectral radiance was measured against black and white backgrounds, using a spectroradiometer in a viewing cabinet with D65 illuminant. Kubelka-Munk equations were used to calculate the scattering and absorption coefficients, transmittance and light reflectivity. Kruskal-Wallis rank sum test was performed to compare the mean values of Kubelka-Munk coefficients of human incisors, canines and molars dentine samples followed by Kruskal-Wallis multiple comparison tests for pairwise comparisons. RESULTS: The spectral behavior of S, T and RI exhibited similar trends for all three types of dentine samples. However, highly significant differences (p<0.001) were found between their magnitudes in the three types of dentine samples (p<0.001). Only the magnitudes of the K coefficients were found to be similar (p=0.235) between incisors, canines and molars. Canine's dentine samples showed highest S and RI values, while human molars dentine samples exhibited highest K and T values. CONCLUSIONS: Within the limitations of this study, the optical properties of human dentine are strongly influenced by the type of tooth. The results of the present study can be used as reference in the development of aesthetic dental restorative materials. CLINICAL IMPLICATIONS: The significant differences identified in the optical behavior of the dentine from the three types of teeth have to be taken into consideration by the dentist and the dental technician when pursuing biomimetics with any restorative material in esthetic dentistry.

Spectrophotometric color evaluation of permanent incisors, canines and molars. A cross-sectional clinical study.

BACKGROUND AND AIMS: An accurate color reproduction represents the final validation level of an esthetic anterior or posterior restoration. The aim of this study was to evaluate the color of permanent maxillary incisors, canines and molars, using a clinical spectrophotometer. METHODS: The Vita Easyshade Advance 4.0(®) intraoral spectrophotometer was used by one clinician to determine the color of 369 permanent maxillary incisors, canines and molars. The best matches to Vitapan Classical(®) and 3D-Master(®) shade guides were recorded. A one-way analysis of variance and Kruskal-Wallis test were used to compare L*, a*, b*, c* and h* color coordinates among the 3 types of teeth. Differences between the mean values of all color coordinates were evaluated by use of Bonferroni corrections. Color difference (ΔE*) between incisors, canines and molars was calculated from ΔL*, Δa* and Δb* data and the results were compared to ΔE*=3.3 acceptability threshold. RESULTS: Except for Δa* and Δh* between canines and molars, statistically significant differences among the mean differences of all color coordinates were found when the 3 types of teeth were compared by pairs. The most frequently measured shades were A1 (48.4%), respectively 1M1 (31.5%) for incisors, B3 (36.6%), respectively 2M3 (39.8%) for canines and B3 (44.7%), respectively 2M3 (52%) for molars. Incisors had the highest lightness values, followed by canines and molars. Molars were the most chromatic with the highest a* and b* values. CONCLUSIONS: Despite the limitations of this study, color differences among incisors, canines and molars were found to be statistically significant, above the clinical acceptability threshold established. In conclusion, successful esthetic restorations of permanent teeth of the same patient need an individual color assessment and reproduction of every type of tooth.

Patients' perspective on dental aesthetics in a South-Eastern European community.

OBJECTIVES: To assess the importance attributed to dental aesthetics by subjects from a Romanian community. In addition, the role played by dental color, the group-distributions based on the self-evaluation of dental color and the previous experience regarding whitening treatments are analysed. METHODS: A multiple-choice questionnaire was administered to 540 patients in dental offices in Cluj-Napoca, Romania; the subjects were also asked to self-evaluate their dental shade, using a set of images as a comparison. Answers to the questionnaires were statistically analysed using Microsoft Excel and SPSS 13.00 (Pearson's chi-square test, Fisher's exact test, Kendall's tau b). RESULTS: From the participants, 17.96% were motivated by aesthetic reasons to ask for treatment; most of the patients evaluated their smile as "acceptable" (38.51%) or "having some defects" (29.44%) and were self-included in groups of medium and dark shades (33.7% and 33.89%, respectively). Whilst 22.40% of the subjects considered the dental color as being the most evident defect of their dentition, 39.07% indicated a self-perception of "an abnormal dental shade". A strong correlation between darker self-assessed tooth color-groups and the self-perception of an abnormal tooth color was found (Chi square p≪0.001, Kendall's tau-c=0.44, with p≪0.001). Previous whitening treatments were reported by 8.88% of the subjects. CONCLUSIONS: Among patients who wanted to improve one of their oral functions, the majority requested changes in aesthetics. Dental shade is one of the aspects recognized as problematic by the participants, but nonetheless the percentage of patients who had previously benefited by whitening treatments was moderate.

A comparison between a new visual method of colour matching by intraoral camera and conventional visual and spectrometric methods.

OBJECTIVES: The objective of this study was to evaluate the new colour-matching Sopro Shade concept of the Sopro 717(®) intraoral camera (assisted visual evaluation method) by comparing it with the Vita 3DMaster(®) shade guide under the True Shade(®) lamp and the Vita Easyshade(®) spectrophotometric method. METHODS: The basic colour of the maxillary right central incisor and canine of 38 participants was determined by three examiners then repeated the next day using the three evaluation methods. Two examiners were experienced clinicians and one was a Sopro intraoral camera engineer. The Vita 3D-Master shade guide was used with all three colour-matching methods. Kendall's tau-b correlation coefficients between the different series of tooth-colour evaluations were computed and two-tailed t-tests for paired samples were applied. RESULTS: Regardless of the tooth examined, significant intra-examiner agreement (p < 0.05) occurred between the visual and the assisted visual methods. Inter-examiner reliability was higher for canines than for central incisors, for all three methods. When comparing the two visual assessments with the spectrophotometric one, Kendall's tau-b correlation coefficients were lower. When comparing the two visual methods, significant agreement (p < 0.05) was found for both canines and central incisors. CONCLUSIONS: Within the limitations of this study, the Sopro Shade concept of the Sopro 717 intraoral camera is a reliable assistance to visual colour assessment compared with conventional visual methods. The reproducibility and reliability of all methods and examiners' measurements for canines were generally higher than those for central incisors. The possible clinical impact of the lower level of agreement between the two visual methods (conventional and assisted) compared with spectrophotometry should be studied further.