Núbia Inocencya Pavesi Pini

Advances in dental veneers: materials, applications, and techniques

Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient. Clinicians should understand the latest ceramic materials in order to be able to recommend them and their applications and techniques, and to ensure the success of the clinical case. The current literature was reviewed to search for the most important parameters determining the long-term success, correct application, and clinical limitations of porcelain veneers.

Enamel microabrasion: An overview of clinical and scientific considerations

Superficial stains and irregularities of the enamel are generally what prompt patients to seek dental intervention to improve their smile. These stains or defects may be due to hypoplasia, amelogenesis imperfecta, mineralized white spots, or fluorosis, for which enamel microabrasion is primarily indicated. Enamel microabrasion involves the use of acidic and abrasive agents, such as with 37% phosphoric acid and pumice or 6% hydrochloric acid and silica, applied to the altered enamel surface with mechanical pressure from a rubber cup coupled to a rotatory mandrel of a low-rotation micromotor. If necessary, this treatment can be safely combined with bleaching for better esthetic results. Recent studies show that microabrasion is a conservative treatment when the enamel wear is minimal and clinically imperceptible. The most important factor contributing to the success of enamel microabrasion is the depth of the defect, as deeper, opaque stains, such as those resulting from hypoplasia, cannot be resolved with microabrasion, and require a restorative approach. Surface enamel alterations that result from microabrasion, such as roughness and microhardness, are easily restored by saliva. Clinical studies support the efficacy and longevity of this safe and minimally invasive treatment. The present article presents the clinical and scientific aspects concerning the microabrasion technique, and discusses the indications for and effects of the treatment, including recent works describing microscopic and clinical evaluations.

Digital Analysis of Anterior Dental Esthetic Parameters in Patients with Bilateral Maxillary Lateral Incisor Agenesis

OBJECTIVE To analyze anterior dental esthetic parameters-width/height ratio (WHR), gingival zenith (GZ), and apparent contact dimension (ACD)-in patients with maxillary lateral incisor agenesis (MLIA) bilaterally treated with space closure and recontouring of the canines, or with implant-supported prostheses. METHODS Fifty-two participants were allocated into three groups as follows: MLIA patients (N = 18) treated with teeth recontouring (RG); MLIA patients (N = 10) treated with implants (IG); and volunteers without agenesis (N = 24), who served as controls (CG). Dental casts of all patients were obtained and electronically scanned. Digital images were analyzed with 3Shape A/S OrthoAnalyser software (Copenhagen, Denmark). Shapiro-Wilk test, Spearman correlation, and Kruskal-Wallis statistical tests (p < 0.05) were used for statistical analysis. RESULTS Although IG presented smaller means when compared with RG and CG, no statistical differences were found for WHR among groups (p > 0.05). Concerning GZ, RG presented more discrepancies than IG and CG, with statistically significant differences (p = 0.0165). IG presented statistically significant differences for the ACD in comparison with RG and CG (p < 0.05). CONCLUSION Based on the results of this study, patients treated with space closure and teeth recontouring (RG) were shown to be closest to patients without agenesis (CG) in relation to the anterior dental esthetic parameters evaluated. CLINICAL SIGNIFICANCE The digital analysis of esthetic principles, such as those investigated in this study involving maxillary incisor agenesis, is paramount to successful esthetic treatment planning. The results of the present study, as well as those found in the literature, indicate that clinicians should use esthetic parameters, such as those investigated herein, when treatment planning extensive oral rehabilitation cases.

Congenitally missing maxillary lateral incisors: functional and periodontal aspects in patients treated with implants or space closure and tooth re-contouring.

To evaluate functional and periodontal aspects in patients with unilateral or bilateral congenitally missing maxillary lateral incisors, treated with either implants or space closure and tooth re-contouring. The sample consisted of 68 volunteers, divided into 3 groups: SCR - space closure and tooth re-contouring with composite resin (n = 26); SOI – implants placed in the area of agenesis (n = 20); and CG - control group (n = 22). A modified Helkimo questionnaire and the Research Diagnostic Criteria for Temporomandibular Disorders were used by a single, previously calibrated evaluator to assess signs and symptoms of temporomandibular joint disorder. The periodontal assessment involved the following aspects: plaque index, bleeding upon probing, pocket depth greater than 3 mm, gingival recession, abfraction, periodontal biotype and papilla index. The data were analyzed using Fishers exact test and the nonparametric Mann-Whitney and Kruskal-Wallis tests (α=.05). No differences in periodontal status were found between treatments. None of the groups were associated with signs and symptoms of temporomandibular joint disorder. Both treatment alternatives for patients with congenitally missing maxillary lateral incisors were satisfactory and achieved functional and periodontal results similar to those of the control group.

Influence of coffee and red wine on tooth color during and after bleaching

Abstract Objective. The aim of this study was to evaluate the influence of coffee and red wine staining on tooth color during and after bleaching. Materials and methods. Blocks obtained from human molars were divided into 11 groups (n = 5) in accordance with the bleaching treatment—peroxide carbamide 10%, 15% or 20%—and in accordance with the stain therapy—coffee, wine or without staining (control). Color change analysis was performed by photo-reflectance using a spectrophotometer, during (3-times/week) and after (7, 15 and 30 days) the bleaching treatment. During the experiment, the samples were stored in artificial saliva. The results were submitted to statistical analysis with the Dunnet and Tukey tests (p < 0.05). Results. The concentrations of carbamide peroxide (10%, 15% and 20%) did not differ significantly from the control group during bleaching (up to the 22nd day), with (Tukey, p > 0.05) or without storage in pigment solution. After the bleaching, there were statistically significant differences between the groups treated with coffee (30th day) and wine (7th and 30th days) relative to the control, which was treated with whitening agents. Conclusion. During bleaching, remineralization of the enamel with artificial saliva and the subsequent bleaching session were effective in preventing enamel staining. After the whitening procedures, both stain therapies—coffee and wine—caused enamel color changes; however, the wine led to greater staining than did coffee.

Congenitally Missing Maxillary Lateral Incisors: Update on the Functional and Esthetic Parameters of Patients Treated with Implants or Space Closure and Teeth Recontouring

Maxillary lateral incisor agenesis (MLIA) is a condition that affects both dental esthetics and function in young patients, and represents an important challenge for clinicians. Although several treatment options are available, the mesial repositioning of the canines followed by teeth recontouring into lateral incisors; or space opening/maintenance followed by implant placement have recently emerged as two important treatment approaches. In this article, the current and latest literature has been reviewed in order to summarize the functional and esthetic outcomes obtained with these two forms of treatment of MLIA patients in recent years. Indications, clinical limitations and the most important parameters to achieve the best possible results with each treatment modality are also discussed. Within the limitations of this review, it is not possible to assert at this point in time that one treatment approach is more advantageous than the other. Long-term followup studies comparing the existing treatment options are still lacking in the literature, and they are necessary to shed some light on the issue. It is possible, however, to state that adequate multidisciplinary diagnosis and planning are imperative to define the treatment option that will provide the best individual results for patients with MLIA.

In vitro effects of hydrogen peroxide combined with different activators for the in-office bleaching technique on enamel

Abstract Objective. The aim of this study was to evaluate the alteration of human enamel bleached with high concentrations of hydrogen peroxide associated with different activators. Materials and methods. Fifty enamel/dentin blocks (4 × 4 mm) were obtained from human third molars and randomized divided according to the bleaching procedure (n = 10): G1 = 35% hydrogen peroxide (HP – Whiteness HP Maxx); G2 = HP + Halogen lamp (HL); G3 = HP + 7% sodium bicarbonate (SB); G4 = HP + 20% sodium hydroxide (SH); and G5 = 38% hydrogen peroxide (OXB – Opalescence Xtra Boost). The bleaching treatments were performed in three sessions with a 7-day interval between them. The enamel content, before (baseline) and after bleaching, was determined using an FT-Raman spectrometer and was based on the concentration of phosphate, carbonate, and organic matrix. Statistical analysis was performed using two-way ANOVA for repeated measures and Tukey’s test. Results. The results showed no significant differences between time of analysis (p = 0.5175) for most treatments and peak areas analyzed; and among bleaching treatments (p = 0.4184). The comparisons during and after bleaching revealed a significant difference in the HP group for the peak areas of carbonate and organic matrix, and for the organic matrix in OXB and HP+SH groups. Tukey’s analysis determined that the difference, peak areas, and the interaction among treatment, time and peak was statistically significant (p < 0.05). Conclusion. The association of activators with hydrogen peroxide was effective in the alteration of enamel, mainly with regards to the organic matrix.

The effect of hydrofluoric acid concentration and heat on the bonding to lithium disilicate glass ceramic

The aim of this study was to evaluate the effects of hydrofluoric acid (HF) concentration and previous heat treatment (PHT) on the surface morphology and micro-shear bond strength (mSBS) of a lithium disilicate glass ceramic (EMX) to resin cement. One hundred four EMX specimens were randomly assigned to two groups (n=52) according to the HF concentration: 5% and 10%. A new random distribution was made according to the PHTs (n=13): control (no PHT); previously heated HF (70 °C); previously heated EMX surface (85 °C); the combination of heated HF + heated EMX surface. The etching time was set at 20 s. All EMX blocks were silanated and received a thin layer of an unfilled resin. Five resin cement cylinders were made on each EMX surface using Tygon tubes as matrices, and then stored for 24 h at 37 °C. One random etched EMX sample from each group was analyzed using field-emission scanning electron microscopy (FE-SEM). The data were subjected to two-way ANOVA and multiple comparisons were performed using the Tukey post hoc test (a=0.05). For the control groups, 5% HF showed statistically lower mSBS values when compared to 10% HF (p<0.05). PHT increased the mSBS values for 5% HF, yielding statistically similar results to non-PHT 10% HF (p<0.05). FE-SEM images showed increased glassy matrix removal when PHT was applied to HF 5%, but not to the same degree as for 10% HF. PHT has the potential to improve the bond strength of 5% HF concentration on lithium disilicate glass ceramic.

Analysis of width/height ratio and gingival zenith in patients with bilateral agenesis of maxillary lateral incisor

OBJECTIVE: The purpose of this study was to evaluate the width/length ratio and the gingival zenith (GZ), by means of dental casts and digital caliper, in patients with missing maxillary lateral incisors after treatment. METHODS: The sample was composed of 52 subjects divided into 3 groups: BRG (n = 18), patients with bilateral agenesis treated with tooth re-contouring; BIG (n = 10) patients with agenesis treated with implants and CG (n = 24), control group. The data were analyzed using Shapiro-Wilk, Spearman correlation, Wilcoxon, Kruskal-Wallis, t test and ANOVA tests (p 0.05). GZ data for the right and left sides of the smile were not considered statistically different. CONCLUSION: Although no statistical difference was found in the comparison between the groups, analysis of the descriptive values showed that group BIG showed the greatest difference in values with regard to width/length ratio. Regarding gingival zenith, BRG showed the greatest difference.

Enamel morphology after microabrasion with experimental compounds.

Background: Enamel microabrasion is an esthetic treatment for removing superficial stains or defects of enamel. Aim: This study evaluated the roughness after enamel microabrasion using experimental microabrasive systems. Materials and Methods: One hundred and ten samples (5 × 5 mm) were obtained from bovine incisors and divided into 11 groups (n = 10) in accordance with the treatment: Microabrasion using 6.6% hydrochloric acid (HCl) or 35% phosphoric acid (H 3 PO 4 ) associated with aluminum oxide (AlO 3 ) or pumice (Pum) with active application (using rubber cup coupled with a micro-motor of low rotation) or passive application (just placing the mixture on the enamel surface); just the use of acids in a passive application (negative control), and a group without treatment (positive control). Roughness analysis was performed before and after treatments. The statistical analysis used analysis of variance (PROC MIXED), Tukey-Kramer and Dunnet tests (P < 0.05). Representative specimens were evaluated using scanning electron microscopy (SEM). Results: There was no significant difference between the acids used (P = 0.0510) and the applications (P = 0.8989). All of the treated groups were statistically different from the positive control. When using passive application, the use of HCl + AlO 3 resulted in higher roughness when compared with HCl + Pum. Additionally, this treatment was statistically different from the passive application of H 3 PO 4 (negative control) (P < 0.05). However, SEM analysis showed that the treatment with AlO 3 resulted in an enamel surface with a more polished aspect when compared with Pum. Conclusion: AlO 3 may be a suitable particle for use in microabrasive systems.