Effect of digitization parameters on periapical radiographic image quality with regard to anatomic landmarks

The aim of this study was to evaluate the influence of digitization parameters on periapical radiographic image quality, with regard to anatomic landmarks. Digitized images (n = 160) were obtained using a flatbed scanner with resolutions of 300, 600 and 2400 dpi. The radiographs of 2400 dpi were decreased to 300 and 600 dpi before storage. Digitizations were performed with and without black masking using 8-bit and 16-bit grayscale and saved in TIFF format. Four anatomic landmarks were classified by two observers (very good, good, moderate, regular, poor), in two random sessions. Intraobserver and interobserver agreements were evaluated by Kappa statistics. Inter and intraobserver agreements ranged according to the anatomic landmarks and resolution used. The results obtained demonstrated that the cement enamel junction was the anatomic landmark that presented the poorest concordance. The use of black masking provided better results in the digitized image. The use of a mask to cover radiographs during digitization is necessary. Therefore, the concordance ranged from regular to moderate for the intraobserver evaluation and concordance ranged from regular to poor for interobserver evaluation.

Cárie oculta extensa: relato de caso clínico

The pattern of caries lesions has been modified over decades. If the presence or absence of a caries lesion is based upon only a visual examination, its diagnosis might become underestimated since dentinal lesions underneath non cavitated or minimally demineralized enamel is highly frequent in dental clinics. The aim of this paper is to report a clinical case of a child with an upper molar with questionable occlusal aspect, presenting asymptomatic pulpal hyperplasia on the distolingual pit. Periapical radiographic examination was essential for diagnosing hidden caries and elaborating the treatment plan. As part of the approach, removal of the decayed tissue and pulpotomy with calcium hydroxide were performed. The association of an accurate visual examination to an adequate oral radiographyis is extremely important in cases which the presence of hidden caries is doubtful. As a result, an early diagnosis and the reduction of more invasive interventions related to the oral health care of pediatric patients can be achieved as well.

Hipomineralización incisivo Y molar: diagnóstico diferencial

Hypomineralized first molar often in combination with hypomineralized incisors (MIH - molar incisor hypomineralization) is a common finding in everyday practice. In this condition, hypomineralized dental enamel is fragile and soft, and it can break easily leading to an exposed dentin, and causing dental sensitivity and progression of caries lesions. The prevalence of MIH range from 3.6 to 25% in North of Europe that consider this condition a public health problem. No conclusive information was reported about the etiologic factors of MIH, however, systemic causes seem to be of importance. Several aetiological factors are mentioned as the cause of this condition and they are frequently associated with complications during pregnancy and childhood diseases during the first three years of life. MIH is frequently misinterpreted as fluorosis, hypoplasia or amelogénesis imperfect, however, this condition presents defined clinical aspects that can distinct it from the other defects.

Low toxic effects of a whitening strip to cultured pup cells

Fundacao de Amparo a Pesquisa do Estado de sao Paulo (FAPESP)

Immediate and late analysis of dental pulp stem cells viability after indirect exposition to alternative in-office bleaching strategies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vitro performance of a pen-type laser fluorescence device and bitewing radiographs for approximal caries detection in permanent and primary teeth

To evaluate the performance of a pen‑type laser fluorescence device (DIAGNOdent 2190; LFpen, KaVo, Germany) and bitewing radiographs (BW) for approximal caries detection in permanent and primary teeth. Materials and Methods: A total of 246 anterior approximal surfaces (102 permanent and 144 primary) were selected. Contact points were simulated using sound teeth. Two examiners assessed all approximal surfaces using LFpen and BW. The teeth were histologically assessed for the reference standard. Optimal cut‑off limits were calculated for LFpen for primary and permanent teeth. Sensitivity, specificity, accuracy and area under the receiver operating characteristic curve (Az) were calculated for D1 (enamel and dentin lesions) and D3 (dentin lesions) thresholds. The reproducibility was assessed by intraclass correlation coefficient (ICC) and Cohen's weighted kappa values. Results: For permanent teeth, the LFpen cut‑off were 0– 27 (sound), 28– 33 (enamel caries) and >33 (dentin caries). For primary teeth, the LFpen cut‑off were 0– 7 (sound), 8– 32 (enamelcaries) and >32 (dentin caries). The LFpen presented higher sensitivity values than BW for primary teeth (0.58 vs. 0.32 at D1 and 0.80 vs. 0.47 at D3) and permanent teeth (0.80 vs. 0.57 at D1 and 0.94 vs. 0.51 at D3). Specificity did not show a significant difference between the methods. Rank correlations with histology were 0.59 and 0.83 (LFpen) and 0.36 and 0.70 (BW) for primary and permanent teeth, respectively, considering all lesions. ICC values for LFpen were 0.71 (inter) and 0.86 (intra) for permanent teeth and 0.94 (inter) and 0.90/0.99 for primary teeth. Kappa values for BW were 0.69 (inter) and 0.68/0.90 (intra) for permanent teeth and 0.64 (inter) and 0.89/0.89 for primary teeth. Conclusion: LFpen presented better reproducibility for primary and permanent teeth and higher accuracy in detecting caries lesions at D1 threshold than BW for permanent teeth. LFpen should be used as an adjunct method for approximal caries detection.

Indirect cytocompatibility of a low-concentrated hydrogen peroxide bleaching gel to odontoblast-like cells

Aim To assess the initial cytotoxicity and the late phenotype marker expression of odontoblast-like cells (MDPC-23) subjected to less aggressive in-office bleaching therapies. Methodology A 17.5% hydrogen peroxide (H2O2) gel was applied for 45, 15 or 5 min to enamel/dentine discs adapted to trans-wells positioned over cultured MDPC-23 cells. No treatment was performed on the negative control. Immediately after bleaching, the cell viability, gene expression of inflammatory mediators and quantification of H2O2 diffusion were evaluated. The ALP activity, DSPP and DMP-1 gene expression and mineralized nodule deposition (MND) were assessed at 7, 14 or 21 days post-bleaching and analysed statistically with Mann–Whitney U-tests (α = 5%). Results H2O2 diffusion, proportional to treatment time, was observed in all bleached groups. Reductions of approximately 31%, 21% and 13% in cell viability were observed for the 45-, 15- and 5-min groups, respectively. This reduction was significant (P < 0.05) for the 45- and 15-min groups, which also presented significant (P < 0.05) over-expression of inflammatory mediators. The 45-min group was associated with significant (P < 0.05) reductions in DMP-1/DSPP expression at all periods, relative to control. The ALP activity and MND were reduced only in initial periods. The 15-min group had less intense reduction of all markers, with no difference to control at 21 days. Conclusions The 17.5% H2O2 applied to tooth specimens for 5 min caused no alteration in the odontoblast-like cells. When this gel was applied for 45 or 15 min, a slight cytotoxicity, associated with alterations in phenotypic markers, was observed. However, cells were able to recover their functions up to 21 days post-bleaching.

Responses of dental pulp cells to a less invasive bleaching technique applied to adhesive restored teeth

To assess the cytotoxicity of 35% hydrogen peroxide (HP) bleaching gel applied for 15 min to sound or restored teeth with two-step self-etching adhesive systems and composite resin. Materials and Methods: Sound and restored enamel/dentin disks were stored in water for 24 h or 6 months + thermocycling. The disks were adapted to artificial pulp chambers and placed in compartments containing culture medium. Immediately after bleaching, the culture medium in contact with dentin was applied for 1 h to previously cultured odontoblast-like MDPC-23 cells. Thereafter, cell viability (MTT assay) and morphology (SEM) were assessed. Data were analyzed by two-way ANOVA and Tukey's test (a = 5%). Results: In comparison to the negative control group (no treatment), no significant cell viability reduction occurred in those groups in which sound teeth were bleached. However, a significant decrease in cell viability was observed in the adhesive-restored bleached groups compared to negative control. No significant difference among bleached groups was observed with respect to the presence of restoration and storage time. Conclusion: The application of 35% HP bleaching gel to sound teeth for 15 min does not cause toxic effects in pulp cells. When this bleaching protocol was performed in adhesive-restored teeth, a significant toxic effect occurred.

Variáveis que afetam o procedimento de colagem direta ortodôntica: braquetes e materiais adesivos

Following the introduction of the acid-etching technique in enamel surface, direct attachment of orthodontic appliances on the surface of the tooth and/or restorations became a routine procedure in the assembly of the fixed devices. The attainment of a success result is related to the criterion attention to the details and the steps of the bonding technique, as well as, to the knowledge of the characteristics of the adhesive materials and orthodontic brackets. This paper presents some aspects of various types of brackets and adhesives materials.

Variáveis que afetam o procedimento de colagem direta ortodôntica: procedimentos clinicos

Direct bonding of orthodontics attachments to the teeth or restoration has become a routine in fixed appliance therapy. The technique used seems to be simple, but meticulous attention to detail and steps, a thorough understanding of factors involved are needed to ensure a successful outcome into different surfaces. It is the purpose of this article to review concerning aspects to orthodontic bonding in enamel and restorations fabricated from different materials; affording assistance to the reader wiser accomplishment and successful procedure.

Hipomineralização Molar Incisivo (HMI): avaliação clínica e microscópica

This study aimed to evaluate the clinical and microscopic changes of MIH, and compare them to areas of healthy dental enamel. Methodology: epoxy resin replicas of healthy incisors and affected by MIH were evaluated qualitatively by scanning electron microscopy (SEM) photographs. Results: Clinically it was observed that MIH incisors showed changes in color and surface, with significant structural losses. By SEM, these had irregular surfaces and margins with structural losses. Conclusions: The teeth affected by HMI have clinical and morphological characteristics that are important for the definition of patient's treatment plan.

The performance of conventional and fluorescence-based methods for occlusal caries detection: an in vivo study with histological validation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Efeito citotóxico de agentes clareadores a base de peróxido de hidrogênio a 20% e 38% sobre células odontoblastóides

The aim of this in vitro study was to evaluate the trans-enamel and transdentinal cytotoxic effects of two in-office tooth bleaching techniques that employ bleaching gels containing 20% and 38% of H2 O2 on cultured odontoblast-like cell line (MDPC-23). Sixty enamel/dentin discs were obtained from bovine central incisors and placed individually in artificial pulp chambers. Six groups were formed according to the following enamel treatments: G1- 20% H2 O2 (1 application); G2- 20% H2 O2 (2 applications); G3- 38% H2 O2 (1 application); G4- 38% H2 O2 (2 applications); G5- 38% H2 O2 (3 applications); and G6- control (no treatment). In G1 and G2, the bleaching gel was left in contact with the enamel surface for 45 min in each application. However, in G3, G4, and G5 the bleaching gel was applied for only 10 min per application. After the last application, the extracts were collected and applied on previously cultured cells (30.000 cells/cm2 ) for 24 h. Cell metabolism was evaluated by the MTT assay and cell morphology was analysed by scanning electron microscopy. Cell metabolism decreased by 96.29%; 96.11%; 96.42%; 95.62%; and 97.18% in G1, G2, G3, G4, and G5, respectively. All treated groups differed significantly from non-treated control group (G6) (p < 0.05). However, the difference in cell metabolism among treated groups was not significant statistically. In addition, significant morphological cell alterations were observed in all treated groups. Under the tested experimental conditions, the extracts collected after both tooth bleaching techniques evaluated in this study caused severe toxic effects on cultured odontoblast-like cell MDPC-23.

Esthetic and function improvement by direct composite resins and biomimetic concept

Aim: This case report describe a resin layering restorative technique based on biomimetic concept to improve esthetics in a patient with dental defects that affected both enamel and dentin in anterior teeth. Background: Severe structural defect in anterior teeth compromises esthetics and it is a high challenge to become the defect imperceptible after the restoration. Case description: A clinical sequence of applying different composite resin layers allowed the reproduction of the interaction between hard dental tissues and the restorative material. Conclusion: This technique achieved a satisfactory final esthetic outcome, preserving sound teeth structure and at same time, improved the quality of life of the young patient. Clinical significance: The utilization of the biomimetic concept to increase a disharmonic smile with dental defects is based in a conservative approach, which reached a satisfactory and esthetic outcome.

Tratamento do sorriso gengival: como estabelecer proporção e harmonia

The etiology of gingival smile is multifactorial and the correct diagnosis eill determine a successful treatment planning. Altered passive eruption occurs during the final stages of tooth eruption, when apical migration of the periodontal tissues does not occur, resulting in a distance > 2mm between the alveolar crest and the cement-enamel juncrion. This change leads to the shortening of the clinical crown and even further may lead to excessive gingival exposure. For treatment, there is a necessity for the combined removal of gingiva and bone tissue. This article discusses the literature on the issue and reports a case where periodontal plastic surgery was performed for the correcrion of a gingival smile.