Prosthetic laboratory influence on the vertical misfit at the implant/UCLA abutment interface

An inadequate fit at the abutment/implant interface can generate mechanical and biological problems. The laboratorial stages could induce misfit in such interface when the castable UCLA abutment type is used. The purpose of this study was to comparatively evaluate the performance of three prosthetic laboratories (Labs A, B and C) by vertical fit analysis of castable UCLA abutments on the casting and soldering stages of the same prosthesis. Four fixed prostheses were built by each laboratory using castable UCLA abutments. The evaluation was made by scanning electron microscopy under 500x magnification in the mesial and distal regions of each element of the prosthesis, totalizing 24 measurements per laboratory. The results were analyzed statistically by Kruskal-Wallis test (p<0.05). In the casting process, the values presented by the laboratories differed significantly to each other (p=0.004). After soldering, the values presented by the laboratories showed no significant difference (p=0.948). It may be concluded that the fit values obtained in the casting stage of UCLA abutments can be influenced when processed by different laboratories, and that conventional soldering itself increased the degree of framework misfit, regardless of which laboratory made it.     

Salivary cortisol and dehydroepiandrosterone (DHEA) levels, psychological factors in patients with oral lichen planus

Objective

The aim of this study was to determine the salivary levels of dehydroepiandrosterone (DHEA) and cortisol and scores of depression, anxiety and stress in patients with oral lichen planus (OLP).

Study design

Thirty-one patients with a diagnosis of OLP were selected; they were matched by sex and age with 31 control patients. Symptoms of depression, anxiety and stress were investigated by the instruments Beck Depression Inventory, Beck Anxiety Inventory and Lipp's Inventory of Stress Symptoms for Adults, respectively. Saliva was collected in the morning and at night for the determination of DHEA and cortisol levels by radioimmunoassay.

Results

There was no significant difference between the groups with respect to depression (P = 0.832), anxiety (P = 0.061) or stress (P = 0.611), or with respect to morning and night salivary levels of DHEA (P = 0.888, P = 0.297) and cortisol (P = 0.443, P = 0.983).

Conclusions

The results suggest an association of OLP with anxiety. However, DHEA and cortisol levels did not differ between groups, which does not support any neuroendocrine aetiology for OLP.     

Preliminary clinical reports of a novel night-guard tooth bleaching technique modified by casein phosphopeptide-amorphous calcium phosphate (CCP-ACP)

Although supervised night-guard bleaching has proved successful for whitening teeth, both mineral loss and tooth sensitivity are still common problems. The present study introduces a novel remineralizer as well as describes the utilization of a possibly low sensitivity supervised night-guard vital tooth bleaching technique. A 22% carbamide peroxide gel was mixed with the casein phosphopeptide-amorphous calcium phosphate-containing MI Paste. The peroxide/MI Paste mixture was prepared with 1 ml of each material until obtaining a homogeneous paste. Five patients were instructed to follow a home bleaching protocol for 3 weeks. The outcome was assessed visually with a Vitapan scale. All subjects presented reduction of at least two Vitapan scale units after bleaching and no sensitivity was reported. The concomitant use of MI Paste and peroxide might not affect the gel effectiveness and still reduce hypersensitivity levels.     

Congenital infantile fibromatosis of the cheek: report of a rare case and differential diagnosis

Infantile fibromatosis is a benign tumour that consists of dense masses of fibroblasts and myofibroblasts with marked collagen production. Although it is a nonmetastasising tumour, it has significant potential for local invasion and recurrence and may be fatal because of its size and location. The authors report an unusual case of infantile fibromatosis of the cheek in an 8-month-old boy, present since birth. The patient underwent surgical treatment with tumour-free margins and the 6-month follow-up revealed no signs of recurrence. Infantile fibromatosis of the cheek is a very rare condition at this location, especially congenital cases. It should be considered in the differential diagnosis of congenital lesions in childhood.     

Morphogenesis and bone integration of the mouse mandibular third molar

The mouse third molar (M3) develops postnatally and is thus a unique model for studying the integration of a non-mineralized tooth with mineralized bone. This study assessed the morphogenesis of the mouse M3, related to the alveolar bone, comparing M3 development with that of the first molar (M1), the most common model in odontogenesis. The mandibular M3 was evaluated from initiation to eruption by morphology and by assessing patterns of proliferation, apoptosis, osteoclast distribution, and gene expression. Three-dimensional reconstruction and explant cultures were also used. Initiation of M3 occurred perinatally, as an extension of the second molar (M2) which grew into a region of soft mesenchymal tissue above the M2, still far away from the alveolar bone. The bone-free M3 bud gradually became encapsulated by bone at the cap stage at postnatal day 3. Osteoclasts were first visible at postnatal day 4 when the M3 came into close contact with the bone. The number of osteoclasts increased from postnatal day 8 to postnatal day 12 to form a space for the growing tooth. The M3 had erupted by postnatal day 26. The M3, although smaller than the M1, passed through the same developmental stages over a similar time span but showed differences in initiation and in the timing of bone encapsulation.     

The Caries Assessment Spectrum and Treatment (CAST) index: rational and development

Serious difficulties in reporting results were encountered when using ICDAS II and PUFA separately in an epidemiological survey in a child population in Brazil. That necessitated the development of a comprehensive but pragmatic caries assessment index. This publication describes the rationale, development and content of a novel caries assessment index. Strengths and weaknesses of ICDAS II, PUFA and other indices were analysed. The novel caries index developed for use in epidemiological surveys is termed 'Caries Assessment Spectrum and Treatment' (CAST). 'Spectrum' indicates what is considered the main strength of the new index - its usefulness in describing the complete range of stages of carious lesion progression: from no carious lesion, through caries protection (sealant) and caries cure (restoration) to lesions in enamel and dentine, and the advanced stages of carious lesion progression in pulpal and tooth-surrounding tissue. CAST combines elements of the ICDAS II and PUFA indices, and the M- and F-components of the DMF index. A DMF score can easily be calculated from the CAST score, thereby enabling retention of the use of existing DMF scores. The CAST index for use in epidemiological surveys is very promising. It should be validated and its reliability and usefulness be tested in different age groups in different countries and cultures.