[A Case of a Bronchial Foreign Body (Artificial Tooth) in the Right Middle Bronchus Without Respiratory Symptoms].

Patients with bronchial foreign bodies often present with subjective symptoms, mainly cough, and removing the foreign bodies is difficult. Bronchial foreign bodies are mostly located in the right lower bronchus, and rarely in the right middle bronchus. An 85-year-old man had no subjective symptoms. He aspirated an artificial tooth during dental treatment the day before visiting our clinic, and consulted his home doctor. He was admitted to our hospital because a chest radiograph indicated the presence of a foreign body in the right middle and lower lung field. Chest computed tomography showed that the bronchial foreign body was located in the right middle bronchus, and it was accompanied by an artifact in the circumference of the lesion, and it seemed to be the metal piece of an artificial tooth. Three-dimensional CT showed the root of the artificial tooth located in center side of the right middle bronchus, and, considering the invasiveness, we decided to remove the tooth by flexible bronchoscopy. The bronchoscopy revealed a metal piece occluding the right middle bronchus without granulation, and we could remove the tooth immediately by grasping the root of the tooth with alligator forceps. We experienced a case of a foreign body located in the right middle bronchus without respiratory symptoms. It is important to carry out image examinations, because elderly patients may not exhibit respiratory symptoms.

Changes in Ridge Dimension with Pontics Immediately Placed at Extraction Sites: A Pilot Study.

The aim of this prospective clinical study was to evaluate dimensional changes following immediate placement of a fixed ovate pontic provisional restoration into an intact extraction socket without grafting. The mean buccolingual dimensional change at 1 month was 0.51 ± 0.48 mm and 0.93 ± 0.55 mm at 3 months. The mean incisoapical dimensional change at 1 month was 0.68 mm ± 0.19 mm, and at 3 months, 1.64 ± 1.35 mm. The dental literature reports dimensional change of 3 to 5 mm in width and 1 to 4 mm in height for ridges with no treatment following extraction. This study provides validation for the use of ovate pontics in the preservation of tissue contour. Further research is needed to determine whether placing a graft into the socket with placement of an ovate pontic will decrease dimensional changes after extraction.

In vitro evaluation of cytotoxicity of different brands of artificial teeth / Avaliação in vitro da citotoxicidade de dentes artificiais de diferentes marcas comerciais

Aim: The present study aimed to evaluate the cytotoxicity of different brands of stock acrylic teeth against fibroblast cells. Materials and Methods: For this experiment, the cell lineage used was the L929 from the American Type Culture Collection (ATCC, Rockville, MD, USA). The brands of stock teeth tested included: Artplus, Biolux, Biotone, Pop Dent, Vipi Dent, Orthosit Ivoclar, Biocler, and Trilux. Each group was placed in contact with the fibroblast cells for the periods of 24, 48, 72, and 168 hours. Control cells, as well asnegative and positive controls, were used to compare the extremes. Results: The results showed cytotoxicity for all the groups tested in the time periods of 24, 48, and 72 hours during the experiment, which occurred in theOrthosit Ivoclar and Trilux groups even after the experiment had been conducted for 168 hours. Conclusion:The researched acrylic teeth developed cytotoxicity against the cells in vitro during the time periods of 24, 48, and 72 hours, while Ivoclar Vivodent and Trilux brands of teeth developed cytotoxicity against the tested cellsduring the time period of 168 hours.

Prosthetic complications in mandibular metal-resin implant-fixed complete dental prostheses: a 5- to 9-year analysis.

PURPOSE: The purpose of this study was to investigate the prosthetic complications of patients with a maxillary complete removable dental prosthesis opposing a mandibular metal-resin implant fixed complete dental prosthesis. MATERIALS AND METHODS: This study is a retrospective analysis of an ongoing prospective study. Dental records from 46 patients treated with a maxillary complete removable dental prosthesis and a mandibular metal-resin implant-fixed complete dental prosthesis were reviewed for 15 different prosthetic complications. The average recall time was 7.9 years. The percentage of patients exhibiting each complication and corresponding 95% confidence intervals was calculated. Logistic regression analysis determined the effect of recall period, age, and gender on each of the following major complications: tooth fracture, complete denture relines, screw complications, and tooth replacement. The recall period was divided into 3 parts: < or = 2 years, 2 to 5 years, and more than 5 years. RESULTS AND CONCLUSION: Statistical significance was exhibited for complete denture relines, posterior tooth replacement, and screw complications. No abutment or framework fractures were recorded for any of the time intervals. The most common complications were prosthetic tooth fracture, tooth wear, maxillary hard relines, and screw complications. Patients were 1.06 times more likely to require a heat-processed hard reline with each year increase of age. After 2 to 5 years and > 5 years, patients were 3.7 times and 8.5 times more likely to require a hard reline than at < or = 2 years. Patients were 52.5 times more likely to need posterior tooth replacement at > 5 years than at < or = 2 years, and 7.7 times more likely to encounter a screw complication at > 5 years than at < or = 2 years.

The ovate pontic design: a histologic observation in humans.

STATEMENT OF THE PROBLEM: Fixed partial dentures with an ovate pontic design contacting the underlying soft tissue may interfere with long-term mucosal health. PURPOSE: The purpose of this study was to examine the clinical and histologic characteristics of the human alveolar ridge mucosa adjacent to an ovate pontic-designed restoration. MATERIAL AND METHODS: Twelve patients requiring maxillary fixed partial dentures (either implant- or tooth-supported) with a pontic site in the premolar or molar region were studied. The pontics had an ovate design and were adapted to the underlying mucosa with tight but noncompressive contact. Patients used Super Floss once a day to clean the infrapontic area. After 12 months, soft tissue biopsy specimens about 3 x 3 mm in size were obtained (1) from the ridge mucosa in contact with the pontic (test site) and (2) from an adjacent uncovered masticatory mucosal area (control site). Histometrically, the thickness of the epithelium and the keratin layer and the height of the connective tissue papillae were measured. Morphometrically, the composition of the connective tissue of the specimens was analyzed in a 200-microm-wide zone immediately subjacent to the epithelium (zone A) and in a 200-microm-wide central connective tissue portion (zone B). A point-counting procedure was used to calculate the relative proportions occupied by collagen, fibroblasts, vascular structures, inflammatory cells, and residual tissue. Differences between the tissue fractions in test and control sites were analyzed with the Wilcoxon signed rank test (.05 level of significance). RESULTS: At 12 months, only 3 pontic sites showed clinical signs of mild inflammation, whereas the other test sites and all control sites appeared healthy. A thinner keratin layer was observed in pontic sites than in control sites (8 microm vs 22 microm). Larger tissue fractions of inflammatory cells were found in pontic sites than in control areas in the zone immediately subjacent to the epithelium. CONCLUSION: Within the limitations of this study, restoring an edentulous space with an ovate pontic supported by adequate oral hygiene measures was not associated with overt clinical signs of inflammation. Histologically, however, this pontic design was associated with a thinner keratin layer and with changes in the composition of the connective tissue compartment subjacent to the epithelium.

Complications and failures in removable partial dentures: a clinical evaluation.

The design of removable partial dentures (RPDs) is an important factor for good prognostication. The purpose of this study was to clarify the effectiveness of denture designs and to clarify the component that had high rates of failure and complications. A total of 91 RPDs, worn by 65 patients for 2-10 years, were assessed. Removable partial dentures were classified into four groups: telescopic dentures (TDs), ordinary clasp dentures (ODs), modified clasp dentures (MDs) and combination dentures (CDs). The failure rates of abutment teeth were the highest and those of retainers were the second highest. The failure rates of connectors were generally low, but they increased suddenly after 6 years. Complication and failure rates of denture bases and artificial teeth were generally low. Complication and failure rates of TDs were high at abutment teeth and low level at retainers. Complication and failure rates of ODs were high at retainers.

Effect of artificial tooth material on mandibular residual ridge resorption.

PURPOSE: In this 10-year longitudinal study we evaluated the amount of mandibular residual ridge resorption for 2 groups of subjects with complete dentures, one group with porcelain artificial teeth and the other with acrylic resin teeth. METHODS: One hundred and nine patients who had undergone ridge extension procedures with skin graft and prosthetic rehabilitation with porcelain or acrylic resin teeth were investigated for mandibular bone loss. Measurements were made on serial cephalograms. RESULTS: There were no significant differences between the groups in terms of their baseline characteristics (age, period of edentulousness, period of observation, vertical facial morphology, sex, severity of atrophy or presence of bruxism). Similarly, there were no statistically significant differences in amount of bone loss in relation to baseline characteristics. CONCLUSION: The view that acrylic resin teeth should be preferred to prevent bone resorption of the mandibular residual ridge is not supported by these data. Further research concerning soft denture-lining material should be undertaken to elucidate the potential role of denture pressure in ridge resorption.

Resistência de união entre dentes artificiais e bases de próteses polimerizadas com microondas / Strength of bonding between artificial teeth and acrylic resins for denture base

A ruptura entre dentes de resina acrílica e sua base de prótese é um problema de grande freqüência na maioria dos laboratórios, e causa desconforto nos pacientes. Tendo em vista que a causa específica da falha desta união ainda não foi determinada, o objetivo do presente trabalho é comparar a retenção de dentes de resina acrílica com as resinas Lucitone 550 e Acron MC, segundo diferentes métodos de polimerização. Foram confeccionados 18 corpos-de-prova de acordo com a especificação número 15 da A.D.A., sendo sete em resina Lucitone 550, polimerizada em banho de água aquecida por 3 horas (Técnica modificada de Tuckfield); e 07 em resina Acron MC polimerizada em forno de microondas à 900 W durante 03 minutos. Em uma das extremidades dos corpos-de-prova foi prensado um dente de resina acrílica (Biotone, Dentsply). Os testes de tração foram realizados em Máquina de Ensaio Universal (Instron) com velocidade de 0,5mm/min. Os resultados indicaram que a força (Kg) média necessária para provocar a falha entre os dentes e a resina Lucitone 550 foi de 66,58 (± 19,93) e entre os dentes e a resina Acron MC foi de 51,73 (± 11,91); valores estes que submetidos ao teste t de Student para amostras pareadas não apresentaram diferenças significantes. Diante dos resultados, pode-se concluir que o método de polimerização não influenciou a resistência de união entre dentes artificiais e resina acrílica para base de prótese, no entanto as técnicas para realização deste tipo de teste devem ser reavaliadas

Occlusion and restorative materials.

Undoubtedly, the materials used in conjunction with restorative dentistry have been changing over the years. Although restorative systems before the early 1960s have changed only moderately, the last two to three decades have witnessed some fairly dramatic developments. Composite resins, mercury-free alloys, quartz-free ceramics, and gold-reduced or gold-free alloys represent some of the more obvious introductions. Considerable information has been made available concerning their physical and mechanical characteristics; however, little has been published concerning their effect on occlusion and equilibration of the teeth.