A 2-year follow-up study of titanium crowns

In 1986, 149 patients were provided with titanium crowns. The method used for fabrication of the titanium copings involved two principles: machine duplication of models and electric discharge machining. For the veneering of the copings, Isosit was used for the first 90% of the crowns in the series, and the Dentacolor-Silicoater technique for the last 10%. Of 205 individual crowns cemented in 1986, 167 could be examined after 2 years. The crowns were rated by four independent examiners using the CDA quality evaluation system. Bleeding Index and Margin Index were also used. The Margin Integrity score was recorded as satisfactory for all crowns examined over the period studied. A vast majority of the margins were rated as excellent. Isosit (n = 145) disclosed shortcomings including fractures and substantial deteriorations of Surface and Color and of Anatomic Form. With Dentacolor as veneering material (n = 18) the results with the factors Surface and Color and Anatomic Form were still rated satisfactory after 2 years, and no fractures of the veneering material were registered. Bleeding Index and Margin Index showed comparatively small changes after 2 years.     

A case of benign cementoblastoma

A rare case of benign cementoblastoma is reported. Active cementoblasts adding cementoid tissue were observed histologically by means of specific staining for unmineralized matrix of hard tissue. A polarizing microscope and an x-ray diffractometer were used to clarify the cementum-like tissue of benign cementoblastoma. The collagen bundles of tumor tissue showed irregular and random arrangements under polarized light. The qualitative analysis revealed that the mineralized component was composed of low-crystalline hydroxylapatite.     

Effect of moisture and aging on gutta-percha.

The purpose of this article was to study the plasticizing effect of controlled levels of different humidities on native and commercial gutta-percha samples. It was expected that the results might provide the practicing endodontist with invaluable insight into the mechanical properties of commercial gutta-percha cones (i.e. retrievability, malleability, flexibility, torsional, and bending ability). The "conditioning" of the gutta-percha samples depended greatly on the percentage of compatible and incompatible substances. Mixtures of native gutta-percha with compatible substances (e.g. wax) showed greater elongation, tensile strength, and number of rotations but lower deformation angle than mixtures of native gutta-percha with incompatible substances (e.g. salts, metal oxides). The observed lower values for tensile strength and torsional strain and higher value for elongation and number of rotations for wet samples compared with the dry ones were attributed to the plasticizing effect on gutta-percha of the insertions of water molecules in the polymer chains.     

Cause of death in squamous cell carcinoma of the head and neck. An autopsy study on 31 patients.

A series of 31 autopsied patients, with a history of head and neck squamous cell carcinoma is reported, with the emphasis on the cause of death. There were 26 males and 5 females; mean age being 64 years (range 44-88 years). Locoregional disease (LRD) was the cause of death in 19 patients (61%) and was present in 2 patients dying of an unrelated cause. Distant metastasis (DM) was found in 8 patients (26%) but had caused death in only 1 of them. A shorter survival time for patients with DM than for those without (8 months versus 13 months) indicates that DM is established early in the course of the disease. Therefore, a longer survival time will not result in an increase in DM and we infer that a better locoregional control will also not result in a real increase in DM but only in an apparent one, due to a shift of cause of death from LRD to DM in a group of patients that formerly would have died of LRD before the already present DM had become manifest.     

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 5. General discussion and conclusions.

Part 5 is the final part of a series of five articles reporting on an international, multicenter clinical audit of treatment outcome for complete UCLP. A number of recommendations for the methodology of future studies is made especially with respect to entry criteria, sample size, assumptions of homogeneity, and the reproducibility and validity of outcome measures. The findings of the present study regarding clinical procedures are presented tentatively, and improvement and extension of the methodology are required. It appears, however, that acceptable results can be achieved by different programs and ultimately clinical choices may be based on factors such as complexity, costs, and demands of treatment. Standardization, centralization, and the participation of high volume operators were associated with good outcomes, and nonstandardization and the participation of low volume operators with poor outcomes. Therapeutic factors associated with good outcomes were the employment of a vomer flap to close the anterior palate, and poor outcomes with primary bone grafting and with active presurgical orthopedics.     

The oral health and attitudes to dental treatment of a dentate elderly population in Mosgiel, Dunedin.

As part of the Mosgiel Community Study, a longitudinal investigation of the health of the elderly, a dental survey was used to determine the oral health status and treatment needs, both objective and subjective, of a group of dentate older adults. Sixteen percent of the 817 subjects were dentate. Of these, 95 were available for the dental survey, and they were questioned and examined at their homes. The mean age was 77 years, and 55 percent of subjects were male; disproportionately more older males than females had retained some of their natural teeth. Seventy-two percent regularly sought dental treatment, and 39 percent felt they were in need of treatment. Few real barriers to treatment were identified, although a major obstacle preventing many from seeking treatment was their lack of perceived need. However, even the realisation that they required treatment was not sufficient cause for many to seek treatment. All subjects required some form of dental treatment. Eighty-five of the 95 subjects required at least one restoration, and 16 percent advanced restorative treatment. The frequencies of coronal and root surface caries were similar. Oral mucosal pathology was also common. Sixty-five percent of denture wearers required prosthetic treatment. Most subjects needed simple periodontal treatment, but 11 percent required advanced therapy. The main oral health problems of this group related to the simple management of plaque-related disease, and the wearing of dentures. However, 24 percent of people required complex restorative and periodontal treatment, or both.     

Reliability of a facebow transfer procedure.

The three-dimensional orientation of a maxillary cast mounting from a simulated-kinematic facebow transfer was evaluated in multiple trials among three operators on a single subject. The anterior and posterior anatomic facial reference points were marked on the subject. Each operator performed a separate series of trials to reset the anterior facebow component, the two posterior facebow components, and a control series with no resetting of any facebow components relative to the subject. The x, y, and z coordinates of three reference points on the maxillary cast were determined with a machinist microscope relative to a fixed reference after each facebow transfer. A range of differences between mountings of the maxillary cast were found between trials with all three methods used. These mounting errors were due to setting of the instrument and would be expected in routine clinical use of this instrument.