Pathohistology of undecalcified primary teeth in vitamin D-resistant rickets: review and report of two cases

The basic dental defects in vitamin D-resistant rickets seem to be manifested in dentin. Enamel is usually reported to be normal. This histologic examination showed the penetration of microorganisms through the calcified structures of the enamel layer without visible caries. The microorganisms passed through the dentinoenamel junction and invaded dentin, which was characterized by calcospherites and large amounts of interglobular dentin. Furthermore, microorganisms could be detected in dentinal tubules, which were exposed to the oral cavity when enamel was removed. However, large areas of tertiary dentin extended between such tubules and the pulp. These light microscopic results suggest that clinical manifestations, such as, pulp recrosis and periapical lesions (without carious defects) may be caused by the penetration of microorganisms through microclefts of the enamel layer as well as pathologically altered enamel microstructures of affected teeth.

Case-control study of non-carious cervical lesions

An exploratory case-control study of non-carious cervical lesions was undertaken to examine the effects of a variety of risk factors. Candidate exposure variables were related to erosion, abrasion, and tooth flexure, the three principal putative causal mechanisms for cervical lesions. Because previous studies have tended to focus on specific causal mechanisms, evidence for a multifactorial etiology is inconclusive. Data describing exposure factors were obtained through clinical examination, dietary and behavioral questionnaires, and analysis of study casts from 264 subjects (137 cases, 127 control). Salivary data were also obtained for a subset of these subjects. Patient and tooth-level logistic regression models were constructed for the full subject group, and the subset with salivary data. For the two patient-level models, only exposures related to brushing entered. For tooth-level models, multiple exposures representing all three causal mechanisms were included in both models. The results suggest that non-carious cervical lesions do have a multifactorial etiology, and that multiple causal mechanisms may operate in the initiation and progression of individual lesions.

Dental erosion. Definition, classification and links

An overview of tooth wear, i.e. of non-carious destructive processes affecting the teeth including abrasion, demastication, attrition, abfraction, resorption and erosion is presented. The nomenclature and classification of dental erosion commonly used in the dental literature are summarized. They are based on etiology (extrinsic, intrinsic, idiopathic), on clinical severity (Classes I to III), on pathogenetic activity (manifest, latent) or on localization (perimolysis). Interactions between erosion and abrasion, demastication, attrition, and abfraction as well as caries and low salivary flow rate are highlighted.

Clinical assessment of periodontitis in young adults--evaluation of probing depth and partial recording methods

The present study was carried out to compare the ability of different methods of periodontal assessment to identify those subjects in a population who had suffered the worst periodontal breakdown. Comparisons were made between full mouth approximal attachment loss (CAL) assessment and methods relying on pocket probing depth (PPD) evaluation or on partial recording of CAL or PPD. Both of the latter types of assessment are commonly used in epidemiological surveys. 202 workers at an electronics factory aged between 20 and 40 yr were examined for approximal PPD and CAL, excluding third molars. The data were used to determine which individuals had the worst periodontitis based on CAL at several thresholds. Further analysis was carried out to determine which of these subjects would have been identified on the basis of the presence of deep (> or = 6 mm) pocketing, or by using one of a battery of partial recording subsets. CAL was frequently present in the absence of deep pocketing. A subset made up of four approximal sites around each of the 10 index teeth recommended by the WHO for partial recording (two molars in each quadrant and maxillary right and mandibular left central incisors) and a subset comprising maxillary buccal and mandibular lingual sites ("Pritchard" sites) performed best of the subsets considered in identifying the subjects who had been found by full mouth assessment to have at least one or at least two approximal sites with CAL at thresholds of 2, 3 or 4 mm. It was concluded that measurements of CAL using either of these subsets should reduce problems of under-recording of the prevalence of periodontitis associated with the use of PPDs alone or on CAL assessment at other partial recording subsets.

Non-carious cervical tooth loss: Part 1

Non-carious cervical tooth loss is not always attributable to a single causative factor, as evidenced by the numerous terminologies used. In this, the first of two articles, the aetiology and prevalence of non-carious tooth loss are discussed. Guidelines are suggested as to how it may be diagnosed, prevented and monitored. A further article will cover the restorative management.

Adaptability and microleakage of indirect resin inlays: an in vivo investigation

The purpose of this in vivo study was to evaluate the microleakage of indirect composite resin inlays and to determine the thickness of composite resin luting material. Twenty periodontally involved posterior teeth scheduled for extraction were selected and Class II cavities were prepared. Ten cavities had gingival margins placed in enamel above the cementoenamel junction, and the other 10 were placed in dentin below the cementoenamel junction. Six months after cementation, the teeth were extracted and analyzed. The leakage was higher in inlays with gingival margins in dentin than in inlays with gingival margins in enamel. The cement thickness was between 15 and 40 microm, a clinically acceptable range.