Sites of dental erosion are saliva-dependent

Acid demineralization of teeth causes occlusal erosion and attrition and associated non-carious cervical lesions at sites relatively unprotected by saliva. Associations of occlusal pathology and cervical lesions were looked for in 450 patients with toothwear, and 174 subjects with cervical lesions were identified. Associations of occlusal attrition, or erosion, or no wear, with cervical lesions at 72 buccal and lingual sites were recorded from epoxy resin replicas of the subjects' dentitions (3241 teeth). Criteria used to discriminate occlusal erosion from attrition; and shallow from grooved and wedge-shaped cervical lesions were delineated by scanning electron microscopy (SEM). In the absence of occlusal pathology, cervical lesions were very rare (

Occupational therapists' use and perceptions of written client education materials

OBJECTIVE. The purpose of this study was to examine occupational therapists' use and perceptions of written education materials for clients and the factors that therapists consider before distributing written materials to clients This study also aimed to determine whether use and perceptions of these materials differed for older clients METHOD. A random sample of 50 occupational therapists from Queensland, Australia, working in adult physical disabilities settings was surveyed with a structured questionnaire Data were analyzed descriptively and with nonparametric statistics RESULTS. Of 49 participants who used written materials, 54% had given them to more than halt of their last 10 clients, regardless of the clients' age Written materials, most often information sheets developed by the participants themselves; handwritten notes; and pamphlets were principally used to reinforce verbal information. Clients' cognitive abilities, primary language, communication skills, vision, and level of education most often were considered before distributing written materials Although participants generally were positive about the content and effectiveness of materials, ratings were significantly less positive related to older clients CONCLUSION. Client education was a core treatment modality for participants in this study, with written media most commonly being used to supplement verbal education Because participants were least positive about the effectiveness of written materials for older clients, further development of materials for this audience may be indicated.

Predicting discharge outcomes for stroke patients in Australia

Objective: This study aimed to describe discharge outcomes and explore their correlates for patients rehabilitated after stroke at an Australian hospital from 1993 to 1998. Design: Data on length of stay, discharge functional status, and discharge destination were retrospectively obtained from medical records. Patients' actual rehabilitation length of stay was compared with the Australian National Sub-Acute and Non-Acute Patient predicted length of stay. The change in length of stay over the 5-yr period from 1993 to 1998 was documented. Results: Patients' mean converted motor FIMTM scores improved from 53.1 at admission to 74.1 at discharge. Lower admission-converted motor FIM scores were related to longer length of stay, lower discharge-converted motor FIM scores, and the need for a change in living situation on discharge. Conclusion: The results of this study provide Australian data on discharge outcomes after stroke to assist in the planning and delivery of appropriate interventions to individual patients during rehabilitation.

Dental erosion in asthma: A case-control study from south east Queensland

Background: Asthma medication places patients at risk of dental erosion by reducing salivary protection against extrinsic or intrinsic acids. But patterns of lesions in asthmatics may differ from patterns in non-asthmatics, because gastro-oesophageal reflux (GOR) is found in 60 per cent of asthmatics. Methods: The lesions in 44 asthma cases were compared to those of age and sex match controls with no history of asthma or medications drawn from the dental records of 423 patients referred concerning excessive tooth wear. The subjects were 70 males age range 15 to 55 years and 18 females age range 18 to 45. Anamnestic clinical data were compared between the two groups. Models of all 88 subjects were examined by light microscopy, and wear patterns were recorded on permanent central incisor, canine, premolar and first molar teeth. Results: Clinical differences were a higher incidence of tooth hypersensitivity; xerostomia, salivary gland abnormalities, gastric complaints, and self induced vomiting in the cases. No differences were found between the cases and controls on citrus fruit and acid soft drink consumption. More occlusal erosion sites were found in cases, whereas more attrition sites were found in the controls. There were no significant differences in palatal erosion on maxillary anterior teeth found between cases and controls. Lingual erosion of the mandibular incisors, found only in GOR patients, was not observed. Conclusions: A higher incidence of erosion was found in asthmatics. Gastro-oesophageal reflux symptoms were not associated with the sign of lingual mandibular incisor erosion. The clinical significance is that asthmatics are at risk of dental erosion from extrinsic acid, but GOR does not appear to contribute in a site-specific manner.

Shear stress and sediment transport calculations for sheet flow under waves

A simple method is provided for calculating transport rates of not too fine (d(50) greater than or equal to 0.20 mm) sand under sheet flow conditions. The method consists of a Meyer-Peter-type transport formula operating on a time-varying Shields parameter, which accounts for both acceleration-asymmetry and boundary layer streaming. While velocity moment formulae, e.g.., = Constant x calibrated against U-tube measurements, fail spectacularly under some real waves (Ribberink, J.S., Dohmen-Janssen, C.M., Hanes, D.M., McLean, S.R., Vincent, C., 2000. Near-bed sand transport mechanisms under waves. Proc. 27th Int. Conf. Coastal Engineering, Sydney, ASCE, New York, pp. 3263-3276, Fig. 12), the new method predicts the real wave observations equally well. The reason that the velocity moment formulae fail under these waves is partly the presence of boundary layer streaming and partly the saw-tooth asymmetry, i.e., the front of the waves being steeper than the back. Waves with saw-tooth asymmetry may generate a net landward sediment transport even if = 0, because of the more abrupt acceleration under the steep front. More abrupt accelerations are associated with thinner boundary layers and greater pressure gradients for a given velocity magnitude. The two real wave effects are incorporated in a model of the form Q(s)(t) = Q(s)[theta(t)] rather than Q(S)(t) = Q(S)[u(infinity)(t)], i.e., by expressing the transport rate in terms of an instantaneous Shields parameter rather than in terms of the free stream velocity, and accounting for both streaming and accelerations in the 0(t) calculations. The instantaneous friction velocities u(*)(t) and subsequently theta(t) are calculated as follows. Firstly, a linear filter incorporating the grain roughness friction factor f(2.5) and a phase angle phi(tau) is applied to u(infinity)(t). This delivers u(*)(t) which is used to calculate an instantaneous grain roughness Shields parameter theta(2.5)(t). Secondly, a constant bed shear stress is added which corresponds to the streaming related bed shear stress -rho ($) over bar((u) over tilde(w) over tilde)(infinity) . The method can be applied to any u(infinity)(t) time series, but further experimental validation is recommended before application to conditions that differ strongly from the ones considered below. The method is not recommended for rippled beds or for sheet flow with typical prototype wave periods and d(50) < 0.20 turn. In such scenarios, time lags related to vertical sediment movement become important, and these are not considered by the present model. (C) 2002 Elsevier Science B.V. All rights reserved.

Chronic draining mandibular fistula in a Californian Sea Lion

A male Californian Sea Lion with a chronic draining mandibular fistula had failed to respond to conventional treatments. This was effectively treated by endodontic therapy utilising calcium hydroxide to seal the apex and glass ionomer cement to obturate the root canal of the canine tooth.

Comparisons between bone and cementum compositions and the possible basis for their layered appearances

In humans, age estimation from the adult skeleton represents an attempt to determine chronological age based on growth and maturational events. In teeth, such events can be characterized by appositional growth layers in midroot cementum. The purpose of this study was to determine the underlying cause of the layered microstructure of human midroot cementum. Whether cementum growth layers are caused by changes in relative mineralization, collagen packing and/or orientation, or by variations in organic matrix apposition was investigated by subjecting midroot sections of human canine teeth to analysis using polarized light and scanning electron microscopy (SEM). Polarized light was used to examine transverse midroot sections in both mineralized and demineralized states. Mineralized sections were also reexamined following subsequent decollagenization. Polarized light was additionally used in the examination of mineralized sections taken transversely, longitudinally, and obliquely from the same tooth root. From the birefringence patterns it was concluded that collagen orientation does not change with varying section plane. Instead, the mineral phase was most responsible for the birefringence of the cementum. SEM studies suggested that neither collagen packing nor collagen orientation change across the width of the cementum, confirming and validating the results of the polarized light examination. Also, SEM analysis using electron backscatter and the electron probe suggested no changes in the mean atomic number density, calcium, phosphate, and sulfur levels across the width of the cementum. Therefore, we conclude that crystalline orientation and/or size is responsible for the layered appearance of cementum. (Bone 30:386-392; 2002) (C) 2002 by Elsevier Science Inc. All rights reserved.

Identification of the enamelin (g.8344delG) mutation in a new kindred and presentation of a standardized ENAM nomenclature

The amelogenesis imperfectas (Al) area geneticatly heterogeneous group of diseases that result in defective development of tooth enamel. Although X-linked, autosomal. dominant and autosomal. recessive forms of Al have been clinically characterized, only two genes (AMELX and ENAM) have been associated with Al. To date, three enamelin (ENAM) mutations have been identified. These mutations cause phenotypically diverse forms of autosomal. dominant Al. Detailed phenotype-genotype correlations have not been performed for autosomal. dominant Al due to ENAM mutations. We identified a previously unreported kindred segregating for the ENAM mutation, g.8344delG. Light and electron microscopy analyses of unerupted permanent teeth show the enamel is markedly reduced in thickness, Lacks a prismatic structure and has a laminated appearance. Taken together these histological features support the enamelin protein as being critical for the development of a normal. enamel. thickness and that it Likely has a role in regulating c-axis crystallite growth. Because there is growing molecular and phenotypic diversity in the enamelin defects, it is critical to have a nomenclature and numbering system for characterizing these conditions. We present a standardized nomenclature for ENAM mutations that will allow consistent reporting and communication. (C) 2003 Elsevier Science Ltd. All rights reserved.

Diagnosis and management of unusual dental abscesses in children

Although the majority of dental abscesses in children originate from dental caries or trauma, a few are associated with unusual conditions which challenge diagnosis and management. Recent research findings have shed light on these unusual entities and greatly improved understanding of their clinical implications. These conditions include developmental abnormalities such as dens invaginatus in which there is an invagination of dental tissues into the pulp chamber and dens evaginatus in which a tubercle containing pulp is found on the external surface of a tooth crown. In addition, inherited conditions which show abnormal dentine such as dentine dysplasia, dentinogenesis imperfecta, and osteogenesis imperfecta predispose the dentition to abscess formation. Furthermore, 'spontaneous' dental abscesses are frequently encountered in familial hypophosphataemia, also known as vitamin D-resistant rickets, in which there is hypomineralization of dentine and enlargement of the pulp. In addition to developmental conditions, there are also acquired conditions which may cause unusual dental abscesses,. These include pre-eruptive intracoronal resorption which was previously known as 'pre-eruptive caries' or the 'fluoride bomb'. In addition, some undiagnosed infections associated with developing teeth are now thought to be the mandibular infected buccal cysts which originate from infection of the developing dental follicles. In the present paper, these relatively unknown entities Which cause unusual abscesses in children are reviewed with the aim of updating the general practitioner in their diagnosis and management.

Endodontic sequelae of dental erosion

Background. The incidence of, pulp involvement in patients with excessive wear has not been extensively documented. Methods: Clinical, records of 448 patients with excessive tooth wear were reviewed and 52 cases (11.6 per cent) with near or frank pulp exposures or root canal treatments were found and their numbers and sites were tabulated. Light microscopy of study models was used to determine aetiology at each site of exposure as. attrition, erosion or abrasion, scanning electron microscopy (SEM) was performed on some individual teeth. Results: Forty sites of near exposure and 57 sites of frank exposures or root canal treatments were found, some cases had both types of exposure. The commonest sites exposed by erosion were the palatal surfaces of maxillary, and the incisal surfaces of mandibular anterior teeth. Posterior teeth were not commonly affected. Toothbrush abrasion had exacerbated softie lesions as shown by SEM. Conclusions: Endodontic sequelae were found in 11 per cent of tooth wear patients as late stages of dental erosion. Near and frank exposures of the pulp thus constitute a small but significant, problem for,the Australian dental profession's concern in the of the tooth wear cases.

The current status of laser applications in dentistry

A range of lasers. is now available for use in dentistry. This paper summarizes key current and emerging applications, for lasers in clinical practice. A major diagnostic application of low power lasers is the detection of caries, using fluorescence elicited from hydroxyapatite or from bacterial by-products. Laser fluorescence is an effective method for detecting and quantifying incipient occlusal and cervical,carious lesions, and with further refinement could be used in the, same manner for proximal lesions. Photoactivated dye techniques have been developed which use low power lasers to elicit a photochemical reaction, Photoactivated dye techniques' can be used to disinfect root canals, periodontal pockets, cavity preparations and sites of peri-implantitis. Using similar principles, more powerful lasers tan be used for photodynamic therapy in the treatment of malignancies of the oral mucosa. Laser-driven photochemical reactions can also be used for tooth whitening. In combination with fluoride, laser irradiation can improve the resistance of tooth structure to demineralization, and this application is of particular benefit for susceptible sites in high caries risk patients. Laser technology for caries' removal, cavity preparation and soft tissue surgery is at a high state of refinement, having had several decades of development up to the present time. Used in conjunction with or as a replacement for traditional methods, it is expected that specific laser technologies will become an essential component of contemporary dental practice over the next decade.

Perceptions of evidence-based practice: A survey of Australian occupational therapists

Evidence-based practice (EBP) requires clinicians to access, appraise and integrate research literature with clinical experience and clients' perspectives. Currently, little is known about occupational therapists' attitudes to EBP, their perception of implementation barriers or their educational needs. A questionnaire reflecting these issues was sent to a proportionate random sample of 1491 members of the national professional occupational therapy association, OT AUSTRALIA. The questionnaire was completed by 649 (44%) participants. Occupational therapists were positive about EBP with most (96%) agreeing that EBP is important to occupational therapy. Although 56% used research to make clinical decisions, more relied on clinical experience (96%), information from continuing education (82%) and colleagues (80%). Lack of time, evidence and skills were identified as the main barriers to the implementation of EBP. Over half (52%) expressed strong interest in EBP skills training, and most (80%) indicated an interest in the availability of brief summaries of evidence. Targeted educational initiatives, resources and systems are needed to support EBP in occupational therapy.