Fit of three porcelain-fused-to-metal marginal designs in vivo: a scanning electron microscope study

This study examined the comparative fit in vivo of three types of PFM crown margins. Marginal openings were measured with an SEM on replicas derived from elastomeric impressions. There was no significant difference among beveled metal margins, metal butt margins, or porcelain butt margins either before or after cementation at the 95% confidence level. This study has shown that it is possible under clinical conditions to consistently produce porcelain butt margins with less than 50 micron marginal opening in PFM restorations.

The significance of the mouth in old age

Information on the significance of the mouth in old age has been obtained from structured interviews with older subjects focused largely on the significance and impact of oral dysfunction. There is, however, a growing sense that inventories of dysfunction do not explain the full significance of aging and that structured interviews offer little opportunity to explore feelings and concerns. This study adopted a qualitative approach to collect and analyse data from unrestricted responses to the question: "What is the significance of oral health in the lives of older adults?" The data were collected by interviewing 24 elders, and major themes in transcripts of the interviews were identified by the research team using inductive analytical techniques. Our findings indicate that the significance of oral health in this age group was considered largely within the context of three interacting themes--comfort, hygiene and health--that can be illustrated within a theoretical framework that corresponds with more general theories of aging to offer guidance for health promotion and further research. Overall, the participants offered a positive perspective on the mouth, and they emphasized the need to adapt as an integral part of successful aging and a means of coping with the impact of oral disorders.

Problems with prostheses on implants: a retrospective study

Prosthetic parameters for implant success have not been well defined but should include patient satisfaction and prosthesis maintenance, including adjustments and repairs. In addition, differences between fixed and removable implant-supported prostheses (ISPs) should be quantified. This study retrospectively evaluated both patient satisfaction and maintenance for 156 patients. Removable ISPs averaged almost three times as many adjustments per prosthesis (2.1 versus 0.8 per fixed ISP) and more than twice as many repairs (1.9 per removable ISP versus 0.9 per fixed ISP). The most common adjustments were to the contour of both types of prosthesis, and the most frequent repairs involved the retentive clips with removable ISPs and the gold screws with fixed ISPs. The incidence of repeat repairs was more than twice as high with removable prostheses compared with fixed prostheses. However, the repairs to opposing dentures most often needed were for conventional dentures opposing fixed ISPs. The vast majority of repairs were needed within the first year of service. Despite the high maintenance needed, patients were satisfied with both types of ISP, with the exception of limited satisfaction with cleansability, particularly with fixed restorations. The high incidence of early repairs, and the greater potential for a removable ISP requiring adjustment and repair, should be considered both when discussing options with the patient and when estimating treatment and maintenance costs before the commencement of implant therapy.

Conflicting priorities: oral health in long-term care

Open-ended interviews were conducted with 109 individuals. These included: administrators, staff, dental personnel, residents, and family members, associated with 12 long-term-care (LTC) facilities to contrast different human resource and organizational strategies for managing the delivery of oral health care to the elderly residents. A multiple case-study analysis revealed that no particular organizational strategy was ideal, although three important components--oral hygiene, diagnostic assessments, and dental treatment--were common to all. The dental personnel everywhere believed that oral health in the midst of other conflicting priorities received inadequate attention, while the administrators and staff acknowledged that they were weak at recognizing oral disorders and assisting with oral hygiene. In all, the interviews offered a portrait of the conflicting priorities associated with LTC, and they provide practical insights to successful strategies of care in this population.

Provision of mouth-care in long-term care facilities: an educational trial

OBJECTIVES

This randomized clinical trial aimed to assess the effectiveness of a pyramid-based education for improving the oral health of elders in long-term care (LTC) facilities.

METHODS

Fourteen facilities matched for size were assigned randomly to an active or control group. At baseline in each facility, care-aides in the active group participated with a full-time nurse educator in a seminar about oral health care, and had unlimited access to the educator for oral health-related advice throughout the 3-month trial. Care-aides in the control group participated in a similar seminar with a dental hygienist but they received no additional advice. The residents in the facilities at baseline and after 3 months were examined clinically to measure their oral hygiene, gingival health, masticatory potential, Body Mass Index and Malnutrition Indicator Score, and asked to report on chewing difficulties.

RESULTS

Clinical measures after 3 months were not significantly different from baseline in either group, indicating that education neither influenced the oral health nor the dental hygiene of the residents.

CONCLUSIONS

A pyramid-based educational scheme with nurses and care-aides did not improve the oral health of frail elders in this urban sample of LTC facilities.

Novel fracture toughness test using a notchless triangular prism (NTP) specimen

The aim of this study was to develop and validate a new method for determining the fracture toughness of materials and adhesive interfaces. The new test specimen is a notchless triangular prism (NTP) which, when placed in the testing holder, achieves a configuration similar to that of the standard chevron-notched short rod (CNSR) specimen. It can be cast, ground, or simply machined easily and reproducibly without cutting an initial notch. Finite element analysis of a modeled NTP specimen loaded in tension showed a stress distribution similar to a CNSR specimen. A very good correlation was obtained between the NTP and CNSR fracture toughness values of poly(methyl methacrylate) during a calibration study. Fracture toughness values similar to those reported in the literature were obtained for several dental materials and one adhesive interface using the NTP test. The fracture patterns were indicative of plane strain conditions during testing. All bulk specimens and most of the adhesive specimens showed crack arrest, which suggested a stable, well-controlled testing procedure. These results suggest that the NTP fracture toughness test can be used to determine the fracture mechanics of bulk materials and adhesive interfaces.

Oral health in a long-term care institution equipped with a dental service

The oral health and medico-dental status of 250 mostly elderly residents of a long term care institution were assessed by examination and a review of medical records. In addition, attitudes to dental care, dental experiences, and demands for care were solicited from those who could participate in an interview. There were no dental complaints from 70% of those interviewed. The complaints most frequently reported were difficulties with mouth dryness, hygiene, and chewing. Natural teeth remained in at least one jaw in 30% of the 245 residents examined. Dental caries was present in 78% of this dentate group, with coronal and root lesions equally prevalent. Gingival bleeding was also common in this group and 29% had deep periodontal pockets. Nearly 50% of the mandibular dentures and 25% of the maxillary dentures examined were inadequate. Mandibular dysfunction occurred in 25% of the population and was more frequent in the dentate group. Oral mucosal pathoses were rare. No correlation was found between the systemic health and the oral health of the residents. There was a need to improve the oral hygiene of most of those examined. Less than 20% of the denture wearers would have benefitted from treatment and 10% of those with defective dentures were considered unsuitable for treatment. In contrast, 60% of those with natural teeth required restorations and 36% needed one or more teeth removed. Very few urgent needs were seen. An inter-examiner accumulative inconsistency of 11% was measured between the three examiners, and a third of the assessments made of periodontal status were contradictory.

Age, gender, dentures and oral mucosal disorders

The numbers of participants over 75 years of age in previous studies of oral health have not been sufficient to permit a full investigation of the influence of age on the mouth. In this study a disproportionate stratified random sample of 255 independent elders was selected from a list of urban voters to provide similar numbers of men and women in three age groups. The subjects were interviewed and examined, and nearly half of them had mucosal disorders. There was a significant (P < 0.05) association between mucosal lesions and the use of dentures and tobacco, whereas stomatitis, denture-related hyperplasia and angular cheilitis in particular were associated significantly with men and with the use of defective dentures. Logistic regression revealed that neither age alone nor the quality of dentures predispose to mucosal lesions, but that the odds of finding stomatitis, denture-related hyperplasia and angular cheilitis in particular increased about three-fold in denture-users, and almost doubled in men.

The concept of validity in sociodental indicators and oral health-related quality-of-life measures

BACKGROUND

Most of the psychometric instruments used to measure quality of life associated with oral impairment and disability from the perspectives of older adults focus on negative experiences, and pay little attention to the possibility of positive reactions to disablement. This oversight challenges the validity of the instruments in current use, and raises questions about the process used to validate them.

OBJECTIVES

In this study, we consider the general attributes of psychometric validity, and how they have been applied to oral health-related instruments.

CONCLUSIONS AND RECOMMENDATIONS

The psychometric characteristics and predictive validity of existing dental instruments are still weak, probably because the instruments fail to address the broad range of personal variables that influence oral health, disability and quality of life. We recommend, therefore, that a continuous process of validation be adopted to include: (1) assessments of the theoretical framework supporting the instruments; (2) evaluations of the focus and structure of the questions used; and (3) enhancements of the prediction value of instruments applicable to oral health-related beliefs and behaviours.

Assessment of periodontal conditions and systemic disease in older subjects. I. Focus on osteoporosis

BACKGROUND

Osteoporosis (OPOR) is a common chronic disease, especially in older women. Patients are often unaware of the condition until they experience bone fractures. Studies have suggested that OPOR and periodontitis are associated diseases and exaggerated by cytokine activity. Panoramic radiography (PMX) allows studies of mandibular cortical index (MCI), which is potentially diagnostic for OPOR.

AIMS

i). To study the prevalence of self-reported history of OPOR in an older, ethnically diverse population, ii). to assess the agreement between PMX/MCI findings and self-reported OPOR, and iii). to assess the likelihood of having both a self-reported history of OPOR and a diagnosis of periodontitis.

MATERIALS AND METHODS

PMX and medical history were obtained from 1084 subjects aged 60-75 (mean age 67.6, SD +/- 4.7). Of the films, 90.3% were useful for analysis. PMXs were studied using MCI. The PMXs were used to grade subjects as not having periodontitis or with one of three grades of periodontitis severity.

RESULTS

A positive MCI was found in 38.9% of the subjects, in contrast to 8.2% self-reported OPOR. The intraclass correlation between MCI and self-reported OPOR was 0.20 (P < 0.01). The likelihood of an association between OPOR and MCI was 2.6 (95%CI: 1.6, 4.1, P < 0.001). Subjects with self-reported OPOR and a positive MCI had worse periodontal conditions (P < 0.01). The Mantel-Haentzel odds ratio for OPOR and periodontitis was 1.8 (95%CI: 1.2, 2.5, P < 0.001).

CONCLUSIONS

The prevalence of positive MCI was high and consistent with epidemiological studies, but only partly consistent with a self-reported history of osteoporosis with a higher prevalence of positive MCI in Chinese women. Horizontal alveolar bone loss is associated with both positive self-reported OPOR and MCI.

Discrepancy between need for prosthodontic treatment and complaints in an elderly edentulous population

Most reports indicate that about two-thirds of the elderly population have poor oral health but that only about one-third complain of a problem. The reason for this discrepancy has never been explained adequately. The objective of this study was to estimate the need for prosthodontic treatment in an edentulous elderly population, and to identify factors associated with complaints, needs for treatment, and the use of dentures. Interviews and examinations were conducted to determine the oral health and dental concerns among 269 residents of longterm care facilities in Vancouver. The need for prosthodontic treatment was considered under theoretical, clinical, and practical conditions, and related to various factors that might help to predict this need. During the interview, about half (54%) of the sample identified a problem, and 83% of the subjects were either using a denture with a major fault or were missing a denture. Seventeen percent of the sample would not benefit from treatment because of a severely resorbed residual ridge, while the presence of a complaint combined with a prosthodontic need indicated that about one-third (36%) would seek and benefit from treatment. The proportion of subjects with complaints was larger among the more educated subjects, and among those who had been recently to a dentist. It was not possible to predict the need for treatment from any of the socioeconomic factors considered. No significant association was observed between the need for treatment and the complaints, and many subjects seemed to be resigned to their discomfort or had unrealistic expectations from their dentures.

The economics of complete dentures and implant-related services: a framework for analysis and preliminary outcomes

It is not always clear that the implant-prosthesis offers distinct advantages over the conventional complete denture for managing the edentulous jaw. This article discusses the measurement, distribution, impact, and management of the edentulous jaw, and describes a framework for analyzing the economic costs and benefits associated with the conventional denture and the implant prosthesis. There are physiologic and psychosocial costs and benefits to both the conventional denture and the implant prosthesis, which indicates that neither method is distinctly superior. The physiologic costs are low and the psychosocial costs are similar for both treatments, whereas the direct financial costs associated with the implant prosthesis are substantially higher.

Factors influencing oral health in long term care facilities

In a stratified random sample of 41 long term care (LTC) facilities in Vancouver, 653 residents were chosen to investigate oral health needs and demands for treatment. All of the 603 dentists in the same area were questioned to assess their interest in attending the residents of the institutions. The information from each source was reviewed to identify factors influencing the oral health services to this predominantly elderly and medically compromised population. The majority (60%) of the residents were edentulous and they made infrequent demands on dentists. Two-thirds of those interviewed said that there was nothing wrong with their mouths, but most of those who were aware of a problem wanted it treated, preferably within the institution. They complained about loose or uncomfortable dentures most frequently, and many were dissatisfied with previous dental treatment. The oral mucosal lesions seen on examination were usually symptomless and associated with poor hygiene, while structurally defective dentures and deep carious lesions were not uncommon. The responding 334 dentists indicated that they enjoyed treating elderly patients, 19% had attended an LTC facility, usually to provide an emergency service, and 37% were willing to provide this service if asked. Interest, however, in the service was curtailed by pressures from private practice, concerns about inadequate training and the small demand and poor conditions in the facilities. Although the demand for treatment was not extensive from the residents, they did have problems that were not receiving care.

Opinions of dentists on the treatment of elderly patients in long-term care facilities

The high prevalence of disorders in the mouths of elderly residents in long-term care (LTC) facilities suggests that the dental services available to the residents are inadequate. A questionnaire was sent to most of the dentists practicing in Vancouver (British Columbia) to solicit their opinions on treating older patients in LTC facilities, and a response was obtained from 334 (55%). It indicated that 19 percent of the respondents had treated old people within this context, although few of them felt they had been educated adequately for the service. Many reasons were offered to explain the small participation. Most respondents had never been asked to attend a facility. Many felt that it interfered with their practice and leisure, and they were concerned about the limited options available for treatment. Dentists who had attended facilities were motivated by a sense of professional or public responsibility, but they were uneasy about the limited options and about the inadequate space and equipment available. In general, the dentists were not interested in attending an institutionalized geriatric population, and they felt ill-prepared for the service.

Oral mucosal disorders in denture wearers

Patients who wear dentures present with a variety of symptoms and abnormal intraoral findings. The advanced age of the average denture wearer and the nature of the denture-bearing mucosa appear to influence the nature of the problems. Superimposed infection with candidal organisms and traumatic lesions are the most commonly encountered abnormalities. Patients with symptoms but no intraoral changes frequently had a psychologic component to their complaint and did not improve after alteration of their dentures.

The influence of social, economic, and professional considerations on services offered by dentists to long-term care residents

Many studies have focused on the disabilities and behavior of the elderly population in an attempt to explain the frequent reports of poor oral health among residents of long-term care (LTC) facilities, but little attention has been given to the experiences and opinions of dentists relating to the problem. This study was conducted to discover how dentists feel about older patients and about working in LTC facilities. A response to a questionnaire was obtained from 334 (55%) of the 603 dentists in Vancouver who treated adults. The responses were subjected to bivariate and multivariate analyses. Three models were constructed from factors that might interest a dentist in attending a patient in a facility; the factors in each model were ranked in order of importance. Interest was associated significantly with lack of concern for time lost in practice, with training in managing medically compromised patients, and with a positive attitude toward elderly patients. Dentists with fewer years in practice were attracted by the economic potential of the service, while the older and busier dentists were less involved because of the disruption to their practice and leisure. Dentists who made home visits also were more likely to be interested. The model based on professional considerations was superior to either the social or economic model in explaining an interest in the service.

Influence of age and gender on oral health and related behaviour in an independent elderly population

Previous studies have been unable to determine the influence of advanced age on oral health because they included relatively few subjects, particularly men, over 75 yr of age. In this study a disproportionate and stratified random sample of subjects over 70 yr and living independently was selected from a list of voters in Vancouver, B.C. The sample of 521 elders was structured to provide similar numbers of men and women in three 5-yr age-groups. All of the subjects were interviewed, and 255 of them, representing a similar distribution of age and gender, were examined to investigate the influence of aging on oral health and related behaviour. In bivariate analyses neither age nor gender was associated significantly with oral health or complaints. The use of dental services during the preceding year was associated with female and younger subjects, while men and older subjects usually went to dentists only to relieve pain. Logistic regression in a multivariate model confirmed the importance of natural teeth in predicting the use of dental services (by improving the prediction from 60% to 73%). Other models offered less useful improvements in predicting complaints (64% to 70%) or oral health (56% to 60%). Overall the study demonstrates that the age and gender of independent elders have very little direct influence on the oral health or related behaviour established early in life.

Oral care for successful aging in long-term care

The oral health of frail elders residing in long-term care facilities is very poor, probably because access to dental services is limited and help with daily mouth care is almost nonexistent. Recent concerns and interest have been raised through the cooperation of administrators, nursing staff, and dental personnel to address this apparent neglect. Moreover, evidence shows that caries and periodontal disorders can be managed successfully in geriatric populations. Consequently, there is a basis on which to develop a practical strategy for mouth care that should reduce the morbidity and early mortality in long-term care and to assist an increasingly frail and dependent population to age successfully.

Predictors of caries in old age

This study measured the incidence of dental caries for one year and identified factors associated with the risk of caries in a sample of 156 elderly subjects. The subjects were examined at baseline and after one year to record the number of missing, filled and decayed teeth, to measure oral hygiene and flow of saliva, and to estimate the numbers of Streptococcus mutans and Lactobacilli cultured from samples of saliva. All subjects were interviewed on both occasions for information on their use of medications and dental services and on their ingestion of sugar. At baseline the elders had a mean of 19 natural teeth with 5 decayed surfaces (DS), 38 filled surfaces and a mean Plaque Index (PI) of 1. The independent group, on average, had more teeth and fillings but a lower PI and less caries. At the end of the year more than two-thirds (71%) of the 98 institutionalised subjects and over half (59%) of the 58 independent subjects had at least one new decayed/filled surface (DFS). The mean net DFS increment per subject was 4.6 and 2.0 respectively. Regression analyses on multivariate models identified caries at baseline, residence in long term care facilities, high numbers of Lactobacilli, poor oral hygiene and frequent sugar consumption as the variables contributing most significantly to the risk of caries in old age.

Assessment of periodontal conditions and systemic disease in older subjects

BACKGROUND

An increased risk for periodontitis has been associated both with type-1 or insulin dependent diabetes (IDDM) and with type-2 or non-insulin dependent diabetes (NIDDM).

AIMS

1) To describe and analyze periodontal conditions in older low-income ethnic diverse subjects with or without a diagnosis of diabetes. 2) To assess to what extent diabetes mellitus is associated with periodontal status, and 3) how periodontitis ranks as a coexisting disease among other diseases in subjects with diabetes mellitus.

MATERIAL AND METHODS

Radiographic signs of alveolar bone loss were studied in 1101 older subjects 60-75 years old (mean age 67.6, SD+/-4.7). The number of periodontal sites and the proportions of teeth with probing depth (PD) > or =5 mm, clinical attachment levels (CAL) > or =4 mm were studied in a subset of 701 of the subjects.

RESULTS

IDDM was reported by 2.9% and NIDDM by 9.2% of the subjects. The number of remaining teeth did not differ by diabetic status. The number of sites with PD > or =5 mm and the proportion of PD with > or =5 mm was significantly smaller in the non-diabetic group (chi2=46.8, p<0.01, and chi2=171.1, p<0.001, respectively). Statistical analysis failed to demonstrate group differences for the number and proportions of sites with CAL > or =4 mm and for radiographic findings of alveolar bone loss. Combining all periodontal parameters revealed that the Mantel-Haenszel common odds of having IDDM/NIDDM and periodontitis was 1.8 : 1 (95% CI: 1.1-3.1, p<0.03). The common odds ratio estimate of an association between heart disease and diabetes was 3.6 : 1 (95% CI: 2.1-2.6, p<0.001).

CONCLUSIONS

Probing depth differences between IDDM/NIDDM vs. non-diabetic subjects may reflect the presences of pseudo-pockets and not progressive periodontitis in many subjects with diabetes mellitus. Periodontitis is not a predominant coexisting disease in older subjects with diabetes mellitus.

Short-term contamination of luting cements by water and saliva

OBJECTIVES

The aim of this study was to determine the effect of water, artificial saliva and natural saliva on the hardening process of three dental luting cements.

METHODS

Cement samples, 1 mm thick and 5 mm in diameter, were subjected to various storage conditions in an oven maintained at 37 degrees C. Some samples were aged in 100% humidity or water for up to 1 wk. The other samples were covered with water, artificial saliva or natural saliva at various times after mixing. The Knoop hardness values of the cement surfaces were measured. Differences between groups were evaluated with an ANOVA followed by a Tukey multiple comparison at the 5% level of significance. The hardness ratio of the contaminated samples was calculated using the 30 min mean KHN of the samples aged in 100% humidity as the divisor.

RESULTS

The glass ionomer samples were significantly harder (48.3 +/- 3.8) than the zinc phosphate (38.9 +/- 7.5) or composite cements (35.4 +/- 10.2) after 1 wk in 100% humidity storage condition. When immersed in water, the hardness of both the glass ionomer and the zinc phosphate decreased to almost half that of the specimens stored in 100% humidity (26.2 +/- 2.7 and 16.9 +/- 2.5, respectively). Contamination decreased the hardness of zinc phosphate and glass ionomer (hardness ratio, water contamination at 5 min: 0.39 +/- 0.10 and 0.52 +/- 0.12, respectively) but had very little effect on the composite. Overall, water had a greater softening effect than artificial or natural saliva on the cements.

SIGNIFICANCE

In light of these results, glass ionomer cement should be protected from water and saliva for the first 15 min after mixing.

Estimates of time and propensity for dental treatment among institutionalised elders

The oral health and concerns of elderly residents were surveyed in a stratified random selection of 41 long-term care facilities in Vancouver. The residents who could participate were examined and interviewed to determine their oral health and concerns about dental treatment. The need and time required for treatment were estimated in six groups to reflect the propensity for treatment in dentate and edentate subjects. The propensity for treatment was high in about one-third of the participants whereas it was unlikely that one-tenth of those examined would ever use a dental service. In general, there was a widespread need for a diagnostic service because so few had been examined by a dentist in the previous year. Prosthodontics accounted for most of the treatment in all of the propensity groups, with substantially more time required by the dentate residents. There was also a substantial need for management of mucosal pathoses and oral hygiene and, to a lesser extent, for dental restorations and endodontics. Overall, our estimates indicate a substantial need for dental treatment among residents of long-term care facilities, although the need is reduced by half if the propensity for treatment is considered.

Chlorhexidine and Preservation of Sound Tooth Structure in Older Adults

The Trial to Enhance Elderly Teeth Health (TEETH) was designed to test the impact of regular rinsing with a 0.12% chlorhexidine (CHX) solution on tooth loss, and the causes of tooth loss (caries, periodontal disease and trauma) were also investigated. This paper reports on the effectiveness of a 0.12% CHX solution for controlling caries using a tooth surface (coronal and root) survival analysis. A total of 1,101 low income elders in Seattle (United States) and Vancouver (Canada), aged 60-75 years, were recruited for a double-blind clinical trial and assigned to either a CHX (n = 550) or a placebo (n = 551) mouth rinse. Subjects alternated between daily rinsing for 1 month, followed by weekly rinsing for 5 months. All sound coronal and root surfaces at baseline were followed annually for up to 5 years. At each follow-up examination, those tooth surfaces with caries, restored, or extracted were scored as 'carious'. The hazard ratio associated with CHX for a sound surface to become filled, decayed, or extracted was 0.87 for coronal surfaces (95% confidence interval: 0.71-1.14, p = 0.20) and 0.91 for root surfaces (95% confidence interval: 0.73-1.14, p = 0.41). These findings suggest that regular rinsing with CHX does not have a substantial effect on the preservation of sound tooth structure in older adults.

Personal identification using dental prostheses

A personal identity mark may be added to a metal or an acrylic resin prosthesis. The importance of this technique, particularly in terms of forensic investigation and identification, should make it a compulsory dental procedure. Where metal is involved, engraving is the most desirable method of marking. The heat resistance of various labeling materials indicates that an acrylic resin prosthesis should contain a marked, heat resistant material together with a mark clearly visible from the denture surface.