Practice variation: learned and socio-economic factors.

Much variation exists in the practice of dentistry with regard to diagnosis of caries and recommendations for treatment. This is a particular problem with respect to the replacement of restorations, with responsible factors related to both the patient and the dentist. The aim of this paper is to look at factors, exclusive of clinical data, that may explain why there is so much variation in the practice of dentistry, and specifically pertaining to replacement of restorations. Due to the paucity of studies related specifically to dentists, findings from physician studies will be presented. No studies are available that compare variation in medical and dental practices, but since both professions deal with the provision of health care and function in similar circumstances, comparisons are arguably generalizable between the two groups. Development of clinical judgment will be explored based on dental training experiences, and two explanatory models of practice pattern variation will be discussed--the dentist as a self-fulfilling practitioner and the dentist as the patient's agent. Along with these models, the matter of uncertainty in clinical practice and the development of routines will also be discussed in light of explaining variations.

Reasons for restoration replacement: differences in practice patterns.

Patients receive varying types and amounts of restorative treatment, depending on the prescribing dentist. The aim of this study was to enhance the understanding of the variation of the restoration replacement practices of dentists. Three dentists in private practice in similar semirural communities with comparable practice demographics were asked to gather data on all restorations they replaced over a period of 1 month. They recorded the tooth number, number of restored surfaces, restorative material being replaced, number of surfaces in the replacement restoration, the replacement restorative material, and the reasons for the replacement restoration. Statistically significant differences were found among the dentists as to the reasons for posterior restoration replacement, replacement materials used, and increase in size of the replacement restorations. Differences were attributed to individual practice philosophies, demonstrating that clinical information was not the sole determining factor as to type of replacement restorations that patients received.

Placement of cast restorations over direct pulp capping procedures: a decision analytic approach.

A review of the literature shows a significant amount of controversy regarding the success of pulp capping procedures, with the average clinically evaluated pulp capping success being 81%, and 75% when evaluated histologically. This study evaluated the costs and benefits of a pulp cap versus endodontic therapy for a tooth that is to receive a cast restoration, and determined what level of success is needed for pulp capping to be the preferred treatment.

Replacement of amalgams with crowns: a cost-effectiveness analysis.

No formal analyses comparing the treatment alternatives of replacing a failed amalgam with either another amalgam or crown have been done to determine the optimum treatment strategy based on lifetime costs to the patient. Using decision analysis, a computer model was developed of the lifetime restorative needs of an adult's posterior tooth. A cost-effectiveness analysis of large amalgams vs crowns was then done to determine the optimum strategy. According to the analyses, the optimum treatment decision is to attempt to replace the failed first amalgam with another amalgam, instead of with a crown. When this amalgam restoration fails, then the subsequent replacement may be with a crown. Potential lifetime cost savings were between 11% and 24% if the first replacement was an amalgam. This study concludes that the technique of decision analysis provides the dental community with an effective evaluation tool for the study of clinical decision-making, taking into account all levels of clinical uncertainty.

Is periodontal disease the primary cause of tooth extraction in adults?

Preventing caries and reducing out-of-pocket costs for dental services are two strategies proposed by the authors to lower the rate of tooth extractions. Efforts also must be made to change public values about the importance of restoring rather than extracting carious teeth.

Longevity of restorations: survey results of dentists' estimates and attitudes.

A cross-sectional survey of 571 clinicians was conducted to obtain information about expected and observed restoration longevity. Clinicians believed that average large amalgam, small amalgam, and cast restorations lasted 6, 11, and 13 years, respectively. Patients were thought to be responsible for 47%, dentists for 30%, and materials used for 23% of restoration failures. The clinicians perceived the restorations that they placed to be more long-lasting than those placed by other clinicians. Clinical measurements of restoration longevity were shown to be influenced by the judgment criteria used by clinicians.

In search of treatment longevity--a 30-year perspective.

Consumers spent $10 billion on restorative dental treatment in 1979. Little information is available regarding the life expectancy of these restorations or what proportion of these restorations replaces previous ones. A critical literature review was presented, covering all available longevity data of posterior restorations. Necessary methodologic standards for evaluation of the studies were outlined and used in the review. The lack of these critical variables--patient selection, missing follow-up data, and judgment criteria for determining need for replacement or failure (or both)--minimized the usefulness of the results. Study results are generalizable only to similar patient populations and not all patients. Much more controlled research needs to be done.

Effects of canal lubrication on retention of cemented posts.

The effect of lubricating the canal space prior to making a custom acrylic post pattern was studied in regard to the retention of cast posts cemented with zinc phosphate. Ways of removing the lubricant before cementation were also evaluated.