Evidence-based dentistry: prognosis

Making the Best Clinical Decisions for Patients: The Pros-CAT ProtocolTM

The Pros-CAT protocol critical appraisal method uses accepted strategies to identify and summarize best evidence to support patient care through evidence-based analysis that includes assessing the patient; developing a concise clinical question; conducting a literature search to identify pertinent research; critically appraising the identified literature for validity, reliability, and applicability to the patient situation; synthesizing the literature into a meaningful conclusion using an organized method; and applying that synthesis to the patient's need. The Pros-CAT protocol is applicable for practicing clinicians, dental students, postgraduate students, and residents. The Pros-CAT index compares evidence strength for patient applicability.

Standard of care for the edentulous mandible: A systematic review

STATEMENT OF PROBLEM

Implant therapies have increased the range of prosthodontic options for the treatment of edentulism. Considering both dentist- and patient-mediated outcomes, a universal treatment intervention for the treatment of the edentulous mandible has not been demonstrated.

PURPOSE

The purpose of this study was to test the null hypothesis that there is no single standard of care for the edentulous mandible as defined by a specific treatment modality.

MATERIAL AND METHODS

A review of the literature was undertaken seeking evidence of a superior intervention for the treatment of the edentulous mandible. A search of the English language peer-reviewed literature was completed using Medline and Google Scholar for the period from 1995 to 2005, focusing on evidence-based research. This was supplemented with a hand search of selected dental journals and textbooks. Longitudinal retrospective studies, longitudinal prospective studies, longitudinal experimental clinical studies, nonrandomized controlled studies, and randomized controlled clinical trials were included for review using a general linear hierarchical classification of studies. Articles that did not focus exclusively on treatment interventions for mandibular edentulism or on the effects of such therapies on the patient were excluded from further evaluation. The search period included articles that were published before the criteria for evidence-based literature were established, but this was not necessarily used to exclude an article. The last search was conducted on September 25, 2005.

RESULTS

The literature demonstrates that the functional demands of edentulous patients are highly variable and that patient treatment responses are individual, vary significantly, and are influenced by psychosocial forces. The literature further demonstrates that patient acceptance of specific treatment modalities is modified by social and cultural influences, financial means, and adaptive capacity. Additionally, patient acceptance of a particular treatment modality is influenced by the educational background, knowledge, and experience of the dental health care provider, as well as by a host of other socioeconomic, regional, cultural, age, and gender influences.

CONCLUSIONS

Within the limits of this review, there is no evidence for a single, universally superior treatment modality for the edentulous mandible. Better designed, long-term studies are required to further explore differences in patient acceptance to each treatment intervention for the edentulous mandible.

Long-term survival of primary root canal treatment carried out in a dental teaching hospital

AIM

This study aimed to examine clinically and radiographically the survival of primary root canal treatment completed in a dental teaching hospital between 10 and 20 years previously.

METHODOLOGY

A data collection form was used to collate all information obtained from the written patients' records along with the results from clinical and radiographic examination of 608 teeth, out of a total of 986 randomly selected teeth that had been root filled in the Prince Philip Dental Hospital (PPDH), Hong Kong, between 1981 and 1989. The criteria for failure were extractions (except for documented nonendodontic reason), retreatments and presence of a periapical radiolucency. The survival function of the treated teeth was plotted against the calculated date of failure using the Kaplan-Meier (K-M) method. Covariables were examined further by Cox Regression analysis with a backward stepwise method.

RESULTS

A total of 314 teeth (52%) were either documented or deemed to have failed after examination. The median survival time was 111 months. Cox Regression analysis indicated that the survival of root-filled teeth was significantly influenced by the tooth type, preoperative periapical status and the type of coronal restoration. The survival function declined with time, with a rapid drop in the first 18 months or so. The rate at which failures occurred appeared to slow down with a longer observation time.

CONCLUSIONS

There was a nonlinear decline in the cumulative survival probability of primary root canal treatment. Tooth type, preoperative periapical status and type of post and final restoration significantly affected the long-term survival of the treated teeth.

Survival of first-time nonsurgical root canal treatment performed in a dental teaching hospital

OBJECTIVE

The purpose of this study was to use survival analysis to evaluate the long-term treatment outcome of first-time, nonsurgical root canal therapy performed in a dental teaching hospital and to identify factors that might affect that outcome.

STUDY DESIGN

One-tenth of all teeth treated between 1989 and 1994 were sampled. Patients were invited to return for a recall and were examined both clinically and radiographically. Any teeth that had been extracted or retreated or that were associated with a periapical radiolucency or presented with clinical signs and symptoms were deemed to have failed. An adjusted date of failure was calculated in the survival analysis by means of the Kaplan-Meier method. Ten covariables were further analyzed with the Cox regression model by using a backward stepwise regression method.

RESULTS

Of 550 sampled teeth, 251 were examined. The mean observation period was 74 months. The failure rate was 44% (n = 111), with a median survival time of 113 months (mean, 91 months). Use of the Cox Regression model revealed that tooth type was significant in affecting the survival time of the treatment. Radiographic presence of voids in the apical and middle thirds of root canal fillings was associated with a significantly lower mean survival time than the presence of voids found in the coronal third or no void at all. The use of a calcium hydroxide dressing after initial treatment was associated with a longer survival time than failure to use medication or dressing with Ledermix alone.

CONCLUSION

Simple calculation of percentages did not provide sufficient information on the treatment prognosis. The survival of first-time root canal therapy was significantly influenced by the tooth type, radiographic location of voids in the root canal filling, and the intracanal medicament used.

What is evidence based dentistry?

The insurmountable mass of literature and lectures that the modern practitioner is exposed to has created problems. The resolution of often contradictory information is not easy to discern. Evidence based dentistry presents guidelines to determine the validity of the results and whether they can be applied to clinical practice. This article introduces the reader to the basic principles to be used in and evidence based practice.

Systematic reviews of the literature: the overview and meta-analysis

Systematic reviews in the form of overviews or meta-analyses offer a solution for busy practitioners who have difficulty keeping abreast of current literature. Because systematic reviews can condense numerous studies into reliable and valid summaries of the best available evidence for a specific clinical problem, they offer significant benefit to busy clinicians. This article has summarized the major features and advantages of systematic reviews. It has distinguished those features that attempt to increase the usefulness of reviews by limiting bias, and it provided a summary of important questions clinicians can use to appraise such reviews critically. With this knowledge, clinicians should be able to use the literature more appropriately and in a timely fashion.