Root Canal Treatment Survival Analysis in National Dental PBRN Practices.

Few studies have examined the longevity of endodontically treated teeth in nonacademic clinical settings where most of the population receives its care. This study aimed to quantify the longevity of teeth treated endodontically in general dentistry practices and test the hypothesis that longevity significantly differed by the patient's age, gender, dental insurance, geographic region, and placement of a crown and/or other restoration soon after root canal treatment (RCT). This retrospective study used deidentified data of patients who underwent RCT of permanent teeth through October 2015 in 99 general dentistry practices in the National Dental Practice-Based Research Network (Network). The data set included 46,702 patients and 71,283 RCT permanent teeth. The Kaplan-Meier (product limit) estimator was performed to estimate survival rate after the first RCT performed on a specific tooth. The Cox proportional hazards model was done to account for patient- and tooth-specific covariates. The overall median survival time was 11.1 y; 26% of RCT teeth survived beyond 20 y. Tooth type, presence of dental insurance any time during dental care, placement of crown and/or receiving a filling soon after RCT, and Network region were significant predictors of survival time (P < 0.0001). Gender and age were not statistically significant predictors in univariable analysis, but in multivariable analyses, gender was significant after accounting for other variables. This study of Network practices geographically distributed across the United States observed shorter longevity of endodontically treated permanent teeth than in previous community-based studies. Also, having a crown placed following an RCT was associated with 5.3 y longer median survival time. Teeth that received a filling soon after the RCT before the crown was placed had a median survival time of 20.1 y compared to RCT teeth with only a crown (11.4 y), only a filling (11.2 y), or no filling and no crown (6.5 y).

Differences between reported and actual restored caries lesion depths: results from The Dental PBRN.

OBJECTIVE: The objectives of this research were to: (1) quantify the discordance between the caries lesion depth at which dentists restored initial lesions during a clinical study ("actual depth") and the lesion depth that they reported during a hypothetical clinical scenario ("reported depth"); (2) test the hypothesis that certain practitioner, practice, patient, and caries lesion characteristics are significantly associated with this discordance. METHODS: Practitioner-investigators who perform restorative dentistry in their practices completed an enrollment questionnaire and participated in 2 consecutive studies on caries diagnosis and treatment. The first study was a survey asking about caries treatment. The second study collected data on restorations placed in routine clinical practice due to caries in patients over 19 years of age on occlusal surfaces only or proximal surfaces only. We report results on 2,691 restorations placed by 205 dentists in 1,930 patients with complete data. RESULTS: Discordance between actual depth and reported depth occurred in only about 2% of the restorations done due to proximal caries, but about 49% of the restorations done due to occlusal caries. Practice type, restorative material used and the diagnostic methods used were significantly associated with discordance. CONCLUSION: Dentists frequently restored occlusal caries at a shallower depth as compared to their reported depth, but the discordance was very small for proximal lesions. Discordance for occlusal caries was more common when radiographs were not taken or if a resin restoration was placed.

Characteristics, detection methods and treatment of questionable occlusal carious lesions: findings from the national dental practice-based research network.

Questionable occlusal carious lesions (QOC) can be defined as an occlusal tooth surface with no cavitation and no radiographic radiolucencies, but caries is suspected due to roughness, surface opacities or staining. An earlier analysis of data from this study indicates 1/3 of patients have a QOC. The objective of this report has been to quantify the characteristics of these common lesions, the diagnostic aids used and the treatment of QOC. A total of 82 dentist and hygienist practitioner-investigators from the USA and Denmark in the National Dental Practice-Based Research Network participated. When consenting patients presented with a QOC, information was recorded about the patient, tooth, lesion and treatments. A total of 2,603 QOC from 1,732 patients were analyzed. The lesions were usually associated with a fissure, on molars, and varied from yellow to black in color. Half presented with a chalky luster and had a rough surface when examined with an explorer. There was an association between color and luster: 10% were chalky-light, 47% were shiny-dark and 42% were mixtures. A higher proportion of chalky than of shiny lesions were light (22 vs. 9%; p < 0.001). Lesions light in color were less common in adults than in pediatric patients (9 vs. 32%; p < 0.001). Lesions that were chalky and light were more common among pediatric than among adult patients (22 vs. 6%; p < 0.001). This is the first study to investigate characteristics of QOC in routine clinical practice. Clinicians commonly face this diagnostic uncertainty. Determining the characteristics of these lesions is relevant when making diagnostic and treatment decisions.

Cluster Effects in a National Dental PBRN restorative study.

Items in clusters, such as patients of the same clinician or teeth within the same patient, tend to be more similar than items from different groups. This within-group similarity, represented by the intraclass correlation coefficient (ICC), reduces precision, yielding less statistical power and wider confidence intervals, compared with non-clustered samples of the same size. This must be considered in the design of studies including clusters. We present ICC estimates from a study of 7,826 restorations placed in previously unrestored tooth surfaces of 4,672 patients by 222 clinicians in the National Dental Practice-Based Research Network, as a resource for sample size planning in restorative studies. Our findings suggest that magnitudes of ICCs in practice-based research can be substantial. These can have large effects on precision and the power to detect treatment effects. Generally, we found relatively large ICCs for characteristics that are influenced by clinician choice (e.g., 0.36 for rubber dam use). ICCs for outcomes within individual patients, such as tooth surfaces affected by a caries lesion, tended to be smaller (from 0.03 to 0.15), but were still sufficiently large to substantially affect statistical power. Clustering should be taken into account in the design of oral health studies and derivation of statistical power estimates for these studies (ClinicalTrials.gov, NCT00847470).

ONJ in two dental practice-based research network regions.

The incidence of osteonecrosis of the jaw (ONJ) in the population is low, but specifics are unknown. Potential risk factors include bisphosphonate treatment, steroid treatment, osteoporosis, and head/neck radiation. This Dental Practice-Based Research Network study estimated ONJ incidence and odds ratios from bisphosphonate exposure and other risk factors using a key word search and manual chart reviews of electronic records for adults aged > or = 35 years enrolled during 1995-2006 in 2 large health care organizations. We found 16 ONJ cases among 572,606 cohort members; 7 additional cases were identified through dental plan resources. Among 23 cases (0.63 per 100,000 patient years), 20 (87%) had at least 1 risk factor, and 6 (26%) had received oral bisphosphonates. Patients with oral bisphosphonates were 15.5 (CI, 6.0-38.7) more likely to have ONJ than non-exposed patients; however, the sparse number of ONJ cases limits firm conclusions and suggests that the absolute risks for ONJ from oral bisphosphonates is low.

Differences between reported and actual restored caries lesion depths: results from The Dental PBRN.

OBJECTIVE: The objectives of this research were to (1) quantify the discordance between the caries lesion depth at which dentists restored initial lesions during a clinical study ("actual depth") and the lesion depth that they reported during a hypothetical clinical scenario ("reported depth"); (2) test the hypothesis that certain practitioner, practice, patient, and caries lesion characteristics are significantly associated with this discordance. METHODS: Practitioner-investigators who perform restorative dentistry in their practices completed an enrollment questionnaire and participated in two consecutive studies on caries diagnosis and treatment. The first study was a survey asking about caries treatment. The second study collected data on restorations placed in routine clinical practice due to caries in patients over 19 years of age on occlusal surfaces only or proximal surfaces only. We report results on 2691 restorations placed by 205 dentists in 1930 patients with complete data. RESULTS: Discordance between actual depth and reported depth occurred in only about 2% of the restorations done due to proximal caries, but about 49% of the restorations done due to occlusal caries. Practice type, restorative material used and the diagnostic methods used were significantly associated with discordance. CONCLUSION: Dentists frequently restored occlusal caries at a shallower depth as compared to their reported depth, but the discordance was very small for proximal lesions. Discordance for occlusal caries was more common when radiographs were not taken or if a resin restoration was placed.

ONJ in two dental practice-based research network regions.

The incidence of osteonecrosis of the jaw (ONJ) in the population is low, but specifics are unknown. Potential risk factors include bisphosphonate treatment, steroid treatment, osteoporosis, and head/neck radiation. This Dental Practice-Based Research Network study estimated ONJ incidence and odds ratios from bisphosphonate exposure and other risk factors using a key word search and manual chart reviews of electronic records for adults aged ≥ 35 yrs enrolled during 1995-2006 in two large health-care organizations. We found 16 ONJ cases among 572,606 cohort members; seven additional cases were identified through dental plan resources. Among 23 cases (0.63 per 100,000 patient years), 20 (87%) had at least one risk factor, and six (26%) had received oral bisphosphonates. Patients with oral bisphosphonates were 15.5 (CI, 6.0-38.7) more likely to have ONJ than non-exposed patients; however, the sparse number of ONJ cases limits firm conclusions and suggests that the absolute risks for ONJ from oral bisphosphonates is low.

Influence of flexible nailing in the later phase of fracture healing: strength and mineralization in rat femora.

In this experimental study, the influence of flexible nailing in the later phase of femoral fracture healing was investigated. Sixty rats were randomly assigned to three groups. In 20 rats no intervention was performed, and they served as a control group. Fracture and reamed nailing with a rigid steel nail was performed in the left femur in the other 40 rats. These rats were reoperated after 30 days, and the medullary nail was removed. In one group (20 rats) a flexible polyethylene nail was installed (flexibly nailed group), while the rats in the other group received a steel nail identical to the one that was removed (rigidly nailed group). At 60 and 90 days, the left femurs of 10 animals in each group were studied clinically, radiologically, and biomechanically, and bone mineralization was measured by dual-energy X-ray absorptiometry. Radiographs in two planes revealed a clearly visible fracture line in both intervention groups at 60 days. At 90 days, the fracture line was clearly visible in the flexibly nailed group, while bridging callus was apparent after the rigid nailing. At 60 and 90 days, the callus area in the flexibly nailed group was significantly larger than that in the rigidly nailed bones. Biomechanically, flexible nailing reduced maximum bending load and fracture energy at 60 and 90 days compared with findings in rigidly nailed bones, while bending rigidity was similar in the two groups. All values for biomechanical characteristics were reduced at 60 and 90 days in flexibly nailed bones compared with intact femurs, while in the rigid nailing group, bending load and fracture energy were similar to those in intact bones at 90 days. Bone mineral content in the callus segment and diaphysis was greater in the rigidly nailed bones than in the flexible nailing group at 60 days, while at 90 days, no differences were detected. In conclusion, this animal study indicates that: (1) flexible nailing in the later phase of fracture healing increases callus formation, while (2) the quality of bone healing is reduced.

Effects of torsional rigidity on fracture healing: strength and mineralization in rat femora.

OBJECTIVE: To assess the effects of torsional rigidity and dynamization on fracture healing in a medullary nailed rat femoral model. STUDY DESIGN: Randomized study in male Wistar rats with a diaphyseal osteotomy/fracture. METHODS: Reamed cannulated nailing was performed in sixty rats. One group (twenty rats) received unlocked nails (UL group) and another group received nails with proximal and distal locking that was dynamized after twenty days (DL group). The third group was statically locked (SL group). A fourth group of twenty rats served as the control group. After randomization, the femurs of ten rats in each group at six and twelve weeks were studied clinically, radiologically, and biomechanically, and bone mineralization was measured by dual-energy x-ray absorptiometry (DEXA). RESULTS: Radiographs in two planes revealed clearly visible fractures at six weeks, and at twelve weeks bridging callus was apparent in all three treatment groups. The callus area in the UL group was significantly larger at six weeks than in the other groups, and at twelve weeks the UL and DL groups had larger callus areas than the SL group. Biomechanically, UL nails had reduced maximum bending load at six and twelve weeks, while DL nails had increased fracture energy at six weeks compared with SL nails. Bone mineral content and bone mineral density in the callus segment and diaphysis were increased with DL nails at six weeks. CONCLUSION: This animal study indicates that (a) interlocked nailing has a beneficial effect on bone healing and (b) although dynamization may have a beneficial effect on the quality of early bone healing, (c) dynamization does not increase the rate of bony union. The clinical implication is that routine early dynamization of locked femoral fractures may not be indicated, reserving dynamization to cases of delayed union.

Development of effectiveness of care and use of services measures for dental care plans.

OBJECTIVES: Standardized measures to assess clinical aspects of the performance of managed dental care plans are not available. This project sought to develop and evaluate measures for effectiveness of care and use of services that could be calculated using a plan's administrative data. METHODS: Two panels of stake holders representing dental plans, purchasers, and dental providers participated in a modified Delphi process to refine initial sets of effectiveness of care and use of services measures modeled after HEDIS measures for medical care. The refined measures were then pilot tested in two dental health maintenance organizations. RESULTS: The development process resulted in specification of seven effectiveness of care measures assessing disease activity classification, and prevention and outcomes for caries, periodontal disease, and tooth loss. Six use of services measures focusing on prophylaxes, third molar surgery, preventive, restorative, prosthetic, surgical, and endodontic care also were specified. Pilot testing of the measures indicated reasonable reliability and sensitivity, but also demonstrated the need for supervision or auditing of the process. CONCLUSIONS: These standardized measures for dental care plan performance are available for immediate use. However, because the measures depend on diagnostic information (periodontal probing data and diagnoses associated with restorative treatments) in the administrative data set, their adoption will require changes in most plans' data systems and data collection policies.

Evaluation of audit-based performance measures for dental care plans.

OBJECTIVES: Although a set of clinical performance measures, i.e., a report card for dental plans, has been designed for use with administrative data, most plans do not have administrative data systems containing the data needed to calculate the measures. Therefore, we evaluated the use of a set of proxy clinical performance measures calculated from data obtained through chart audits. METHODS: Chart audits were conducted in seven dental programs--three public health clinics, two dental health maintenance organizations (DHMO), and two preferred provider organizations (PPO). In all instances audits were completed by clinical staff who had been trained using telephone consultation and a self-instructional audit manual. The performance measures were calculated for the seven programs, audit reliability was assessed in four programs, and for one program the audit-based proxy measures were compared to the measures calculated using administrative data. RESULTS: The audit-based measures were sensitive to known differences in program performance. The chart audit procedures yielded reasonably reliable data. However, missing data in patient charts rendered the calculation of some measures problematic--namely, caries and periodontal disease assessment and experience. Agreement between administrative and audit-based measures was good for most, but not all, measures in one program. CONCLUSIONS: The audit-based proxy measures represent a complex but feasible approach to the calculation of performance measures for those programs lacking robust administrative data systems. However, until charts contain more complete diagnostic information (i.e., periodontal charting and diagnostic codes or reason-for-treatment codes), accurate determination of these aspects of clinical performance will be difficult.