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Subgingival restorations may be associated with periodontal plaque inflammation
A RT I C L E A N A LY S I S & E VA LUAT I O N Subgingival restorations may be associated with periodontal plaque inflammation Original Article:
Schätzle M, Lang NP, Ånerud Å, Boysen H, Bürgin W, Löe H. The influence of margins of restorations on the periodontal tissues over 26 years. J Clin Periodontol 2001;28:57-64.
• Level of Evidence: • Purpose:
4
• Source of Funding:
Clinical Research Foundation for the Promotion of Oral Health, University of Berne, Switzerland
• Type of Study/Design:
Cohort study
Investigate the long-term relationship between periodontal health and subgingivally placed restorations
SUMMARY SUBJECTS Subject data were derived from a subset of longitudinal study of the initiation and progression of periodontal disease in human beings. Conducted between 1969 and 1995, 7 surveys were made during that period in 160 subjects. At the initial visit, there were 159 control cohorts and 69 test cohorts; 26 years later (1995), data were obtained from 53 control and 28 test cohorts.
EXPOSURE The progression of periodontal
status as influenced by the placement of subgingival margins in a patient population receiving regular dental care was examined.
MAIN OUTCOME MEASURE The main outcome measures were attachment levels, gingival health (PlI, GI), and restoration indices. MAIN RESULTS The PlI increased significantly (P < .05) for the test sites between the first and second surveys and reached averages of PlI =1.57-
1.77, whereas the PlI for the control sites remained fairly constant (PlI = 1.43-1.54). The GI was significantly greater (P < .005) in the test sites at all observation periods (GI = 1.03-1.38) compared to the control sites (GI = 0.47-0.88). No difference in the mean loss of attachment was evident between the test and control groups until year 4. Between years 4 and 19, greater attachment level loss was present in the test group (P < .05). However, this difference was no longer significant at year 26.
J Evid Base Dent Pract 2001;1:186-7 Copyright © 2001 by Mosby, Inc doi:10.1067/med.2001.120211
186
Fig 5. Mean loss of attachment (mm) for the control and test sites for 26 years. (Reprinted from Schätzle M, Lang NP, Ånerud Å, et al. J Clin Periodontol 2001;28:57-64. By permission.)
COMMENT ARY CONCLUSIONS This study confirms the concept that restorations placed below the gingival margin are detrimental to gingival and periodontal health. Loss of attachment started slowly, could be detected at year 3, but “burned-out” at year 19. ANALYSIS This study is significant as it is the first to examine the relationship between the location of the restoration and gingival and periodontal health over a 26-year period. At all points of examination during the 26-year period, the degree of inflammation tended to be greater at subgingival restoration sites. The present study has documented a time sequence between the placement of the subgingival restoration and the diagnosed loss of periodontal support. The analytic methodology used has several important limitations. The data for this 26-year longitudinal study consist of dental site-specific measures at each of 7 examinations. The unit of analysis is the dental site. The authors report that
• Content Reviewer: • Biostatistical/Epidemiology Reviewer: Journal of Evidence-Based Dental Practice Volume 1, Number 3
the data analysis consisted of Student t test for independent samples for comparing test sites and control sites between surveys 1 and 2. The authors also report testing for significant changes in variables between each pair of successive surveys with the Wilcoxon rank test. The first limitation is that the analyses have not accounted for the extravariation associated with correlated data where multiple sites are used from a given subject in any 1 examination. Without accounting for correlated data, the variance estimates and the resulting P values, as reported, may be inaccurate. Another limitation is the absence of adjustment for multiple comparisons where measurements of outcome variables for the test and control sites are compared at each pair of successive surveys (6 comparisons). Finally, the analyses do not include adjustment for variables like age or smoking that might modify or confound the periodontal tissue changes observed. These limitations in the statistical analyses presented in this report make this reviewer hesitant to accept the statistical significance of the conclusions reached by the authors.
Kevin G. Murphy, DDS, MS, Baltimore, Md George W.Taylor, DMD, DrPH, University of Michigan, Ann Arbor Schätzle et al 187
Schätzle M, Lang NP, Ånerud Å, Boysen H, Bürgin W, Löe H. The influence of margins of restorations on the periodontal tissues over 26 years. J Clin Periodontol 2001;28:57-64.
• Level of Evidence: • Purpose:
4
• Source of Funding:
Clinical Research Foundation for the Promotion of Oral Health, University of Berne, Switzerland
• Type of Study/Design:
Cohort study
Investigate the long-term relationship between periodontal health and subgingivally placed restorations
SUMMARY SUBJECTS Subject data were derived from a subset of longitudinal study of the initiation and progression of periodontal disease in human beings. Conducted between 1969 and 1995, 7 surveys were made during that period in 160 subjects. At the initial visit, there were 159 control cohorts and 69 test cohorts; 26 years later (1995), data were obtained from 53 control and 28 test cohorts.
EXPOSURE The progression of periodontal
status as influenced by the placement of subgingival margins in a patient population receiving regular dental care was examined.
MAIN OUTCOME MEASURE The main outcome measures were attachment levels, gingival health (PlI, GI), and restoration indices. MAIN RESULTS The PlI increased significantly (P < .05) for the test sites between the first and second surveys and reached averages of PlI =1.57-
1.77, whereas the PlI for the control sites remained fairly constant (PlI = 1.43-1.54). The GI was significantly greater (P < .005) in the test sites at all observation periods (GI = 1.03-1.38) compared to the control sites (GI = 0.47-0.88). No difference in the mean loss of attachment was evident between the test and control groups until year 4. Between years 4 and 19, greater attachment level loss was present in the test group (P < .05). However, this difference was no longer significant at year 26.
J Evid Base Dent Pract 2001;1:186-7 Copyright © 2001 by Mosby, Inc doi:10.1067/med.2001.120211
186
Fig 5. Mean loss of attachment (mm) for the control and test sites for 26 years. (Reprinted from Schätzle M, Lang NP, Ånerud Å, et al. J Clin Periodontol 2001;28:57-64. By permission.)
COMMENT ARY CONCLUSIONS This study confirms the concept that restorations placed below the gingival margin are detrimental to gingival and periodontal health. Loss of attachment started slowly, could be detected at year 3, but “burned-out” at year 19. ANALYSIS This study is significant as it is the first to examine the relationship between the location of the restoration and gingival and periodontal health over a 26-year period. At all points of examination during the 26-year period, the degree of inflammation tended to be greater at subgingival restoration sites. The present study has documented a time sequence between the placement of the subgingival restoration and the diagnosed loss of periodontal support. The analytic methodology used has several important limitations. The data for this 26-year longitudinal study consist of dental site-specific measures at each of 7 examinations. The unit of analysis is the dental site. The authors report that
• Content Reviewer: • Biostatistical/Epidemiology Reviewer: Journal of Evidence-Based Dental Practice Volume 1, Number 3
the data analysis consisted of Student t test for independent samples for comparing test sites and control sites between surveys 1 and 2. The authors also report testing for significant changes in variables between each pair of successive surveys with the Wilcoxon rank test. The first limitation is that the analyses have not accounted for the extravariation associated with correlated data where multiple sites are used from a given subject in any 1 examination. Without accounting for correlated data, the variance estimates and the resulting P values, as reported, may be inaccurate. Another limitation is the absence of adjustment for multiple comparisons where measurements of outcome variables for the test and control sites are compared at each pair of successive surveys (6 comparisons). Finally, the analyses do not include adjustment for variables like age or smoking that might modify or confound the periodontal tissue changes observed. These limitations in the statistical analyses presented in this report make this reviewer hesitant to accept the statistical significance of the conclusions reached by the authors.
Kevin G. Murphy, DDS, MS, Baltimore, Md George W.Taylor, DMD, DrPH, University of Michigan, Ann Arbor Schätzle et al 187