Table 6.

Summary of issues identified by authors of systematic reviews of RCTs

1. Inconsistency in defining periodontal disease and periodontal status 2. Inconsistency in the type of periodontal treatment provided, timing, frequency, clinician 3. Quality of studies (methodological shortcomings): low quality supported a beneficial effect of treatment for PTB & LBW (high heterogeneity); overestimated treatment effect high quality provided clear evidence that no effect of treatment exists 4. Publication bias: studies showing no/negative effect may not have been published 5. Evidence does not support SRP for reducing the rate of PTB 6. Gingivitis and periodontitis in the same meta-analysis; questionable 7. Treatment effectiveness should be measured 8. Selection criteria: high-risk & low-risk individuals combined; taking medication and other dental treatment not reported 9. Is SRP the preferred treatment (vs. mouth wash or antibiotics)? 10. Other conditions, e.g., smoking, not reported or evaluated