Joseph Gambacorta DDS; Elizabeth Stellrecht M.L.S.
Scaling and root planing (SRP) treatment for periodontitis can reduce the chance of preterm birth only in high-risk preterm birth groups.
In pregnant women with moderate to severe periodontitis, does the addition of SRP in comparison to just OHI reduce the risk of preterm birth and low birth weight?
A comprehensive search of four databases was conducted from 1950 to September 2011. Hand searches along with a search for unpublished literature via ClinicalTrials.gov and scientific conference abstracts were also completed. No search limits were set. Only randomized controlled trials (RCTs) were included that reported preterm-birth risks in pregnant women with singleton pregnancies, presence of significant periodontal disease treated with SRP, and considered preterm birth (<37 weeks) as primary outcome. Secondary outcomes were alleviation of periodontal disease in the pregnant women, average infant birth weight, and rates of fetal loss. The extent of periodontal intervention was based upon review of probing depths, plaque status, and history of previous dental treatment. Both control and intervention groups could receive routine dental treatment and oral hygiene instruction. Studies were excluded if control groups received active periodontal treatment before delivery, if all participants were not followed through delivery or loss of pregnancy, or if infant gestational age was not an outcome. Four reviewers were involved in the selection process with two additional reviewers involved in case of any discrepancies. A post-hoc analysis of studies sub-grouped based om preterm birth of less than 35 weeks was performed, as well as a similar analysis for studies reporting low birth weight and mean birth weight.
The authors included 12 RCT's with 6229 total participants in the main meta-analysis. One study was eliminated from main analysis because it only reported data based on preterm birth of <35 weeks, but was later included in the secondary, post-hoc analysis. Although all studies met the inclusion criteria, methodological details varied significantly (timing of the intervention, definition of periodontitis case and general prevalence of premature birth). An overall non-significant risk ratio (RR) of 0.81 (95% confidence interval [CI=0.64, 1.02) was calculated for the primary outcome. Relatively similar results were obtained for preterm birth. In a subgroup analysis including only individuals at high overall risk of prematurity, the RR was reduced to a statistically significant 0.66 (95% CI=0.54, 0.80). The authors deemed these individuals as high risk due to the significantly higher percentage of preterm birth found in the populations' respective studies. The remaining RCT's examined (with mild to moderate risk) showed a risk ratio of 0.97 (95% CI=0.75, 1.24). For low birth weight (<2500g) no significant findings were demonstrated. For the overall analysis heterogeneity was large due to differing defined periodontal parameters within the included studies. Subgroup data analysis suggests that in studies where prematurity was excessive (<35 weeks), SRP led to a significant reduction in preterm birth, but not in mean birth weight.
Fair to good evidence shows that SRP periodontal treatment reduces the risk of preterm birth in groups that are high-risk for preterm birth.
Source of Funding:
No sources identified.
Importance and Context:
Periodontal treatment of pregnant women is a highly debated topic in dental care. Previous studies are contradictory in nature, with some concluding that SRP does not affect preterm birth (1). Others state that SRP is beneficial in potentially decreasing the risk of preterm birth (2). Patient engagement, quality of the therapy, diligent home care and follow up appointments are essential contributors to a favourable periodontal prognosis.
Strengths and Weaknesses of the Systematic Review:
Accepted SR execution and reporting guidelines were followed. While inclusion criteria were clearly stated, exclusion criteria were never explicitly specified. The literature search was very comprehensive, as four databases, hand searches of references, and sources of unpublished literature were consulted over an expansive date range. Four reviewers independently screened potential studies, suggesting minimal selection bias. Not all possible periodontal treatment options currently available were considered. The authors determined high risk criteria to be defined as previous preterm births of <35 weeks and low birth weight of <2,500 g, but do not list any other identifiers or symptoms that contribute to high risk pregnancies.
Strengths and Weaknesses of the Evidence:
The included studies had differing definitions of what periodontitis case was. Although some of them were reasonable, it makes the synthesis (meta-analysis) of the available results questionable. A variety of intervention times were proposed. Some of the included studies had relatively small sample sizes. Time frame between SRP and outcome assessment was variable or not clearly reported. In addition, varying degrees of measurements for attachment loss and probing depth do not allow for an adequate comparison of periodontal disease between study populations. Included studies included OHI for all groups, but they did not explain how its effectiveness was assessed. Three studies did not properly address missing data. The authors also determined that some studies had selective reporting and sources of bias. For overall analysis heterogeneity of the included articles was high, making it very difficult to draw well-supported conclusions. For the post hoc subgroup analysis, heterogeneity was more acceptable.
Implications for Dental Practice:
There is still controversy, as shown by several SRs with differing conclusions about the effects of periodontal treatment on pregnant women. This SR with its subgroup analysis considering risk status, adds some additional new information. While primary outcomes of this review showed no correlation between SRP treatment intervention and the reduction of preterm birth and low birth weight, subgroup analysis indicated that in pregnant women at high-risk for preterm delivery with chronic periodontitis, the clinical benefits of treatment may outweigh the potential harms. It is possible that SRP can be an important factor to decrease the associated risks of preterm birth, but this needs to be confirmed with further clinical research. References: 1. Macones GA, Parry S, Nelson DB, et al. Treatment of localized periodontal disease in pregnancy does not reduce the occurrence of preterm birth: results from the Periodontal Infections and Prematurity Study (PIPS). American journal of obstetrics and gynecology. 2// 2010;202(2):147.e141-147.e148. 2. Polyzos NP, Polyzos IP, Mauri D, et al. Effect of periodontal disease treatment during pregnancy on preterm birth incidence: a metaanalysis of randomized trials. American journal of obstetrics and gynecology. 3// 2009;200(3):225-232. 3. Sanz M, Kornman K. Periodontitis and adverse pregnancy outcomes: consensus report of the Joint EFP/AAP Workshop on Periodontitis and Systemic Diseases. Journal of clinical periodontology 2013;40(s14):S164-S69.