Perio treatment may lower risk of preterm birth

A new systematic review has found that pregnant women who are at high risk for preterm birth and have periodontal disease may be able to lower their risk by getting scaling and root planing (SRP) treatment (Journal of Periodontology, December 2012, Vol. 83:12, pp. 1508-1519).

While previous studies have shown an association between preterm labor and periodontitis in pregnant women, the relationship is still under investigation, and a link has not been clearly established, noted the study authors, from the Harvard School of Dental Medicine, Dartmouth Medical School, and Dartmouth Institute for Health Policy and Clinical Practice.

If prenatal treatment of periodontitis is effective for preventing prematurity, increased availability of treatment could result in significant healthcare cost savings, they added.

"The connection between periodontitis and general health is of great interest," study author Nadeem Karimbux, DMD, an associate professor in the department of oral medicine, infection, and immunity at the Harvard School of Dental Medicine, told DrBicuspid.com. "A study like this captures all that is known about the topic to date."

Benefits outweigh potential harm

Dr. Karimbux and his colleagues performed a systematic review and meta-analysis of randomized controlled trials to evaluate the efficacy of SRP in reducing preterm birth and the risk of low birth weight. They also analyzed key subgroups and further explored heterogeneity and bias risks in the pooled studies.

They searched the Cochrane Library (from 1990 to September 2011), Medline (from 1950 to September 2011), Cumulative Index to Nursing and Allied Health Literature (CINAHL, from 1980 to September 2011), the University of Michigan School of Dentistry's Dentistry and Oral Sciences database (from 1990 to September 2011), conference proceedings, and the ClinicalTrials.gov database. The final search update was performed on September 19, 2011.

After abstract review, 12 studies were identified by the search, and 11 were included in the main meta-analysis. Overall quality and design of included studies were fair or good.

Selection criteria included randomized controlled trials that reported preterm-birth risk (less than 37 weeks) outcomes, compared SRP treatment to either placebo or no treatment in pregnant patients with periodontitis, and had a probing depth of more than 4 mm or clinical attachment loss greater than 2 mm for one or more sites. Studies followed all participants through delivery or loss of pregnancy. Infant gestational age was a required outcome.

The researchers found that the clinical benefits of treating chronic periodontitis in pregnant women who are at a high risk of preterm delivery outweigh the potential harms.

"Although periodontal treatment is not universally effective, there is little indication of clinically significant harms from treatment or, at least generally, no excessive overall attrition or statistically increased preterm birth in any study," the study authors wrote.

The main implication of these findings is that, for the general population undergoing pregnancy, there is not sufficient evidence to support the need for periodontitis treatment to reduce the risk of preterm birth, they noted.

However, a posthoc subgroup analysis of the study findings indicated a statistically significant association between the treatment of periodontitis and reduction in the risk of preterm birth for groups with high risks of preterm birth, they added.

The fact that women who have other risk factors for preterm or low-birth-weight babies and also have chronic periodontitis can lower that risk by having scaling and root planing is new information that has not been reported before, according to Dr. Karimbux.

"Dentists can use these findings in their everyday practice to educate their pregnant patients, as well as their fellow physicians, and maybe improve the systemic health of some patients," he added.

Additional research

Another recent systematic review that evaluated whether maternal periodontal disease treatment can reduce preterm birth and/or low-birth-weight incidence found that treatment did not decrease risk (Journal of Periodontology, October 2011, Vol. 38:10, pp. 902-914).

Of the 13 randomized controlled trials that provided data, only five were considered to be at a low risk of bias. And although the results of eight studies showed that treatment may reduce risk, the meta-analysis showed contrasting results. The influence of specific aspects such as disease diagnosis, extension and severity, and the success of treatment should be evaluated further, wrote the authors of that study.

Meanwhile, the authors of the current review noted that their analysis indicates a statistically significant effect in reducing risk of preterm birth for SRP in pregnant women with periodontitis for groups with a high risk of preterm birth only.

"Future research should attempt to confirm these findings and further define groups in which risk reduction may be effective," they concluded.