Background

Periodontitis (gum disease) is a chronic condition caused by bacteria, which stimulate inflammation and destruction of the bone and gum tissue supporting teeth. People treated for periodontitis can reduce the probability of re-infection and disease progression through regular supportive periodontal therapy (SPT). SPT starts once periodontitis has been treated satisfactorily, meaning that inflammation has been controlled and destruction of tissues supporting the tooth (bone and gums) has been arrested. SPT aims to maintain teeth in function, without pain, excessive mobility or persistent infection over the long term. SPT treatment typically includes ensuring excellent oral hygiene, frequent monitoring for progression or recurrence of disease, and removal of microbial deposits by dental professionals. Although success of SPT has been suggested through a number of long-term, retrospective studies, it is important to consider evidence available from randomised controlled trials (RCTs).

Review question

This review explored the effects of different SPT approaches in adults previously treated for periodontitis.

Study characteristics

We searched the medical and dental literature up to 8 May 2017. We found four relevant studies known as randomised controlled trials (RCTs), with 307 participants aged 31 to 85 years. All participants had previously been treated for moderate to severe chronic periodontitis and enrolled in a SPT programme for at least three months. Studies evaluated participants for at least 12 months after starting their SPT programme.

The studies compared: additional use of an antibiotic (doxycycline in one study, minocycline in another) to professional cleaning (debridement); additional use of photodynamic therapy to debridement only, and SPT provided by a specialist versus a general dentist. We did not identify any RCTs comparing the effects of providing SPT versus monitoring only, the effects of SPT provided at different time intervals or the effects of mechanical debridement using different approaches or technologies.

None of the studies reported tooth loss. However, studies evaluated signs of inflammation and potential periodontal disease progression, including bleeding on probing, clinical attachment level and probing pocket depth.

Key results

The very limited amount of evidence did not provide evidence of one approach being better than another to improve tooth maintenance during SPT. Low- to very low-quality evidence suggests that adjunctive treatments may not provide any additional benefit for SPT compared with mechanical debridement alone. Evidence of very low quality suggests that SPT performed by general dentists under specialised prescription may be as effective as specialised treatment. Overall, there is not enough evidence available to recommend a certain approach or additional treatment in SPT to maintain teeth, promote gum health and prevent relapse.

Quality of the evidence

There were only four small studies, and only one of them was at low risk of bias. We judged the evidence to be of low or very low quality, therefore we cannot be confident in any conclusions drawn from the studies’ results.

Authors’ conclusions

We found insufficient evidence about the best approaches to SPT, and no RCTs evaluated SPT versus monitoring only. The evidence we found was low to very low quality, and studies used different methods to report their results, making comparison difficult. More studies are needed that report their findings in a uniform manner.