What’s the evidence on the best approach to supportive periodontal therapy?

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).

What was the research?

A systematic review to explore the effects of different SPT approaches in adults previously treated for periodontitis.examine…

Who conducted the research?

The research was conducted by a team led by Carolina Manresa of the Dental School at the University of Barcelona, Spain, on behalf of Cochrane Oral Health. Elena C. Sanz Miralles, Joshua Twigg and Manuel Bravo were also on the team.

What evidence was included in the review?

We included 4 randomised controlled trials, including 307 participants.

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.

What did the evidence say?

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.

How good was 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.

What are the implications for dentists and the general public?

There is no evidence available to determine the merits of supportive periodontal therapy (SPT) versus monitoring alone, or SPT provided at different time intervals. There is a very limited amount of evidence, of low to very low quality, suggesting 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, definitive clinical protocols are still lacking as the evidence is insufficient to draw any reliable conclusions about the equality or superiority of different approaches to SPT.

What should researchers look at in the future?

There is a need for well-conducted trials on SPT in order to answer the four questions that were considered for this systematic review: the effectiveness of SPT compared to monitoring/standard dental care, different timings of SPT, adjuncts to SPT and different approaches for mechanical debridement as part of SPT. Greater attention should be given to the methodology used to assess SPT. Duration of follow-up is of paramount importance when adding adjunctive treatments to SPT, as many adjuncts demonstrate short-term effectiveness but fail to demonstrate long-term improvement in clinical outcomes. Studies should focus on the clinical significance of results, in order to place the effectiveness of adjunctive therapy in perspective. Tooth loss should be considered as an outcome because of its clinical importance. In future, rigorous trials with adequate sample sizes should be planned with a minimum of 12 months’ follow-up, and should also consider patient-orientated outcomes (costs, dentine hypersensitivity, comfort, satisfaction), which are likely to influence adherence to SPT programmes.


Manresa C, Sanz-Miralles EC, Twigg J, Bravo M. Supportive periodontal therapy (SPT) for maintaining the dentition in adults treated for periodontitis. Cochrane Database of Systematic Reviews 2018, Issue 1. Art. No.: CD009376. DOI: 10.1002/14651858.CD009376.pub2.

This post is an extended version of the review’s plain language summary, compiled by Anne Littlewood at the Cochrane Oral Health Editorial Base.