Reports & Studies

Mucositis & gingivitis – are they comparable?

PD Dr. Kristina Bertl, PhD MSc MBA

Unfortunately, peri-implant diseases are an all too common part of our day-to-day work nowadays. Similar to gingivitis and periodontitis, the primary aetiological factor for developing peri-implant mucositis and peri-implantitis is the accumulation of oral biofilm. But how do the tissues respond to this bacterial load? Does the immune system also respond in a similar way?

‘Experimental gingivitis in man’ by Löe, Theilade & Jensen (Aarhus University, Denmark), published in 1965, is possibly one of the most quoted studies in dentistry. A research group from Bern (Switzerland) adapted this study design for implants and tested a direct comparison with natural dentition. This allowed the authors to determine whether tissues around natural teeth and implants respond in a similar way to bacterial contamination or if there are any differences (Salvi et al. 2012).

In total, 15 participants with a healthy periodontal and peri-implant condition took part in this study. The study subjects were asked to forgo all oral hygiene for 3 weeks, before then instituting the best possible oral hygiene for 3 weeks. Clinical parameters and inflammatory parameters were recorded once per week.

As in the study by Löe et al., plaque and bleeding indices increased significantly over the course of the first 3 weeks. Interestingly, however, implants exhibited a higher increase in bleeding index than natural teeth, and the decrease in bleeding index after the resumption of oral hygiene also took longer or was smaller. In addition, an important inflammation parameter (matrix metalloproteinase-8) was also significantly higher for implant-supported restorations than for natural teeth.

Thus, the authors’ conclusions were as follows: under a comparable bacterial load, implants showed a stronger inflammatory response than natural teeth, and this response took longer to heal.


  1. Löe H, Theilade E, Jensen SB. Experimental Gingivitis In Man. J Periodontol. 1965 May-Jun;36:177-87. Salvi GE, Aglietta M, Eick S, Sculean A, Lang NP & Ramseier CA. Reversibility of experimental peri-implant mucositis compared with experimental gingivitis in humans. Clin Oral Impl Res. 23, 2012;182–190. doi: 10.1111/j.1600-0501.2011.02220.x