Risks and complications

Biological complications are common in implant therapy: the prevalence of peri-implant mucositis (PM) was recently reported as 43% and peri-implantitis (PI) as 22% (Derks & Tomasi. 2015). It has been reported that patients with peri-implant mucositis, if not treated, have a six times higher risk for peri-implantitis (Costa et al. 2012).

“The prevalence of peri-implant mucositis (PM) was recently reported as 43% and peri-implantitis (PI) as 22%”

A recent systematic review concluded that mechanical plaque control should be considered the standard of care in management of PM (Salvi & Ramseier. 2015). There are a number of adjunctive mechanical/chemical methods for implant surface decontamination, but they do not seem to improve the efficacy of regular debridement. Air polishing devices are simple to use, do not make marked changes in transmucosal implant surfaces and appear equally efficient as other types of instruments used for the mechanical decontamination of implants (Schwarz et al. 2015). Although PM can usually be completely resolved, this should not be expected in all patients, and some cases may evolve into PI.

PI should be addressed surgically, since only non-surgical treatment of PI is not commonly ineffective in disease resolution. The strategic position of the implant and extent of bone loss should be considered in the decision to treat the implant surgically or to remove it. The surgical approach must take into account the morphology and extent of the defect, the type of implant surface, and local and systemic conditions (Figure 1).

“PI should be addressed surgically”

There is no general consensus on which treatment method is more effective. We should therefore rely on consensus from experts (Heitz-Mayfield et al. 2014):

• reducing risk factors is crucial, especially by controlling the patient’s oral hygiene and the design and cleansability of the prosthesis
• non-surgical debridement should be performed before any surgical intervention (for example, air-polishing with a subgingival tip)
• the site should be re-assessed and surgically treated after 3–4 weeks, when less inflammation is usually present
• the aim of surgery is to access the implant surface to decontaminate it, and there are many different combinations of mechanical and chemical methods available. No recommendations for a specific method can be given, as complete biofilm removal appears to be impossible (Ntrouka et al. 2011)
• following decontamination, the practitioner should choose between a resective or regenerative approach. The decision will depend primarily on:
  • the configuration of the bony lesion
  • the type of surface of the implant

Following the classification proposed by F. Schwarz (Schwarz et al. 2007; Schwarz et al. 2010), circumferential bony defects (class Ie) respond better to regenerative therapy than bony defects with some degree of buccal dehiscence (class Ib or class Ic). Horizontal defects (class II) should only be treated by a resective approach, especially in non-aesthetic areas.

A preclinical in vivo study has demonstrated that the type of implant surface affects the treatment outcome of PI (Albouy et al. 2011). This should therefore be taken into account when selecting the proper treatment.

• in cases involving horizontal defects and machined implants, a resective approach should be undertaken
• if implants with a modified surface are being used, implantoplasty should be added to the treatment plan, as it has been shown to minimise the progression of bone loss (Romeo et al. 2005; Romeo et al. 2007)
• in cases where class Ib or Ic bony defects are present, a combined approach is recommended, involving implantoplasty at the aspect of the implant harboring a dehiscence, and regeneration in the intrabony part of the defect (Schwarz. 2013) (Figures 2–3)

The use of adjunctive antibiotics seems to be beneficial in cases involving rough implants, but not in cases involving machined implants treated with a resective approach. It should also be noted that the potential benefits of adjunctive antibiotics on the long-term is not known (Caruac et al. 2017).

“The type of implant surface affects the treatment outcome of PI”

The speaker concluded by saying that bone loss progresses rapidly in peri-implantitis, and therefore treatment must be undertaken quickly to minimise the damage.

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