Does the Non-surgical Application of Enamel Matrix Derivative Reduce the Need of Periodontal Surgical Intervention in Subjects With Severe (Stage III) Periodontitis? A Randomized, Multicenter, Clinical Trial

Periodontal treatment relies on a sequential series of different phases that are usually incapsulated in three main phases: non-surgical treatment, surgical phase and, finally, supportive phase. Whilst, on the one hand not all patients may undergo surgical interventions, on the other hand non-surgical periodontal and supportive treatment are administered to all subjects affected by periodontitis. Both phases are constituted by closed, non-surgical, root instrumentation which is often carried out with similar techniques. Thus, non-surgical periodontal treatment (NSPT) is the one key stone of the treatment of periodontitis.

NSPT is very efficacious. A significant majority of the diseased sites are usually managed non-surgically (Graziani et al., 2017)). Moreover, bleeding on probing and symptoms are significantly decreased by NSPT. Importantly, NSPT is also capable to reduce systemic inflammation (Teeuw et al., 2014), improve glycaemic control (Sanz et al., 2018) and overall ameliorate oral health related quality of life (Graziani, Music, et al., 2019). Lastly, NSPT is cost effective as its costs are moderate and it may be performed by both dentists and hygienists.

Nevertheless, NSPT is often uncapable to solve an entire clinical case and surgical treatment is advocated as in fact the complete closure of the pockets ranges from 57 to 75% according to a follow-up of 3⁄4 months or 6/8 respectively (Solini et al., 2019). Periodontal surgery is also effective, but it is nonetheless a surgical intervention which cannot be defined as deprived of side effects (Graziani et al., 2018).

Thus, in order to improve the outcome of NSPT numerous adjunctive treatment modalities have been advocated (Braun et al., 2008; Graziani et al., 2017; Haffajee et al., 2003). Yet the objective of reducing the need for surgery has been rarely evaluated.

Recently, our group ran a trial in which enamel matrix derivatives (EMD) has been applied as non-surgical adjunct. The findings highlighted that EMD application lowers systemic inflammation, increases blood clot stability and, locally, reduces of the need for surgery by 32% compared to the control group without EMD.

Thus, a multicentre responding to the following questions:

• Flapless application of EMD reduce the need for periodontal surgery?
• Are the results stable over time?
• Can the results be generalized among different clinicians? EMD is a resorbable, implantable material and supports periodontal regeneration, which takes place over more than a year. It consists of hydrophobic enamel matrix proteins extracted from developing embryonal enamel of porcine origin in a propylene glycol alginate carrier.

The gel has a suitable viscosity to facilitate application directly onto root surfaces exposed during periodontal surgery. Once applied onto an exposed root surface the protein self assembles into an insoluble three-dimensional matrix and creates a suitable environment for selective periodontal cell migration and attachment, which re-establishes lost tooth supporting tissues. Subsequent to formation of new attachment, alveolar bone can also be regenerated due to the osteogenic capacity of the restored periodontal ligament. EMD is degraded by enzymatic processes of normal wound healing.