N L Y A L S O N F E S SI O O R T A L P N E D PUBLISHED IN DUBAI www.dental-tribune.me March-April 2020 | No. 2, Vol. 10 Peri-implant bone regeneration through laser decontamination Endoscopic paracrestal tunnel technique By Prof. Wilfried Engelke, Dr Chris- tian Engelke, Germany; Dr Victor Beltrán, Chile & Dr Marcio Lazzarini, Germany Introduction The recently published S3 guidelines of the German Association of Oral Implantology (DGI) and the German Society of Dentistry and Oral Medi- cine (DGZMK) state that peri-im- plant infections can be categorised into periimplant mucositis and peri- implantitis.1 In peri-implant mucosi- tis, only the supracrestal soft-tissue interface is involved; in peri-implan- titis, the bony implant site is also involved.2 Smoking is the main risk factor for peri-implant mucositis, but it is likely that there are further contributing factors, such as cement residue, diabetes mellitus and sex.2 The development of peri-implantitis is particularly favoured by a history of periodontal disease, smoking and interleukin-1 polymorphism.4, 5 The main diagnostic criterion for dis- tinguishing peri-implantitis from peri-implant mucositis is the lack of reversibility of the condition. Peri- implantitis can be characterised by putrid secretion, increasing probing depth, pain and radiographic bone resorption. Implant loosening re- quires a high degree of bone resorp- tion in the case of peri-implantitis. Microbiological tests are rather un- specific regarding peri-implant mu- cositis and peri-implantitis. The goal of non-surgical peri-im- plantitis therapy is to eliminate the clinical signs of the infection. In ad- dition to a partial or complete reduc- tion in bleeding on probing (BOP), an effective therapy should lead to a re- duction in the depth of periodontal pockets.6 To date, deep peri-implant pockets have not been clearly de- fined, but in most cases, a probing depth of less than 6 mm is consid- ered a treatment success.7 There are various treatment protocols used for non-surgical therapy: procedures for biofilm removal, antiseptic therapy and adjuvant antibiotic therapy. Surgical peri-implantitis treatment includes surface decontamination, adjuvant resectional therapy and, if necessary, adjuvant augmentative therapy. Surface decontamination by means of a modified ultrasonic system (hydroxyapatite suspen- sion) led to a comparable reduction in mucosal bleeding and probing depth after six months to mechani- cal debridement using carbon fibre or titanium curettes.8 After an ob- servation period of 12 months, BOP values increased again, especially in initially deep pockets.9 In con- ventional flap surgery for surface decontamination, the use of special decontamination methods (e.g. 980 Fig. 1a: Open surgical peri-implantitis therapy with basal stemmed flap: application and operating direction of the laser for sulcular decontamination (yellow), implant surface decontamination (blue) and bone decontamination (white). nm diode laser, carbon dioxide la- ser, chlorhexidine digluconate and cetylpyridinium chloride) did not lead to significantly better clinical or radiographic results than in the re- spective control groups, in which air polishing, chlorhexidine solutions and placebo solutions were used.10, 11 The clinical effectiveness of an ad- juvant augmentative measure for flap surgery alone (titanium curettes and surface conditioning with 24 % ethylenediaminetetraacetic acid and covered wound healing for six months) was investigated in a pro- spective clinical study using a po- rous titanium granulate for treating intraosseous defect components.12 After the primarily covered wound healing, a very high exposure rate was observed in both groups (control group: 12/16; test group: 13/16). After 12 months, both procedures showed a comparable reduction in probing depth and only minor improve- ments in peri-implant bleeding values. However, in the test group, a significantly higher decrease in radiographic translucency in the intraosseous defect area, as well as an increase in implant stability, was observed.12 For advanced, complex defect configurations, surgical aug- mentative and resectional proce- dures were combined as part of an implantoplasty procedure. An im- plantoplasty was aimed at smooth- ing the macro- and microstructure of the implant body in areas outside the physiological barrier of current augmentation procedures. Augmen- tation (xenogeneic bone substitute material of bovine origin and a bar- rier membrane) was carried out only in the area of intraosseous defects, whereby the adjacent implant sur- faces were preserved in their original structure, and these surfaces were decontaminated before augmenta- tion. Over an observation period of four years, combination therapy af- ter open wound healing led to a clini- cally relevant reduction in BOP and ST values. A difference between the two investigated decontamination methods was not observed.13 In summary, it is not possible at this point to clearly determine which protocol should be preferred, based on current literature. In the case of surgical therapy, granulation tissue should first be entirely removed. The decontamination of exposed implant surfaces should be of central importance. Mechanical procedures (for reducing biofilm) and chemical procedures (for reducing and inacti- vating biofilm) are often combined. At this point in time, the additional benefit of peri- and/or postopera- tive antibiotic therapy cannot be as- sessed. Analogous to the guideline for perioperative antibiotic prophy- laxis, a supportive once-off adminis- tration can be done as part of surgical peri-implantitis therapy. After de- contamination, augmentative meas- ures can lead to a radiographically detectable filling of intraosseous de- fect components. It should be noted that all surgical therapy approaches involve a high risk of postoperative mucosal recession. Soft-tissue aug- mentation can be performed to sta- bilise the peri-implant mucosa.14 In addition to these general expla- nations based on the guidelines, a number of techniques have been described that could support mod- ern peri-implantitis treatment based on a minimally invasive therapy concept, given that their concepts can be combined in order to safely decontaminate the implant surface. Kim et al. made a small labial inci- sion with subperiosteal tunnelling for horizontal ridge augmentation.15 They used bone grafts, which were placed in the soft-tissue pocket cre- ated by tunnelling and subsequently fixed by conventional means so that they could successfully integrate im- plants into the alveolar ridge in the context of a two-stage procedure.15 Montevecchi et al. reported cases of peri-implantitis in which fibres of dental floss attached themselves to the implant superstructure and, as a result, gave rise to peri-implantitis.16 They were able to remove these fi- bres using a periodontal endoscopic technique and, in doing so, promote healing. The healing was confirmed over a six-year period. An endoscopi- cally supported therapy in implant dentistry was described by our work- ing group for implant cavities and for sinus floor augmentation in a closed procedure.17, 18 In this context, a tunnel technique was carried out laterally for the augmentation of the sinus floor, in which the entire basal maxillary sinus mucosa was detached and tunnelled through without having to cut a bony win- dow, which made the procedure less invasive. In 2003, Sennhenn-Kirchner and Engelke reported on a procedure in which peri-implantitis can be successfully treated by endoscopic tunnelling and the use of a diode laser.19 The laser is used for decon- taminating the exposed implant surfaces, followed by augmentation of the peri-implant bone defects.19 The authors found that radiographic defect filling and a reduction in prob- ing depths can be achieved, with no postoperative infections and no aug- mentation losses observed in five pa- tients with eight implants.19 Prior to the operation which their research is based on, the probing depths were deeper than 6 mm and, afterwards, between 3 and 4 mm.19 Sennhenn- Kirchner and Engelke emphasised the satisfaction of the patients owing to the minimally invasive nature of the procedure.19 However, there has not been a good solution, thus, far to the problem of accessing contami- nated and infected implants, since ÿPage C2