Objectives: Biofilms contamination of implant surfaces are part of the aetiology of peri-implantitis, and different surface decontamination techniques have been proposed as anti-infective therapy. However, no single intervention has been found to be superior. The focus of the present study was to explore the microbial ecology of the peri-implantitis microcosm, and to develop novel surface decontamination methods. Methods: Microcosm biofilms were grown for 30 days in a constant depth film fermenter (CDFF) on SLA andmTi discs, under standardised parameters associated with peri-implantitis. The discs were randomly allocated to three test groups (T1, T2, T3), and two control groups, one consisting of discs with undisturbed peri-implantitis microcosm biofilms (MC) and one with sterile discs (SC). The test group T1 underwent mechanical cleaning with a TiBrushTM (TiB); T2 underwent a combination of TiB and photodynamic therapy (PDT); and T3 underwent a combination of TiB and 0.2% chlorhexidine gluconate/1% sodium hypochlorate (CA). The biofilms were visualised under confocal laser scanning microscopy and surface chemistry was evaluated by scanning electron microscopy with energy dispersive x-ray analysis (SEM/EDX) and X-ray photoelectron spectroscopy (XPS). The bacterial composition of the biofilms was studied before and after disinfection by next-generation sequencing (NGS) of 16S rRNA gene amplicons (MiSeq). Cytocompatibility testing was carried out using AdB Serotech and endotoxin testing bacterial by Kinetic-QCL. Image J and CasaXPS were used for image analysis. Results: The CDFF peri-implantitis model presented here favoured the growth of higher proportions of Klebsiella, Prevotella, Parvimonas, Porphyromonadaceae (family), Actinomyces, Fusobacterium, Enterobacteriaceae (family), Lachno anaerobaculum and Corynebacterium in in vitro peri-implantitis conditions. ISO-surface-volume rendering and analysis of the confocal biofilm stacks revealed the complex microstructure of the undisturbed MC. The physicochemical composition of titanium surfaces before and after decontamination was also investigated, as well as the biocompatibility effect when cultured with MG-63 cells. Elemental analysis disclosed surface alterations of the discs undergoing different treatments. Endotoxin was found in MC and all test groups. The highest levels were found in M surfaces (MC: 12,000 UI/mL). The core microbiome differed between M and SLA surfaces. Bacteria were observed in all groups after disinfection. Streptococcus were present in all SLA- and M-treated samples. Overall, M surfaces were contaminated by Prevotella, Parvimonas, Klebsiella and Neisseria in the highest proportions. Conclusion: The CDFF is useful for modelling microbial shifts associated with peri-implantitis pathogen communities. It seems that the titanium substrata plays only a minor role in the development of mature biofilms. Our data suggest that no treatment modality hindered biocompatibility of the titanium surface. The bacteria were mainly composed of gram-negative species and Streptococcus, which prevailed after chemical and mechanical therapy and LPS was found in all experimental groups. Collectively, these results suggest that a successful treatment for peri-implantitis should be holistic, eliminating live bacteria and bacterial virulence factors, and take account of alterations in the titanium surface. The state of the titanium oxide layer following disinfection and host interactions biofilms warrant further investigation.

Objectives: The aim of the study was to report two clinical cases of HIV-positive patients on highly active anti-retroviral therapy (HAART) who received implant-supported rehabilitation after bone reconstruction procedures and were followed for up to 10 years. Methods: Case 1 was a 44-year-old women who was referred to treatment because of persistent symptomatic apical periodontitis in elements #30 and #29. During exploratory endodontic surgery, in an attempt to retain her teeth, a longitudinal fracture and extensive bone dehiscence were detected in #29 and replacement by dental implant was planned. Viral load was undetectable and CD4/CD8 counts were compatible with an immunocompetent condition. In a second event, tooth #29 was extracted and the large bone defect filled with a mixture of autogenous bone plus bovine hydroxyapatite. A collagen membrane was used as a barrier. The implant was placed, and after the osseointegration period a metal–ceramic crown was installed. The 10-year follow-up appointment and control x-rays showed healthy and stable peri-implant tissues. Case 2 was a 47-year-old man who was referred for replacement of an upper molar with severe bone loss and close relation with the pneumatised sinus. He had been on HAART for approximately 8 years. Viral load was undetectable and the patient was considered able the receive the intervention. The tooth was extracted and socket preservation techniques were used (bone substitute plus collagen membrane). After healing, a sinus lift procedure was performed with the lateral window technique, using bovine hydroxyapatite and collagen membrane. The implant was placed at the same time. The patient healed uneventfully and has been followed for 8 years with good results. Results: Both HIV-positive patients undergoing HAART had undetectable viral loads and white cell counts (CD4/CD8) within a range that is compatible with dental interventions. Both received antibiotic cover with amoxicillin 500mg and clavulanic acid 125mg three times daily for one week to prevent postoperative infection. They were prescribed ibuprofen 600mg three times daily to control postoperative discomfort. Both patients were followed by an assistant physician who allowed them to undergo the planned dental intervention. All the interventions healed uneventfully and both patients were able to receive the prosthesis within the planned treatment period. At biannual follow-up in a periodontal maintenance program, implants were functional, without clinical or radiographic signs of peri-implantitis or mucositis. The patients maintained satisfying levels of oral hygiene and did reported no significant systemic alterations. Both had undetectable viral loads and good CD4/CD8 counts. Conclusion: HIV-positive patients undergoing HAART are usually able to maintain good systemic conditions and therefore may be eligible to receive implant-supported restorations. In both cases presented, follow-up showed stable and healthy peri-implant tissues and functional implants. Literature on this topic is still restricted to few studies with small samples, but previously published data suggest that well-controlled HIV-positive patients can benefit from dental implants, even when bone augmentation procedures are needed. The need for antibiotic coverage is still controversial.

Ergebnisse des 10. Europäischen Workshops für Parodontologie: Plastische Parodontalchirurgie und Weichgewebsregeneration (10.–13. November 2013, La Granja de San Ildefonso, Spanien) Der 10. Europäische Workshop für Parodontologie wurde gemeinschaftlich organisiert von der European Federation of Periodontology (EFP) und der Osteology Foundation. Deutsche Übsetzung der Publikation im Journal of Clinical Periodontology