Non-surgical treatment of peri-implant mucositis and peri-implantitis at zirconia implants: a prospective case series.

OBJECTIVES: To assess the efficacy of non-surgical therapy for the management of peri-implant diseases at a two-piece zirconium implant system. MATERIAL & METHODS: Thirty-four patients with 45 implants participated in this study. Seventeen patients (24 implants) were diagnosed with peri-implant mucositis and received mechanical debridement + local antiseptic therapy using chlorhexidine digluconate (MD + CXH), while 17 patients (21 implants) diagnosed with peri-implantitis were assigned to Er:YAG laser therapy. In both groups, post-operative maintenance care included supramucosal plaque removal and local pocket irrigation using CHX. The primary endpoint was defined as disease resolution at 6 months (i.e. absence of bleeding upon probing (BOP) at mucositis sites/absence of BOP and probing pocket depths (PD) ≥6 mm at peri-implantitis sites). RESULTS: Resolution of peri-implant mucositis and peri-implantitis was obtained in 9/17 (52.9%) (p = 0.001) and 5/17 (29.4%) (p = 0.02) of the patients respectively. CONCLUSION: Non-surgical treatment of either peri-implant mucositis using MD + CHX or peri-implantitis using ERL at zirconia implants was associated with significant short-term clinical improvements. A complete disease resolution, however, was not achieved in the majority of the patients.

Real-time PCR analysis of fungal organisms and bacterial species at peri-implantitis sites.

BACKGROUND: The potential role of fungal organisms and their co-aggregation with either periodontopathogens or opportunistic pathogens at peri-implantitis sites is unknown. The aim of the present study was to qualitatively/quantitatively analyze and correlate fungal organisms and bacterial species at peri-implantitis sites. METHODS: In a total of 29 patients, submucosal/subgingival plaque samples were collected at peri-implantitis and healthy implant sites as well as teeth with a history of periodontitis (controls). A real-time PCR assay was established for the qualification of fungal organisms and a TaqMan assay for the quantification of Porphyromonas gingivalis, Parvimonas micra, Tannerella forsythia, Mycoplasma salivarium, Veillonella parvula, and Staphylococcus aureus. RESULTS: Fungal organisms were more frequently identified at peri-implantitis (31.6%) (i.e., Candida albicans, Candida boidinii, Penicillium spp., Rhodotorula laryngis, Paelicomyces spp., Saccharomycetes, Cladosporium cladosporioides) and healthy implant sites (40% - Candida dubliniensis, C. cladosporioides) than at selected teeth (20% - C. albicans, Fusarium solani). At implant sites, fungal organisms were significantly correlated with P. micra and T. forsythia. CONCLUSIONS: Candida spp. and other fungal organisms were frequently identified at peri-implantitis as well as healthy implant sites and co-colonized with P. micra and T. forsythia.

Impact of implant-abutment connection and positioning of the machined collar/microgap on crestal bone level changes: a systematic review.

OBJECTIVES: To address the following focused question: What is the impact of implant-abutment configuration and the positioning of the machined collar/microgap on crestal bone level changes? MATERIAL AND METHODS: Electronic databases of the PubMed and the Web of Knowledge were searched for animal and human studies reporting on histological/radiological crestal bone level changes (CBL) at nonsubmerged one-/two-piece implants (placed in healed ridges) exhibiting different abutment configurations, positioning of the machined collar/microgap (between 1992 and November 2012: n = 318 titles). Quality assessment of selected full-text articles was performed according to the ARRIVE and CONSORT statement guidelines. RESULTS: A total of 13 publications (risk of bias: high) were eligible for the review. The weighted mean difference (WMD) (95% CI) between machined collars placed either above or below the bone crest amounted to 0.835 mm favoring an epicrestal positioning of the rough/smooth border (P < 0.001) (P-value for heterogeneity: 0.885, I2: 0.000% = no heterogeneity). WMD (95% CI) between microgaps placed either at or below the bone crest amounted to -0.479 mm favoring a subcrestal position of the implant neck (P < 0.001) (P-value for heterogeneity: 0.333, I2: 12.404% = low heterogeneity). Only two studies compared different implant-abutment configurations. Due to a high heterogeneity, a meta-analysis was not feasible. CONCLUSIONS: While the positioning of the machined neck and microgap may limit crestal bone level changes at nonsubmerged implants, the impact of the implant-abutment connection lacks documentation.

Long-term follow-up of simultaneous guided bone regeneration using native and cross-linked collagen membranes over 6 years.

OBJECTIVES: To investigate the impact of a cross-linked- (VN) collagen membrane on the long-term stability of peri-implant health over 6 years. MATERIAL AND METHODS: Vestibular dehiscence-type defects at titanium implants (19 patients, 19 implants) were augmented using a natural bone mineral and randomly allocated to either VN or a native collagen membrane (CM) and left to heal in a submerged position for 4 months. Clinical parameters (i.e. Bleeding on Probing-BOP, probing pocket depth-PD, mucosal recession-MR) were recorded at 4 and 6 years after prosthesis installation. RESULTS: At 4 and 6 years, both VN and CM revealed comparable mean BOP, PD and MR values at both vestibular and oral aspects. Changes in these parameters from 4 to 6 years were minimal (vestibular aspect-VN: -3.3 ± 48.2%, -0.1 ± 0.5 mm, -0.1 ± 0.3 mm; CM: -1.8 ± 33.7%, 0.0 ± 0.4 mm, -0.1 ± 0.7 mm) and not significantly different between groups. At 6 years, the incidence of mucositis and peri-implantitis was comparable in both groups (VN: 60.0% and 20.0%; CM: 33.3% and 33.3%). CONCLUSION: In conclusion, the present follow-up observation failed to identify any beneficial impact of VN over CM on peri-implant health at 4 and 6 years.

Four-year follow-up of combined surgical therapy of advanced peri-implantitis evaluating two methods of surface decontamination.

OBJECTIVES: To investigate the impact of two surface decontamination methods on the long-term outcomes following combined surgical resective/regenerative therapy of advanced peri-implantitis lesions. MATERIAL AND METHODS: Seventeen patients (n = 17 combined supra- and intrabony-defects) completed the 48 months follow-up observation following access flap surgery, granulation tissue removal and implantoplasty at bucally and supracrestally exposed implant parts. The remaining unmodified implant surface areas were randomly treated using either (i) an Er:YAG laser (ERL), or (ii) plastic curets + cotton pellets + sterile saline (CPS), and augmented with a natural bone mineral + collagen membrane. RESULTS: At 48 months, CPS-treated sites tended to reveal higher reductions in mean BOP (CPS: 85.2 ± 16.4% versus ERL: 71.6 ± 24.9%) and CAL values (CPS: 1.5 ± 2.0 mm versus ERL: 1.2 ± 2.0 mm) when compared with the ERL group. In both groups, clinical outcomes were not directly influenced by the initial defect configuration. CONCLUSION: The 4-year clinical outcomes obtained following combined surgical resective/regenerative therapy of advanced peri-implantitis were not influenced by the method of surface decontamination.

Influence of two barrier membranes on staged guided bone regeneration and osseointegration of titanium implants in dogs: part 1. Augmentation using bone graft substitutes and autogenous bone.

OBJECTIVES: To assess the influence of two barrier membranes and two bone graft substitutes mixed with autogenous bone (AB) on staged guided bone regeneration and osseointegration of titanium implants in dogs. MATERIALS AND METHODS: Four saddle-type defects each were prepared in the upper jaw of six fox hounds and randomly filled with a natural bone mineral (NBM)+AB and a biphasic calcium phosphate (SBC)+AB and allocated to either an in situ gelling polyethylene glycol (PEG) or a collagen membrane (CM). At 8 weeks, modSLA titanium implants were inserted and left to heal in a submerged position. At 8+2 weeks, dissected blocks were processed for histomorphometrical analysis (e.g., treated area [TA], bone-to-implant contact [BIC]). RESULTS: The mean TA values (mm(2) ) and BIC values (%) tended to be higher in the PEG groups(TA: NBM+AB [10.4 ± 2.5]; SBC+AB [10.4 ± 5.8]/BIC: NBM+AB [86.4 ± 20.1]; SBC+AB [80.1 ± 21.5]) when compared with the corresponding CM groups (TA: NBM+AB [9.7 ± 4.8]; SBC+AB [7.8 ± 4.3]/BIC: NBM+AB [71.3 ± 20.8]; SBC+AB [72.4 ± 20.3]). A significant difference was observed for the mean TA values in the SBC+AB groups. CONCLUSION: It was concluded that all augmentation procedures investigated supported bone regeneration and staged osseointegration of modSLA titanium implants. However, the application of PEG may be associated with increased TA values.

Influence of two barrier membranes on staged guided bone regeneration and osseointegration of titanium implants in dogs. Part 2: augmentation using bone graft substitutes.

OBJECTIVES: To assess the influence of two barrier membranes and two bone graft substitutes on staged guided bone regeneration and osseointegration of titanium implants in dogs. MATERIALS AND METHODS: Saddle-type defects were prepared in the lower jaws of 6 fox hounds and randomly filled with a natural bone mineral (NBM) and a biphasic calcium phosphate (SBC) and allocated to either an in situ gelling polyethylene glycol (PEG) or a collagen membrane (CM). At 8 weeks, modSLA titanium implants were inserted and left to heal in a submerged position. At 8+2 weeks, respectively, dissected blocks were processed for histomorphometrical analysis (e.g., mineralized tissue [MT], bone-to-implant contact [BIC]). RESULTS: The mean MT values (mm2) and BIC values (%) tended to be higher in the PEG groups (MT: NBM [3.4±1.7]; SBC [4.2±2]/BIC: NBM [67.7±16.9]; SBC [66.9±17.8]) when compared with the corresponding CM groups (MT: NBM [2.5±0.8]; SBC [2.3±1.6]/BIC: NBM [54.1±22.6]; SBC [61±8.7]). These differences, however, did not reach statistical significance. CONCLUSION: It was concluded that all augmentation procedures investigated supported bone regeneration and staged osseointegration of modSLA titanium implants.