Risk factors for periodontitis & peri-implantitis.

Risk is part of all health professions and generally indicates the chance of getting some form of illness. For dental practitioners this includes periodontitis or peri-implantitis, the focus of this issue. Many risk factors are involved in the development of disease and most likely interact or overlap. Most patients will probably have multiple risk factors, some of which will be the same for both periodontitis and peri-implantitis. The most recent classification of periodontal disease recognises the importance of risk factors and contemporary dental practice requires that clinicians be aware of and manage them. Broadly speaking risk factors can be patient, environment or practitioner related. Patient risk factors would include socio-economic status, smoking, substance use disorders, diabetes, diet and dietary supplements, mental health disorders, old age, poor home dental care or understanding of the need for good home care and use of medications. Environmental modification of the host response through gene function is an emerging risk factor. Lastly, practitioner-related factors in implant dentistry are now known to affect risk. These would include the use of digital technology, but patient related factors such implant location and the body's reaction to an implant itself add to the risk of developing disease. This edition of Periodontology provides an uptodate review of many of these risk factors and their impact summarising current knowledge.

Into the Paradigm of Local Factors as Contributors for Peri-implant Disease: Short Communication.

Although some systemic conditions have been associated with peri-implant disease, local contributing factors largely remain to be determined. This study aimed at evaluating, based on clinical photographs obtained from peri-implantitis treatment publications, the possible local contributing factors involved in its development based upon a survey obtained from three experienced clinicians (> 20 years of expertise). Cohen's kappa index was used to test the interexaminer reliability. "Too-buccal implant position" was the only parameter to reach almost perfect interexaminer agreement (κ = 0.81). "Thin-tissue biotype" and "minimal presence of keratinized mucosa" demonstrated moderate agreement (κ = 0.43 and κ = 0.58, respectively). The rest of the parameters studied based on clinical photographs were fair or poor. Therefore, based on this clinicians' survey, implants too buccally placed, minimal or a lack of keratinized mucosa, and thin-tissue biotype might contribute to a higher susceptibility of developing peri-implantitis. These factors must be the focus of attention in future cross-sectional studies on the incidence of peri-implant diseases.

Thermodynamic effects of laser irradiation of implants placed in bone: an in vitro study.

Lasers have been proposed for various applications involving dental implants, including uncovering implants and treating peri-implantitis. However, the effect of laser irradiation on the implant surface temperature is only partially known. The aim of this pilot study was to determine the effect of irradiation with diode, carbon dioxide, and Er:YAG lasers on the surface temperature of dental implants placed in bone, in vitro. For this study, one dental implant was placed in a bovine rib. A trephine bur was used to create a circumferential defect to simulate peri-implantitis, and thermocouples were placed at the coronal and apical aspect of the implant. The implant was irradiated for 60 s using four different lasers independently and change in temperature as well as time to reach a 10 °C increase in temperature were recorded. There was wide variability in results among the lasers and settings. Time for a 10 °C increase ranged from 0.9 to over 60 s for the coronal thermocouple and from 18 to over 60 s for the apical thermocouple. Maximum temperature ranged from 5.9 to 70.9 °C coronally and from 1.4 to 23.4 °C apically. During laser irradiation of dental implants, a surface temperature increase beyond the "critical threshold" of 10 °C can be reached after only 18 s.

Gene expression of inflammation and bone healing in peri-implant crevicular fluid after placement and loading of dental implants. A kinetic clinical pilot study using quantitative real-time PCR.

PURPOSE: Early detection of healing complications after placement of dental implants is a pressing but elusive goal. This paper proposes a non-invasive diagnostic tool for monitoring healing- and peri-implant disease specific genes, complementary to clinical evaluations. MATERIAL AND METHODS: Eighteen partially edentulous patients were recruited to this pilot study. Three Brånemark TiUnite® implants/patient (Nobel Biocare) were placed in a one-stage procedure. Abutments with smooth or rough (TiUnite®) surface were placed. The test group (n = 9) received fixed bridges (immediate loading), whereas the control group (n = 9) implants were loaded 3 months after surgery. In addition to clinical measurements, crevicular fluid was collected using paper strips at the implant abutments 2, 14, 28, and 90 days postoperative. mRNA was extracted, purified, and converted to cDNA. Quantitative PCR assays for IL-1ß, TNF-α, Osteocalcin (OC), Alkaline Phosphatase (ALP), Cathepsin K, Tartrate Resistant Acid Phosphatase, and 18S ribosomal RNA were designed and validated. Relative gene expression levels were calculated. RESULTS: One implant was lost in the control group and three in the test group. In one test patient, one implant showed lowered stability after 2 to 4 weeks and was unloaded. Later implant stability improved which allowed for loading after 3 to 4 months. TNF-α and ALP most commonly showed correlation with clinical parameters followed by IL-1ß and OC. The strongest correlation was found for TNF-α with clinical complications at 2 and 14 days (p = .01/r = -048, and p = .0004/r = -0.56, respectively; test and control groups together). In some cases, gene expression predicted clinical complications (TNF-α, ALP, CK). CONCLUSION: This study is based on samples from few individuals; still, some genes showed correlation with clinical findings. Further studies are needed to refine and optimize the sampling process, to find the appropriate panel, and to validate gene expression for monitoring implant healing.

Oral rehabilitation with dental implants after cancer treatment.

BACKGROUND: Patients who undergo surgical management of oral cancer may greatly benefit from an implant-supported prosthesis. This study reports on the clinical experience of dental implant placement in patients following resection of oral cancer over a 15-year period. Controversies including the use of dental implants in irradiated tissues, and hyperbaric oxygen treatment will also be discussed. METHODS: Thirty-one patients who had dental implants placed as part of their oral rehabilitation between 1992 and 2007 were investigated. Demographic data and factors including implant survival, type of prosthesis provided, radiotherapy and the hyperbaric oxygen therapy were analysed. RESULTS: In this retrospective study, there was a retention rate of 110 implants from a total of 115 implants placed. A high rate of implant retention was found, with 5 implant failures from a total of 115 implants placed. The 5 failed implants occurred in free flap bone that had been irradiated. CONCLUSIONS: Dental implants provide an important role in the oral rehabilitation of oral cancer patients. There may be an increased risk of implant failure in free flap bone that has been irradiated.