Prevalence and treatment of retrograde peri-implantitis: a retrospective cohort study covering a 20-year period.

OBJECTIVES: The aims of this retrospective study were to report data on the prevalence of retrograde peri-implantitis (RPI) in a single-center in a 20-year observation period and to evaluate implant survival after surgical treatment. MATERIALS AND METHODS: A retrospective cohort study was conducted screening all patients who underwent implant treatment in a private practice. Patients were enrolled if they had one or more implants showing a radiolucency around the implant apex, without implant mobility. Furthermore, clinical symptoms of RPI and days from symptoms' appearance after implant placement were also collected, as well as periodontal and endodontic status of nearby teeth. All patients were treated with the same surgical approach: antibiotic therapy, mechanical curettage, chemical decontamination and xenograft application. RESULTS: Out of the 1749 implants placed, only 6 implants were classified as affected by RPI, with a prevalence of 0.34%. Clinical symptoms of RPI (pain, swelling, dull percussion or fistula presence) varied among patients and were reported after a mean period of 51.83 ± 52.43 days. CONCLUSIONS: RPI was successfully treated with surgical curettage and bone substitute application and all implants are still in place after a mean follow-up of 8.83 ± 5.34 years. CLINICAL RELEVANCE: Bacteria from teeth with failed endodontic treatment or residual lesions might be reactivated by drilling for implant osteotomy, with subsequent colonization of the implant apex and possible failure before prosthetic loading. Therefore, it might be recommended to take a periapical x-ray at implant placement and after 6-8 weeks in order to intercept RPI before prostheses delivery.

Evaluation of Highly Porous Dental Implants in Postablative Oral and Maxillofacial Cancer Patients: A Prospective Pilot Clinical Case Series Report.

PURPOSE: The aim of this study was to evaluate the clinical efficacy of new porous tantalum trabecular metal (PTTM)-enhanced titanium dental implants used for the prosthodontic rehabilitation of postablative cancer patients. First-year interim results of a prospective clinical case series are presented. MATERIALS AND METHODS: A total of 25 PTTM-enhanced titanium implants were placed in both maxillas and mandibles of 6 patients, who met specific inclusion criteria. Resonance frequency analysis was conducted, and implant stability was recorded in Implant Stability Quotient (ISQ) values at implant placement and after 2, 4, 6, and 12 months of functional loading. Bone levels were calculated by digitally measuring the distance from the implant shoulder to the first bone-to-implant on periapical radiographs taken at surgery and after 2, 4, 6, and 12 months of functioning. RESULTS: Cumulative implant survival was 100% (n = 25/25). At implant placement and the 2-, 4-, 6- and 12-month monitoring appointments, mean ISQ values were 72.14 ± 5.61 (range = 50-81), 64.39 ± 8.12 (range = 44-74), 74.26 ± 7.14 (range = 44-74), 76.84 ± 7.65 (range = 60-83), and 78.13 ± 4.14 (range = 64-84), respectively, and mean crestal marginal bone loss was 0.19 ± 0.25, 0.22 ± 0.4, 0.3 ± 0.46, and 0.57 ± 0.62 mm, respectively. CONCLUSIONS: PTTM-enhanced dental implants were clinically effective in the prosthetic rehabilitation of postoncological patients. Larger long-term follow-up studies will help to evaluate clinical efficacy of PTTM dental implants.

Peri-implant diseases and systemic inflammation: A preliminary analysis from a cross-sectional survey of patients with hypertension.

BACKGROUND: The aim of this study was to investigate the association between peri-implant diseases and systemic inflammation assessed by serum C-reactive protein (CRP) levels in a sample of patients with hypertension. METHODS: A total of 151 participants with hypertension were included in a cross-sectional study. The population was divided into six groups according to their peri-implant and periodontal status (healthy controls, mucositis, peri-implantitis, periodontitis, periodontitis and mucositis, periodontitis, and peri-implantitis). Linear, logistic regression, and correlation analyses were performed. RESULTS: CRP levels were statistically significantly higher in participants with periodontitis alone (median 3.2 mg/L, interquartile range [IQR] 1.8, p = 0.012), combined with mucositis (3.10 mg/L, IQR 2.35, p < 0.001) or peri-implantitis (2.7 mg/L, IQR 2.53, p = 0.002) when compared to the healthy controls (1 mg/L, IQR 1.2). This association was independent of age, sex, smoking status, and adiposity differences. Participants with periodontitis with and without peri-implant diseases had the greatest odds of exhibiting CRP > 3 mg/L (odds ratio = 7.3, 95% confidence interval 1.6-33.9). CONCLUSIONS: Peri-implant diseases are associated with systemic inflammation, but the nature of the association should be further investigated.

Immediate vs. Delayed Placement of Immediately Provisionalized Self-Tapping Implants: A Non-Randomized Controlled Clinical Trial with 1 Year of Follow-Up.

This study aimed to examine the clinical and esthetic outcomes of immediately provisionalized self-tapping implants placed in extraction sockets or healed edentulous ridges one year after treatment. Sixty patients in need of a single implant-supported restoration were treated with self-tapping implants (Straumann BLX) and immediate provisionalization. The implant stability quotient (ISQ) and insertion torque were recorded intraoperatively. After one year in function, the implant and prosthesis survival rate, pink esthetic score (PES), white esthetic score (WES), and marginal bone levels (MBL) were assessed. Sixty patients received 60 self-tapping implants. A total of 37 implants were placed in extraction sockets and 23 in edentulous ridges, and then all implants were immediately provisionalized. All implants achieved a high implant stability with a mean insertion torque and ISQ value of 58.1 ± 14.1 Ncm and 73.6 ± 8.1 Ncm, respectively. No significant differences were found between healed vs. post-extractive sockets (p = 0.716 and p = 0.875), or between flap vs. flapless approaches (p = 0.862 and p = 0.228) with regards to the insertion torque and ISQ value. Nonetheless, higher insertion torque values and ISQs were recorded for mandibular implants (maxilla vs. mandible, insertion torque: 55.30 + 11.25 Ncm vs. 62.41 + 17.01 Ncm, p = 0.057; ISQ: 72.05 + 8.27 vs. 76.08 + 7.37, p = 0.058). One implant did not osseointegrate, resulting in an implant survival rate of 98.3%. All implants achieved PES and WES scores higher than 12 at the 1-year follow-up. The clinical use of newly designed self-tapping implants with immediate temporization was safe and predictable. The implants achieved a good primary stability, high implant survival rate, and favorable radiographic and esthetic outcomes, regardless of the immediate or delayed placement protocols.

Reliability assessment of the 2018 classification case definitions of peri-implant health, peri-implant mucositis, and peri-implantitis.

BACKGROUND: The purpose of this study was to evaluate the reliability and accuracy in the assignment of the case definitions of peri-implant health and diseases according to the 2018 Classification of Periodontal and Peri-implant Diseases and Conditions. METHODS: Ten undergraduate students, 10 general dentists, and 10 experts in implant dentistry participated in this study. All examiners were provided with clinical and radiographic documentation of 25 dental implants. Eleven out the 25 cases were also accompanied by baseline readings. Examiners were asked to define all cases using the 2018 classification case definitions. Reliability among examiners was evaluated using the Fleiss kappa statistic. Accuracy was estimated using percentage of complete agreement and quadratic weighted kappa for pairwise comparisons between each rater and a gold standard diagnosis. RESULTS: The Fleiss kappa was 0.50 (95% CI: 0.48 to 0.51) and the mean quadratic weighted kappa value was 0.544. Complete agreement with the gold standard diagnosis was achieved in 59.8% of the cases. Expertise in implantology affected accuracy positively (p < 0.001) while the absence of baseline readings affected it negatively (p < 0.001). CONCLUSION: Both reliability and accuracy in assigning case definitions to dental implants according to the 2018 classification were mostly moderate. Some difficulties arose in the presence of specific challenging scenarios.

Association between subclinical atherosclerosis and oral inflammation: A cross-sectional study.

BACKGROUND: The aim of this cross-sectional study was to investigate the association between carotid intima-media thickness (c-IMT) values and periodontal and peri-implant diseases in a sample of patients with hypertension. METHODS: A total of 151 participants with presence of at least one dental implant in function for >5 years were recruited. Anthropometric measurements, 24-h ambulatory blood pressure monitoring, ultrasound assessment of carotid arteries (c-IMT and presence of plaque) were recorded and venous blood samples obtained. An oral examination was performed by calibrated examiners to ascertain prevalence and severity of periodontal and peri-implant diseases. Binomial logistic regression was performed to investigate the potential association between various measures of exposure of dental diseases and predictors of cardiovascular risk (c-IMT > 0.9 mm and presence of plaque or their combination). RESULTS: Diagnosis of periodontitis (OR 6.71, 95% CI: 2.68-16.76, P < 0.001), cumulative mucosal/gingival inflammation (Periodontal Screening and Recording score) (OR 1.25, 95% CI:1.12-1.41, P < 0.001), and mucositis (OR 3.34, 95% CI:1.13-9.85, P < 0.05) were associated with c-IMT > 0.9 mm and/or plaque presence independent of age, sex, smoking, 24 h systolic blood pressure and body mass index differences. No statistically significant results were noted for peri-implantitis. Linear regression models confirmed a positive association of cumulative mucosal/gingival inflammation (ß = 0.011, SE 0.002, P < 0.001), diagnosis of periodontitis (ß = 0.114, SE 0.020, P < 0.001), and peri-implant diseases (ß = 0.011, SE 0.002, P < 0.001) with increased c-IMT values. CONCLUSIONS: This study confirms a positive association between mucosal/gingival inflammation and subclinical atherosclerosis assessed by c-IMT values and the presence of carotid plaque in patients with hypertension, independent of traditional cardiovascular risk factors. Future studies are needed to further characterize this relationship.

The Effect of Diabetes and Hyperglycemia on Horizontal Guided Bone Regeneration: A Clinical Prospective Analysis.

Guided bone regeneration (GBR) is a reconstructive procedure for treating atrophic alveolar ridges. This study aims to assess the correlation between different glycemic control levels and clinical findings in patients undergoing horizontal GBR before implant placement. The study population consisted of all patients requiring horizontal GBR. Patients were divided into three groups based on HbA1c levels: non-diabetic normoglycemic patients (HbA1c < 5.7%), non-diabetic hyperglycaemic patients (HbA1c < 6.5%), and patients with controlled diabetes (HbA1c < 7%). The primary outcomes were the horizontal (mm) and vertical (mm) dimensional changes of the alveolar ridge 6 months after the procedure. The study sample consisted of 54 patients. Sixty-eight implants (95.8%) were classified as "successful," meaning the possibility of inserting a standard-sized implant following the GBR (diameter ≥ 4 mm). There was a statistically significant difference between the three groups in terms of horizontal gain at 6 months: in particular, there was a statistically significant difference between group 1 and group 2 (p = 0.026) and between group 1 and group 3 (p = 0.030). The present investigation showed that patients with HbA1c levels below 7% could undergo GBR and obtain a statistically significant horizontal bone gain.

The Effect of an Optimized Diet as an Adjunct to Non-Surgical Periodontal Therapy in Subjects with Periodontitis: A Prospective Study.

Diet and nutrition are generally categorized as modifiable lifestyle risk factors for the development of periodontal disease because diet may influence a person's inflammatory status. This study aimed to evaluate the efficacy of the application of a diet plan focused on reducing inflammation and oxidative stress in treating periodontitis. Subjects suffering from periodontitis were divided into two groups. Both groups underwent non-surgical periodontal therapy, and in the optimized diet (OD) group, this treatment was associated with a diet plan. The sample consisted of 60 subjects; 32 (53%) were treated in the non-optimized diet group (ND group) and 28 (47%) in the OD group. In both groups, the periodontal treatment significantly improved the recorded periodontal outcomes between T0 and T1 (FMPS, FMBS, CAL, PPD). Inter-group differences were not statistically significant (p < 0.05). The linear regression models showed that the optimized diet was associated with a higher reduction in PPD and FMBS after the treatment, while patients who had higher LDL levels (over 100 mg/mL) had a less favorable improvement of PPD. The application of an improved diet plan can increase the reduction in PPD and FMBS after non-surgical periodontal therapy when compared with periodontal treatment alone.

Computer-assisted implant placement and full-arch immediate loading with digitally prefabricated provisional prostheses without cast: a prospective pilot cohort study.

BACKGROUND: Immediate loading of implant-supported full-arch rehabilitations has become routine practice when treating edentulous patients. The combination of static computer-aided implant surgery (s-CAIS) and digital prosthetic workflow could eliminate several treatment steps and facilitate prostheses delivery. The aim of this study is to evaluate the 1-year results of digitally prefabricated polymethyl methacrylate (PMMA) provisional prostheses without a cast for full-arch computer-assisted immediate loading. MATERIALS AND METHODS: A digital pre-operative treatment planning was realized for all patients: dental implants and screw-retained abutments were selected in the planning software and two surgical templates were fabricated for each patient. The first template was mucosa or teeth-supported to drill the holes for fixating pins, while the second template was placed after raising a full-thickness flap and was supported by pins as well as soft or hard tissue distal support. Furthermore, based on the surgical planning, interim prostheses were digitally designed and milled of PMMA resin blocks with subsequent pink resin veneering. Osteotomies and implant placement were performed through the surgical guides and all implants were immediately loaded with prefabricated full-arch interim prostheses directly connected to titanium copings with a flowable resin. RESULTS: A total of 55 dental implants were placed in ten patients. In all cases, interim prostheses allowed the insertion of titanium copings without the need of access hole enlargement or adaptation. All the prostheses had 1 year of functional loading to simulate the long provisional phase. No screw loosening occurred at the first removal of the prostheses after implant osseointegration. No fracture occurred during the whole period. After 1 year, the mean marginal bone loss level was 0.37 ± 0.06 mm, while the implant survival rate was 98.18% (n=54/55), with just one implant failing but not affecting final prosthesis delivery to the patient. CONCLUSIONS: Within the limitations of the present study, the authors concluded that digitally prefabricated provisional prostheses for full-arch immediate loading with s-CAIS could be a valid alternative treatment modality. Milled PMMA restorations proved to be durable enough during the long provisional phase, without prosthetic complications.

Clinical and volumetric analysis of peri-implant soft tissue augmentation using an acellular dermal matrix: A prospective cohort study.

BACKGROUND: The role of keratinized mucosa in promoting peri-implant health is controversial, however recent evidence support the use of soft tissue augmentation procedures around dental implants. Soft tissue substitutes have been proposed to replace autogenous connective tissue grafts, therefore the aims of this study are to report clinical and volumetric three-dimensional changes in mucosal thickness (MT) 1 year after treatment with an acellular dermal matrix (ADM). METHODS: Soft tissue augmentation was performed at second-stage surgery in the premolar maxillary area with an ADM. MT was assessed prior to implant placement and 1, 6, and 12 months after treatment. Digital linear and volumetric measurements were recorded at baseline and after 1 and 12 months. Furthermore, clinical parameters (Probing Pocket Depths, Bleeding On Probing, Plaque Index) and marginal bone loss were also recorded. Esthetic outcomes of treatment were evaluated objectively using the Pink Esthetic Score and through patient reported outcomes. RESULTS: Twelve patients were enrolled in this prospective study. Post-hoc analysis of the assessments with Tukey's honestly significant difference adjustment revealed that the MT had increased significantly from baseline to 1 month (P < 0.001), 6 months (P < 0.001) and 12 months (P < 0.001), and remained stable between 6 months and 12 months (P > 0.05). Based on the volumetric evaluation, a shrinkage of 23.31% occurred from 1 month to 12 months (P > 0.05). CONCLUSIONS: A significant increase in MT was reported after 1 year, with a mean gain of 1.25 mm. Soft tissues were stable, with no statistically significant differences between 6 months and 1 year.

Correlation between endodontic pulpal/periapical disease and retrograde peri-implantitis: A case series.

Retrograde peri-implantitis is a symptomatic complication, characterised by radiographic detection of bone loss at the periapex of the implant. The aim of this study was to investigate the possible endodontic aetiology, evaluating the effectiveness of surgical treatment without endodontic therapy of adjacent teeth. In the 10-year interval, three patients reported symptoms of retrograde peri-implantitis after a mean period of 30.6 days from implant placement. Mean follow-up after surgical procedures was 8.66 years, with an implant survival of 100%. Retrograde peri-implantitis was probably caused by colonisation of the apical surface of the implant by bacteria persisting in the area after endodontic failure/apical periodontitis, reactivated by drilling in the site. In all cases, the adjacent teeth remained vital during the years, showing that a direct cause-and-effect relationship between pulpal/periapical disease of adjacent teeth and retrograde peri-implantitis was never present.

Microbiological Profiles of Dental Implants in Metabolic Syndrome Patients: A Case-Control Study.

There is a lack of knowledge on the possible influence of systemic conditions on peri-implantitis. The aim of this case-control study is to evaluate the difference in terms of oral pathogens' concentrations in the peri-implant sulcus of a group of patients affected by metabolic syndrome (Mets) compared to healthy subjects. For each patient, peri-implant sulcular biofilm samples were obtained by inserting two sterile endodontic paper points in the deepest aspect of the peri-implant sulcus for 30 s. The quantitative real-time polymerase chain reaction was performed to evaluate total bacterial counts of six pathogens. Patients were screened for peri-implant diseases and clinical and radiographic parameters were recorded. A total of 50 patients was enrolled in the study, 25 affected by Mets and 25 healthy. Significantly higher bacterial counts were discovered for Aggregatibacter actinomycetemcomitans (p = 0.0008), Prevotella intermedia (p = 0.0477) and Staphylococcus aureus (p = 0.034) in MetS patients compared to healthy subjects. Performing a sub-group analysis, considering peri-implant status and dividing patients by MetS diagnosis, no statistically significant (p < 0.05) differences were found. For the first time, a correlation between MetS presence and a greater prevalence of some bacterial species in the peri-implant sulcus was reported, irrespectively from peri-implant status (health vs. disease).

Local/Topical Antibiotics for Peri-Implantitis Treatment: A Systematic Review.

Most studies indicate that the mechanical removal of the bacterial biofilm from the implant surface is the central goal of peri-implantitis therapy. However, controversial results in the treatment of peri-implantitis have led to the consideration of additional strategies that include surgical approaches and chemical adjuvants. Local/topical antibiotics, such as minocycline, azithromycin, tetracycline, amoxicillin, doxycycline, and metronidazole, may improve the efficacy of the definitive treatment of the disease, but the lack of conclusive findings prevents their use in clinical practice. This systematic review aimed to evaluate the effect of local/topical antibiotics for peri-implantitis treatment. Randomised controlled studies (RCT) on patients with peri-implantitis and comparing the efficacy of local/topical antibiotics vs. placebo or mechanical debridement were included. A systematic search strategy was carried out using three registered databases (PubMed, Web of Science, and Scopus). RoB2 was used to assess risk of bias. Five RCTs were identified (n = 250 patients and 333 implants). Contrast results emerged among the included studies, and a high heterogeneity level was observed. Risk of bias revealed some concerns for three studies out of five, while one study was judged at high risk. Only one study analysed the limitations of its findings. Overall, local antibiotic use can be considered a valid approach in the treatment of peri-implantitis. Therefore, future long-term clinical trials with standardised protocols and antibiotics with similar biological activity profiles should be tested to achieve a valid and definitive conclusion.

The Treatment of Peri-Implant Diseases: A New Approach Using HYBENX® as a Decontaminant for Implant Surface and Oral Tissues.

BACKGROUND: Peri-implantitis is a pathological condition characterized by an inflammatory process involving soft and hard tissues surrounding dental implants. The management of peri-implant disease has several protocols, among which is the chemical method HYBENX®. The aim of this study is to demonstrate the efficacy of HYBENX® in the treatment of peri-implantitis and to compare HYBENX® with other chemical agents used in the surgical treatment of peri-implantitis. METHODS: The present study included a population of ten subjects with severe peri-implantitis. The procedure used in the study involves the application of HYBENX® after open-flap debridement. Each patient has been followed for 12 months after a single application of the decontaminant agent. Clinical and radiographical parameters were recorded at baseline, 3 months, and 12 months after treatment completion. RESULTS: At baseline, a mean pocket probing depth (PPD) of 7.3 ± 0.5 mm and a mean clinical attachment level (CAL) of 8.8 ± 0.8 mm was recorded. An average residual PPD of 4.2 ± 0.5 mm and a mean CAL of 5.2 ± 0.8 mm were observed after 1 year. Additionally, the average of bone gain was about 3.4 mm, with a mean marginal bone level (MBL) change from 5.8 mm (baseline) to 2.4 mm (12 months). In total, 90% of the treated implants reached the success rate after the 1-year follow-up. Only in one case out of ten treated implants was resolution of the disease not achieved. CONCLUSION: Clinical improvements highlight that the procedure of open-flap debridement (OFD) + HYBENX® may be considered an effective technique in the treatment of peri-implantitis. From the results obtained, it can be concluded that the use of HYBENX® in the surgical treatment of peri-implantitis is promising. Overall, this protocol demands further studies to better understand the role and potential benefits of HYBENX® in the treatment of peri-implantitis.

Xerostomia and Clinical Outcomes in Definitive Intensity Modulated Radiotherapy (IMRT) Versus Three-dimensional Conformal Radiotherapy (3D-CRT) for Head and Neck Squamous Cell Carcinoma: A Meta-analysis.

BACKGROUND/AIM: Intensity modulated radiotherapy (IMRT) has been compared with three-dimensional conformal radiotherapy (3D-CRT) in randomized clinical trials for head and neck squamous cell carcinoma (HNSCC). The aim of this meta-analysis was to evaluate the efficacy and toxicity of IMRT and 3D-CRT and identify differences in grade ≥2 xerostomia incidence and clinical outcomes. MATERIALS AND METHODS: The preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement was applied. Random-effects models were used. Primary endpoint was xerostomia of grade 2 or worse. Secondary endpoints were overall survival (OS) and loco-regional control (LRC). RESULTS: Three randomized clinical trials representing 213 patients were identified. Global, grade ≥2 acute xerostomia and late xerostomia at 1 and 2 years after treatment were reduced with the IMRT technique (RR=0.71, 95%CI=0.59-0.86, RR=0.45, 95%CI=0.31-0.65 and RR=0.26, 95%CI=0.15-0.46, respectively). IMRT was not associated with significant OS and LRC improvement compared with 3D-CRT, with OR of 0.70 (95%CI=0.39-1.24; p=0.22) and 1.50 (95%CI=0.75-2.98; p=0.25). CONCLUSION: This meta-analysis explored the value of IMRT compared to 3D-CRT and confirmed the superiority of IMRT over 3D-CRT in terms of grade ≥2 xerostomia rates, but not on clinical outcomes. Its positive impact on tumor control and survival remains to be proven.

Attitude in Radiographic Post-Operative Assessment of Dental Implants among Italian Dentists: A Cross-Sectional Survey.

There is a lack of evidence in the attitude and prescribing practice of implantologists in dental implant post-operative assessment; therefore, the aims of this cross-sectional study were to investigate these habits and the knowledge about radiographic aspect of retrograde peri-implantitis (RPI) among Italian implantologists. A questionnaire was sent via email to dentists randomly selected from the register of implantology and oral surgery societies. It included three questions: the preferred X-ray after implant placement, the timing of post-operative assessment and the knowledge of the RPI radiographic representation. A final sample of 434 implantologists was included in the study. The majority of them (84.3%) perform a periapical X-ray as control radiograph and picked the correct radiographic representation of RPI (74.3%), without statistically significant differences (p > 0.05) for sex, age, years of working practice and number of implants placed per year. Just 47.7% of dentists perform a control radiograph at prostheses delivery, to establish a proper baseline. A statistically significant difference (p < 0.05) was detectable only for the number of implants placed per year, with dentists placing > 80 implants selecting the correct choice. To the best of authors' knowledge, this is the first study to report data on attitude of implantologists in radiographic imaging after implant placement.

Knowledge and Attitude towards Retrograde Peri-Implantitis among Italian Implantologists: A Cross-Sectional Survey.

BACKGROUND: Retrograde peri-implantitis (RPI) is a pathological entity with an unclear etiology (e.g., overheating during implant insertion, residual infection of the tooth replaced by the implant or the endodontic lesion of neighboring teeth) and an extremely low prevalence and has been scarcely investigated. Therefore, the aim of this cross-sectional survey was to evaluate the knowledge and attitude of Italian implantologists regarding RPI. METHODS: An anonymous questionnaire was sent via email to implantologists randomly selected, including a section about demographic information and questions related to RPI origin, radiographic representation, symptoms and treatment options. All questions were multiple answer and close-ended. Binomial logistic regression was performed to investigate the relationship between correct answers and the following independent variables: age, years of experience and number of dental implants placed per year. RESULTS: In total, 475 implantologists completed the questionnaire, with a response rate of 46.3%. Based on the results of the study, incorrect answers were associated with less experienced participants (<80 implants/year) for all questions evaluated, with the exception of treatment strategies. Furthermore, 26.7% of the survey takers did not recognize radiographic representation of RPI and 35.5% picked "implant removal" when asked about treatment modality. CONCLUSIONS: The majority of participants were able to recognize symptoms and indicated the probable causes of RPI; however, around 30% of them showed very limited knowledge of available management strategies.

The Use of a Non-Absorbable Membrane as an Occlusive Barrier for Alveolar Ridge Preservation: A One Year Follow-Up Prospective Cohort Study.

：The aims of this study were to obtain preliminary data and test the clinical efficacy of a novel nonporous dense-polytetrafluoroethylene (d-PTFE) membrane (permamem®, botiss) in alveolar ridge preservation (ARP) procedures with a flapless approach. A traumatic extraction was performed in the premolar maxillary area, and a d-PTFE membrane was used to seal the alveolar cavity: no biomaterial was used to graft the socket and the membrane was left intentionally exposed and stabilized with sutures. The membrane was removed after four weeks and dental implants were placed four months after the procedure. The primary outcome variables were defined as the dimensional changes in the ridge width and height after four months. A total of 15 patients were enrolled in this study. The mean width of the alveolar cavity was 8.9 ± 1.1 mm immediately after tooth extraction, while four months later a mean reduction of 1.75 mm was experienced. A mean vertical reduction of 0.9 ± 0.42 mm on the buccal aspect and 0.6 ± 0.23 mm on the palatal aspect were recorded at implant placement. Within the limitations of this study, the d-PTFE membrane proved to be effective in alveolar ridge preservation, with the outcomes of the regeneration not affected by the complete exposure of this biomaterial.

Salivary Levels of Titanium, Nickel, Vanadium, and Arsenic in Patients Treated with Dental Implants: A Case-Control Study.

BACKGROUND: Recent articles have hypothesized a possible correlation between dental implants dissolution products and peri-implantitis. The null hypothesis tested in this case-control study was that there would be no differences in salivary concentrations of titanium (Ti), vanadium (V), nickel (Ni) and arsenic (As) ions among patients with dental implants, healthy (Group A) or affected by peri-implantitis (Group B), compared to subjects without implants and/or metallic prosthetic restorations (Group C). METHODS: Inductively coupled plasma mass spectrometry was used to analyze saliva samples. One-way repeated-measure analysis of variance (ANOVA) was used to identify statistically significant differences in the salivary level of Ti, V, Ni and As between the three groups. RESULTS: A total of 100 patients were enrolled in the study (42 males and 58 females), distributed in three groups: 50 patients in Group C, 26 patients in Group B and 24 patients Group B. In our study, concentrations of metallic ions were higher in Group A and B, compared to the control group, with the exception of vanadium. However, there were no statistically significant differences (p > 0.05) for metallic ions concentrations between Group A and Group B. CONCLUSIONS: Based on our results, there are no differences in titanium or other metals concentrations in saliva of patients with healthy or diseased implants.