Dense Polytetrafluoroethylene Membrane versus Titanium Mesh in Vertical Ridge Augmentation: Clinical and Histological Results of a Split-mouth Prospective Study.

AIM AND OBJECTIVE: The aim of the present split-mouth prospective study was to evaluate clinically and histologically the bone regeneration obtained following preprosthetic vertical bone augmentation performed with titanium-reinforced dense polytetrafluoroethylene membrane (d-PM) compared to titanium mesh (TM). MATERIALS AND METHODS: Healthy adult patients presenting with bilateral partial edentulism in the posterior mandible requiring vertical ridge augmentation for implant placement purposes were consecutively included. One side of the mandible was randomly assigned to the use of d-PM, the other to TM. The graft consisted in a mixture of autogenous bone harvested nearby the surgical site and deproteinized bovine bone mineral particles in a 1:1 ratio. On each side during bone augmentation surgery, a 2-mm diameter mini-implant was inserted for clinical and histological analyses. After a healing period of 8 months, the second surgical phase was carried out to remove the nonresorbable barriers, to evaluate clinically the vertical bone gain, and to collect a bone biopsy that included the mini-implant. During the same surgical session, dental implants were inserted in a prosthetically guided position. RESULTS: A total of five patients were enrolled. Eight out of 10 sites healed uneventfully. In the remaining two sites, premature exposure of the TM was observed. Mean vertical bone gain of 4.2 and 1.5 mm was achieved in d-PM and TM groups, respectively (p = 0.06). A mean mineralized tissue of 48.28 and 35.54% was observed in d-PM and TM groups, respectively (p = 0.51). CONCLUSION: The vertical bone gain, although not significantly, was higher in the d-PM group. Similar histological outcomes were noticed if exposure did not occur. In case of wound dehiscence, major resorption was observed. CLINICAL SIGNIFICANCE: Both d-PM and TM can be used to augment atrophic localized ridges vertically. The outcome of bone regeneration seems to be impaired by exposure of the device. How to cite this article: Maiorana C, Fontana F, Rasia dal Polo M, et al. Dense Polytetrafluoroethylene Membrane versus Titanium Mesh in Vertical Ridge Augmentation: Clinical and Histological Results of a Split-mouth Prospective Study. J Contemp Dent Pract 2021;22(5):465-472.

[Epidemiological study on the population resident in the neighbourhood of an incinerator in Tuscany Region (Central Italy)]. / Indagine epidemiologica sulla popolazione residente nell'area circostante un impianto di combustione di rifiuti solidi in Toscana.

OBJECTIVES: to evaluate the health impact of the emissions of two waste incinerators located in the same area in Pietrasanta (Tuscany Region, Central Italy) at the border with the municipality of Camaiore, especially for diseases suggested in previous studies to be related to those emissions. DESIGN: epidemiological geographic study. SETTING AND PARTICIPANTS: the study population was defined on the basis of residence in the two municipalities and in the areas characterized by Particulate Matter with diameter equal or less than 2.5 µm (PM2.5) and poli-chloro-dibenzo-dioxin / poli-chloro-dibenzo-furans (PCDD/F) pollution defined with a dispersion model. From the resident population, for each cancer case it was sampled a control, matched to case by gender and age at case's diagnosis, and for each premature and low-weight newborn a control matched was sampled by year of birth, gender, and mother's residence. MAIN OUTCOME MEASURES: standardized (standard: European population) mortality and hospitalization rates in the residents of the two municipalities were calculated for liver, larynx, lung cancer, soft tissue sarcoma (STM), non-Hodgkin lymphoma (NHL), multiple myeloma, leukaemia, flu-excluded respiratory diseases, and circulatory diseases. The risk related to each PM2.5 and PCDD/F pollution level from the old incinerator for cancer and from the new plant for reproductive outcomes was analysed using logistic conditional regression model adjusted by gender and age. RESULTS: the mortality and hospitalization rates observed in the study area are similar to those calculated for the Versilia area excluded the two municipalities under study. There is a higher case distribution in the higher pollution levels, with significant increases in the highest level: • liver cancer: PM2.5 OR 2.3 (95%CI 1.5-3.6); PCDD/F OR 4.4 (95%CI 2.8-7.0); • larynx cancer: PCDD/F OR 3.2 (95%CI 1.5-6.7); • lung cancer: PCDD/F OR 1.5 (95%CI 1.1-2.0); • NHL: PCDD/F OR 8.5 (95%CI 3.1-23.5); • leukaemia: PCDD/F OR 4.1 (95%CI 1.8-9.3). The risks estimated for STM, although non significant, are consistent with those obtained in previous studies undertaken in areas characterized by dioxin pollution. There is a deficit of premature births in the area under study compared to the regional area, and no differences are observed among the different pollution areas. CONCLUSIONS: it cannot be excluded that the emissions from the old incinerator had a health impact on the population living in the neighbourhood. Nevertheless, it is possible that other risk factors (occupations and life styles) could have had a role on the obtained results. Better estimates could be obtained also taking into consideration the residential histories of the subjects under study.

Long-Term Retrospective Evaluation of Dental Implants Placed in Resorbed Jaws Reconstructed With Appositional Fresh-Frozen Bone Allografts.

INTRODUCTION: The aim of this study was to evaluate the outcome of fresh-frozen bone allografts in preprosthetic surgery for implant placement purposes. MATERIALS AND METHODS: The cohort comprised 45 patients treated with fresh-frozen bone block grafts and dental implants. Clinical and radiological evaluations were performed to evaluate the survival rate. The data were statistically analyzed with the Kaplan-Meier estimator to assess the influence of possible predictors of implant failure on survival. RESULTS: Overall, 262 implants were retrospectively analyzed. The survival rate was 90.84% over a mean follow-up of 50 months. Comparing the donor site and the position of the implants, no statistically significant differences could be detected (P = 0.7194 and P = 0.2901, respectively), whereas sex resulted in a marginally statistically significant difference (P = 0.0581). When considering age categorized on the median value (≤55/>55 years), age resulted in a statistically significant difference (P = 0.0340), with higher failures found in older people. CONCLUSION: Implant loss was strictly related to the lack of primary osseointegration. Female sex and old age were found to be risk factors, which could negatively influence implant survival.

Peri-implant conditions around sintered porous-surfaced (SPS) implants. A 36-month prospective cohort study.

OBJECTIVES: The specific aim of this study was to assess sintered porous-surfaced (SPS) implant system from a biological point of view, through a prospective study of the health status and the evolution of the peri-implant tissues over time and analysis of the changes observed in the various peri-implant parameters. MATERIAL AND METHODS: Hundred and fifty-one patients were treated consecutively from 2005 to 2007 using 280 SPS implants, which were restored with a single crown or a partial fixed denture. To accurately monitor the health and biological evolution of peri-implant soft and hard tissues, a number of clinical parameters were adopted, such as the modified Plaque Index (mPI), the modified sulcus Bleeding Index (mBI), Peri-implant Probing Depth (PPD), and Crestal Bone Level (CBL). Clinical and radiographic examinations were scheduled over a 36-month follow-up of functional loading according to a well-established protocol generally applied to determine implant success rates and Peri-implant Bone Loss (PBL). Statistical analysis was used to determine any significant differences or correlations (P = 0.05). RESULTS: A total of 259 SPS implants in 136 patients were followed up for 36 months. According to Buser's success criteria, the overall implant-based success rate was 98.1% and the mean PBL was 0.48 ± 0.29 mm. MBI and mPI mean values showed statistically significant differences between baseline and follow-up analyses (P < 0.001). No statistically significant differences in mean PPD values were found between baseline and control analyses (P = 0.060). CONCLUSION: This prospective cohort study revealed that the biological behavior of SPS implant system was characterized by high tissue stability during the observation period, both as regards soft and hard tissues. In particular, the crestal bone remodeling pattern was very similar to that reported in other studies, confirming that the bone loss around SPS implants, at least at 36 months, seems to be predictable.

Efficacy of the Sausage Technique in Rebuilding the Crestal Buccal Bone Thickness: A Retrospective Analysis.

The goal was to evaluate the efficacy of the sausage technique in reconstructing the crestal buccal bone thickness, focusing on the distribution shape of the regenerated volume. Ten implants were placed in five patients with Cawood-Howell class IV defects. A cone beam computed tomography (CBCT) was executed at T0 (before surgery). Guided bone regeneration (GBR) with the sausage technique utilized a resorbable collagen membrane, made of a 50% autologous bone and a 50% anorganic bovine bone matrix (ABBM) mixture. After 6 months, a CBCT (T1) was performed before implant placement. Using CBCT software, a plane parallel to the implant axis intersected perpendicular planes every 1.5 mm from the crest level. T0 and T1 CBCT sections were analyzed, yielding 140 measurements. Statistical analysis via SPSS revealed a significant increase in thickness (average 2.82 ± 1.79 mm). Maximum gains occurred at 4.5 mm from the coronal crest line (3.8 ± 1.51 mm). The GBR sausage technique was effective with minimal post-operative complications, yielding the biggest gain at the mid-ridge sagittal area. Within the analysis limitations, it can be assumed that the sausage technique is effective for horizontal GBR in the maxilla, but a lesser volume might be achieved at the crestal level because it seems to follow a bowed regeneration shape.

Rough Implants in Vertically Augmented Bone: A Retrospective Study with 4 to 15 Years of Follow-up

Although vertical guided bone regeneration (v-GBR) is a popular technique for treating alveolar bone deficiency, there are no long-term studies analyzing the longevity and success of the results. This retrospective study analyzes the clinical and radiographic outcomes of oxidized implants placed after v-GBR, with a follow-up period of 4 to 15 years. The study considers 41 v-GBR patients receiving one or more dental implants between 2001 and 2013 (115 implants total). Clinical and radiographic outcomes were recorded during follow-up visits. A multiple logistic regression model was used to analyze the correlation between peri-implantitis and demographic, surgical, and clinical variables, as well as the length of the follow-up period. The cumulative survival rate of the implants over the mean follow-up period of 9.6 ± 3.4 years was 95.7%, with peri-implantitis observed in 26.1% of the implants. The variables that correlated with the occurrence of peri-implantitis were smoking (OR = 8.5, 95% CI = 1.6 to 44.5, P < .01), posterior mandible implant position (OR = 2.1, 95% CI = 1.2 to 3.9, P < .01), and the length of the follow-up period (OR = 1.5, 95% CI = 1.1 to 2.2, P < .01). In this study, smoking, time since the surgery, and the implant position were associated with peri-implantitis developing on rough surface implants. Along with with previous long-term follow-up studies, this suggests that oxidized surface implants have a higher risk of peri-implantitis than machined ones.

Efficacy of rituximab in severe and mild abdominal vasculitis in the course of mixed cryoglobulinemia.

Abdominal vasculitis represents a rare, but life-threatening manifestation in mixed cryoglobulinemic syndrome (MCsn), despite aggressive immunosuppressive treatments. Anti-CD20 monoclonal antibody, rituximab (RTX) has already been used with good results in MC in preliminary studies. No data have been provided, however, on the efficacy of RTX in gastrointestinal involvement of MCsn. Herein, we report the favourable outcomes of the gastrointestinal manifestations in five patients treated with RTX, where the diagnosis of abdominal vasculitis was confirmed by histopathological findings in 2 out of 5 patients, while in the other three patients the diagnosis was made on the basis of positive endoscopy or by integrating clinical and laboratory data.

A Clinical and Radiographic Retrospective Study on 223 Anodized Surface Implants with a 5- to 17-Year Follow-up.

The aim of this study is to evaluate the long-term performance of anodized surface implants placed in native bone and followed-up for up to 17 years. Success and survival rates, prevalence of peri-implantitis, and the correlation between the presence of peri-implantitis and other clinical and demographic variables were calculated. After a mean follow-up time of 10.4 years (range: 5 to 17 years), 91.7% of 223 analyzed implants were still in function. Peri-implantitis affected 63 implants (28.3%) in 26 patients (44%). Eleven implants with peri-implantitis (4.9%) failed. Within the limits of this retrospective analysis, anodized implants appear to be prone to peri-implantitis, mainly in the posterior mandible and in patients with unsatisfactory plaque control.

Bacterial Biofilm Morphology on a Failing Implant with an Oxidized Surface: A Scanning Electron Microscope Study.

This case report provided a unique opportunity to investigate the extent of microbiota infiltration on the oxidized implant surface that has been compromised by peri-implantitis. Scanning electron microscopic analysis confirmed the etiologic role of the bacteria on the loss of supporting structure and the difficulty in complete removal of bacterial infiltration on the implant surface. This case report emphasizes the need to perform definitive surface decontamination on failing dental implants prior to a regeneration procedure.

A Four-Year Survival Rate Multicenter Prospective Clinical Study on 377 Implants: Correlations Between Implant Insertion Torque, Diameter, and Bone Quality.

The purpose of this study was to evaluate the survival rate and incidence of prosthetic complications in 377 implants with a double octagon connection. Furthermore, the correlations among implant dimensions (diameter and length), bone quality, and insertion torque were investigated. A 4-year multicenter prospective clinical study was designed to evaluate the survival rate of 377 dental implants inserted in 189 patients between January 2004 and April 2010. After an average follow-up of 46 months, the implant survival rate was 99.7%, and the incidence of complication was 0.53%. Moreover, insertion torque was statistically related in a significant way to implant diameter. The connection system seemed to reduce the risk that the prosthetic component screw would loosen. Within the limits of this study, it was observed that a wider diameter corresponded to a higher implant primary stability. Implant length did not seem to be critical in obtaining higher primary stability.

Effects of different abutment material and surgical insertion torque on the marginal adaptation of an internal conical interface: an in vitro study.

PURPOSE: To evaluate the marginal adaptation at implant-abutment connection of an implant featuring a conical (45° taper) internal hexagonal abutment with a connection depth of 2.5mm, comparing the performance of two identical abutments of different material (titanium grade-4 and Co-Cr-alloy). METHODS: Twenty implants (3.75 mm×15 mm) were connected to non-matching abutments (5.5 mm×10 mm) of two different materials (titanium grade-4: n=10; Co-Cr-alloy: n=10). The specimens were separately embedded in epoxylite resin, inside copper cylinders, and submerged without covering the most coronal portion (5 mm) of the fixture. Five specimens per group were stressed simulating a surgical 100 Ncm insertion torque, while the others had no torque simulation. All specimens were subjected to a non-axial static load (100 N) in a universal testing machine, under an angle of 30° with respect to the implant axis. Once 100 N load was reached, low shrinkage self-curing resin was injected inside the cylinders, and load was maintained until complete resin polymerization. Specimens were cut and analyzed with optical and scanning-electron-microscope (SEM) to evaluate the marginal adaptation at the implant-abutment connection. Statistical analysis was performed using one-way ANOVA (p=0.02). RESULTS: None of the 20 samples failed. The implant-abutment connection was able to guarantee a good optical seal; SEM analysis confirmed the absence of microgaps. CONCLUSIONS: Within the limits of this study (small sample size, limited time) the marginal adaptation of the implant-abutment connection was not affected by the abutment material nor by the application of surgical insertion torque.

Esthetic integration between ceramic veneers and composite restorations: a case report.

The tooth structure preservation is the best way to postpone more invasive therapies. Especially in young patients more conservative techniques should be applied. Bonded porcelain veneers and even more the direct composite restorations, are the two therapeutic procedures that require the fewer sacrifice of dental tissue, finalized to the optimal recovery of aesthetic and functional outcome.Although the two techniques require different methods and materials, is possible to achieve a correct integration of both the methods by some technical and procedural measures. In the presented case is planned a rehabilitation of the four upper incisors by ceramic veneers and direct composite restorations.Care is taken for the surface treatment of ceramic restorations, with the objective of achieving integration, not only between natural teeth and restorations, but also between the different materials in use.The purpose of this article is to show how a proper design of the treatment plan leads to obtain predictable results with both direct and indirect techniques.