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Aim The aim of this study was to analyze, by the aid of microbiological analysis and the field emission scanning electron microscopical (FE-SEM) analysis, the role of high-density polytetrafluoroethylene (d-PTFE) membranes in avoiding the microbial colonization of a nanocrystalline hydroxyapatite (nc-HA) bone graft and the involvement of this colonization in the healing process. Materials and methods Six patients underwent extraction of unrecoverable teeth, and a socket preservation technique was carried out with nc-HA synthetic bone graft and then covered with a d-PTFE membrane. After 28 days from surgery, FE-SEM analysis and BioTimer assay technique to assess the microbiological count of streptococci species were carried out. Data were collected and analyzed by the Student's t test (confidence interval: 95%). Results The mean amount of bacteria measured on the upper side of the membrane was 6.52 ± 0.50 CFU, while on the lower side, it was 6.59 ± 0.40 CFU. Significant differences were not found between the two sides of the membrane or between the different sectors (p > 0.05). The FE-SEM analysis revealed structured biofilms on both sides of the membrane: species of cocci, bacilli, and fusobacteria were recognizable in occasional settled vegetations. Conclusion Since the amount of bacteria found was low, the improved impermeability of the d-PTFE membrane permitted the healing process to proceed uneventful and without signs of infection or inflammation. Clinical relevance The infection of the graft site could lead to a failure of the socket preservation technique which could delay or compromise the rehabilitation following procedures. The use of d-PTFE can improve the bone regeneration thanks to its antimicrobial properties.

The aim of this study was to compare a transposed with a repositioned flap by assessing the periodontal effects on the second molar and primary healing after extraction of partially impacted lower third molars. A total of 24 patients requiring partially impacted mandibular wisdom tooth removal were enrolled in the study. The test group (n = 12) underwent a transposed flap procedure, whereas the control group (n = 12) underwent a repositioned flap procedure. Plaque index, probing depth, bleeding on probing, and width of keratinized tissue were recorded the day of surgery (T1) and after 60 days (T4). Wound dehiscence was assessed on the mesio-distal and bucco-lingual directions at days 2 (T2), 7 (T3), and T4. No significant differences have been observed in the periodontal parameters between the groups at T1 and T4 (P > 0.05). Similarly, no difference was found at T2, T3, and T4 in wound dehiscence incidence (P > 0.05). To date, no data exists on the use of transposed flaps in third molar surgery; thus a comparison of results cannot be done. Further studies with larger population are needed to investigate the potential advantages of this type of flap.

Objectives The aim of this study was to investigate the morphological and surface roughness changes in dental root samples following periodontal scaling by hand curette, piezoelectric ultrasonic devices or a combination of these. Methods Twenty-four monoradicular teeth extracted as a result of periodontal disease were divided into 4 groups: Group A was treated by piezoelectric ultrasonic scaler Piezon® Master 400; Group P by piezoelectric ultrasonic scaler PiezoSmart® ; Group C using Gracey curette 7/8; Group AC by a combined technique of piezoelectric ultrasonic scaler Piezon® Master 400 and Gracey curette 7/8. The treated samples were then analysed using a white light interferometer and scanning electron microscopy (SEM). Results Roughness analysis revealed major surface alterations in Group C (Sa = 24.98 μm); the samples treated using the combined technique (Group AC) showed reduced but still significant alteration (Sa = 14.48 μm), while samples treated with the piezoelectric ultrasonic devices (Group A and Group P) presented the lowest roughness values (Sa = 8.99 and Sa = 4.45 μm, respectively). A significant difference was found between groups C and P (P = 0.036). SEM analysis confirmed the roughness analysis revealing non-homogeneous surfaces in Group C, while a less morphological alteration was noted in the other groups. Conclusion All periodontal devices used in this in vitro study produced a certain degree of surface alteration. Hand curettes appear to have a major impact on surface integrity compared with piezoelectric ultrasonic devices.

Alveolar ridge preservation has become a very common procedure following tooth extraction. This study presents a clinical, histologic, and histomorphometric analysis of postextraction bone changes using nanocrystalline hydroxyapatite (nc-HA) and exposed high-density polytetrafluoroethylene (d-PTFE) membrane. A total of 10 extraction sockets were treated. Clinical measurements were taken after tooth extraction with a customized acrylic stent to ensure the same measurement points. At 6 months, clinical measurements were repeated and bone specimens taken. An overall bone reduction was observed. The histologic and histomorphometric analysis revealed newly formed bone (25.92% ± 18.78%), soft tissue (28.55% ± 9.73%), and residual graft particles (15.43% ± 11.08%). Further studies are necessary to evaluate the efficacy of this technique over the long term.

Purpose. Various parameters can influence temperature rise and detection during implant site preparation. The aim of this study is to investigate local temperature values in cortical and corticocancellous bovine bone during early stages of piezoelectric implant site preparation.Materials and Methods. 20 osteotomies were performed using a diamond tip (IM1s, Mectron Medical Technology, Carasco, Italy) on two different types of bovine bone samples, cortical and corticocancellous, respectively. A standardized protocol was designed to provide constant working conditions. Temperatures were measured in real time at a fixed position by a fiber optic thermometer.Results. Significantly higher drilling time (154.90 sec versus 99.00 sec;p<0.0001) and temperatures (39.26°C versus 34.73°C;p=0.043) were observed in the cortical group compared to the corticocancellous group. A remarkable variability of results characterized the corticocancellous blocks as compared to the blocks of pure cortical bone.Conclusion. Bone samples can influence heat generation duringin vitroimplant site preparation. When compared to cortical bone, corticocancellous samples present more variability in temperature values. Even controlling most experimental factors, the impact of bone samples still remains one of the main causes of temperature variability.