Implant Dentistry

Device Legislation...... Now Tread Cautiously No abstract available

The Sinus Bone Graft— Third Edition 2019 No abstract available

Ridge Architecture Preservation Following Minimally Traumatic Exodontia Techniques and Guided Tissue Regeneration Objective: To compare hard-tissue healing after 3 exodontia approaches. Materials and Methods: Premolars of dogs were extracted: (1) flapless, (2) flap, and (3) flap + socket coverage with polytetrafluoroethylene (dPTFE) nonresorbable membrane (flap + dPTFE). Animals were euthanized at 1 and 4 weeks. Amount of bone formation within socket and socket total area were measured. Results: Amount of bone formation revealed significant difference between 1 and 4 weeks; however, there was no differences among groups. Socket total area decreased after 4 weeks, and the flap + dPTFE group showed significantly higher socket total area. As a function of time and group, flap + dPTFE 4 weeks presented similar socket total area values relative to flap + dPTFE at 1 week, and significantly higher socket total area than flapless and flap. The histological sections revealed almost no bone formation within socket after 1 week, which increased for all groups at 4 weeks. Conclusion: Socket coverage with polytetrafluoroethylene (dPTFE) membrane showed to effectively preserve bone architecture. Bone formation within sockets was not influenced by tooth extraction technique.

Cone-Beam Computed Tomography Evaluation of the Submandibular Fossa in a Group of Dental Implant Patients Objective: In the mandibular posterior region, presurgical imaging can provide valuable information of anatomical variants. The aim of this study is to evaluate submandibular fossa anatomy in the posterior mandible using cone-beam computed tomography (CBCT) scans. Study Design: One hundred thirty-two preimplant CBCT examinations were used. Several morphometric measurements were performed in the submandibular fossa. Moreover, each patient was classified according to the Kennedy classification. Statistical analysis was used to test the relationship among measurements, sex, side, and each tooth. Results: A total of 2412 measurements were performed from all patients. The deepest concavity at the submandibular fossa in all Kennedy Class groups was in the 1st and 2nd molars. The concavity depth was statistically higher in class I group for 1st and 2nd molars than the other Kennedy Class groups. Class IV group showed less depth than the other groups. When compared with female patients, all measurements in male patients were statistically higher. The patients older than 35 years showed higher measurements than the patients younger than 35 years. Conclusions: Mandibles with any lingual concavity pose a potential increased risk of lingual cortical perforation during surgery. This study revealed that the alveolar bone resorption occurs both vertically and horizontally, and the preservation of teeth can limit the bone resorption.

Distribution of Trabecular Bone Density in the Maxilla and Mandible Introduction: Implant osseointegration is strongly influenced by the bone quality at the implant insertion site. The present work aims to create distribution diagrams showing the average bone density at each position within the jaws. Materials and Methods: Data were retrospectively collected from 4 oral surgeons who sought bone-density measurements during implant placement using a torque-measuring implant micromotor. Statistical analyses were performed to investigate whether bone density correlated with the patients' sex and age and whether the bone-density values at different positions within each arch correlated to each other. Results: Records of 2408 patients and 6060 bone-density readings were retrieved, and density distribution diagrams were created. Density values showed a significant variation within subjects. Within the same jaw, density between adjacent positions showed significant differences. Density at a given position correlated significantly with that at the other positions in most cases. Bone density was significantly lower in women than in men; no significant correlation was found between bone density and the patient age. Conclusions: Bone density of patients displays significant interindividual variation, thus meaningful assessment must be conducted on a patient-by-patient basis.

Alveolar Ridge Expansion by Osseodensification-Mediated Plastic Deformation and Compaction Autografting: A Multicenter Retrospective Study Introduction: Osseodensification preserves bone bulk, facilitates compaction autografting, and deforms trabecular bone in an outward strain, which result in alveolar ridge plastic expansion. The aim of this retrospective study was to evaluate ridge expansion after osseodensification. Materials and Methods: Patients treated with implant placement through osseodensification were evaluated. The alveolar ridge width was measured at the level of the crest and 10 mm apical to the crest before and after osseodensification. Insertion torque and implant stability quotient (ISQ) values were recorded at implant placements. Expansion values were grouped into the following 3 groups according to the initial alveolar ridge width: group 1: 3 to 4 mm (n = 9), group 2: 5 to 6 mm (n = 12), and group 3: 7 to 8 mm (n = 7). Results: Twenty-one patients who received 28 implants were included. Twenty-six implants were integrated, resulting in a survival rate of 92.8%. There was a significant difference in the mean expansion value at the coronal aspect of the ridge between group 1, group 2, and group 3 (2.83 ± 0.66 mm, 1.5 ± 0.97 mm, 1.14 ± 0.89 mm, P < 0.05). The mean torque and ISQ values were 61.2 ± 13.9 Ncm and 77 ± 3.74. Conclusion: Osseodensification can alter ridge dimensions and allow for ridge expansion. Greater expansion can be expected at the crest in narrow ridges with adequate trabecular bone volume.

Prevalence of Maxillary Sinus Pathology Based on Cone-Beam Computed Tomography Evaluation of Multiethnicity Dental School Population Objective: The goal of the study was to evaluate prevalence of maxillary sinus pathology among populations considered for possible sinus augmentation procedures for dental implants. Study Design: Eight hundred twenty-one cone-beam computed tomography (CBCT) scans were retrospectively evaluated for prevalence of maxillary sinus pathology. Scans were classified based on the type of sinus pathology detected. Categories of sinus findings were healthy, mucosal thickening larger than 3 mm, polypoidal mucosal thickening, partial opacification, complete opacification, and others. Age, sex, ethnicity, and dentition status were evaluated to determine associated relationships with the incidence of pathology. Results: Sixty-two percent (62.79%) of scans presented with bilateral healthy sinuses and 37.21% of scans exhibited pathology. 73.38% of sinuses were classified as clinical healthy, 14.93% presented with mucosal thickening, 8.53% with polypoidal mucosal thickening, 2.13% with partial opacification, 0.66% with complete opacification, and 0.37% with a foreign body. Sex is found to be a significant factor with higher pathology incidence rates in male patients. Age is a significant factor with higher pathology incidence rates in older subjects. Dentition status and ethnicity did not have a significant association with pathology incidence rates. Conclusions: The prevalence of maxillary sinus pathologies and associations with age, sex, ethnicity, and dentition status were obtained. Thirty-seven percent of scans would require further medical consultation before proceeding with maxillary sinus augmentation surgery for dental implants.

Feasibility of Assessing Maxillary and Mandibular Bone Mineral Density for Dental Implantation by Using Multidetector Computed Tomography Purpose: The purpose of this study was to evaluate the feasibility of measuring bone mineral density (BMD) of the maxillary and mandibular bones for dental implantation by using multidetector computed tomography (MDCT). Materials and Methods: We performed MDCT in 141 patients (78 women and 63 men) at the lumbar vertebrae and at the maxillary and mandibular bones, with a view to dental implantation, from July 2015 to June 2017. Quantitative CT (QCT) using MDCT was performed to obtain Hounsfield unit (HU) values for the maxillary and mandibular bones and to obtain T scores for the lumbar vertebrae. We statistically analyzed the relationships among HU values, and the correlations of QCT values with T scores and of T scores with HU values. Results: There were statistically significant correlations among all these parameters. Conclusions: QCT using MDCT of the maxillary and mandibular bones seems to be a feasible method for measuring BMD before dental implantation.

Effect of Steam Heat Sterilization on the Accuracy of 3D Printed Surgical Guides Introduction: Steam heat sterilization could be one of the factors that affects the dimensional accuracy of surgical guides, leading to an error during guided implant surgery. Objective: The purpose of this study was to investigate the effect of steam heat sterilization on the dimensional changes of surgical guides. Materials and Methods: A total of 27 surgical guides, which were made by either Formlabs printer (Formlabs Inc., Somerville, MA) or Simplant (DENTSPLY Implants NV, Hasselt, Belgium), were scanned using an intraoral scanner before and after sterilization. The dimensional changes at the center of the implant sleeves were analyzed using the computer-aided design interactive software for 65 implant sites before and after steam heat sterilization at 121°C for 20 minutes. Results: There was no significant difference between the mean x, y, and z axes of the center of the sleeves when measured before and after sterilization (P values were 0.37, 0.24, and 0.29, respectively). Nonparametric analysis showed no significant difference between the mean deviations of either surgical guide (P = 0.908). Conclusion: Steam heat sterilization has a nonsignificant effect on the dimensional changes of the tested surgical guides.

Fracture of Zirconia Abutments in Implant Treatments: A Systematic Review Purpose: The purpose of this systematic review was to identify and summarize clinical studies related to the fracture of zirconia abutments in implant treatments. Material and Methods: Medline, Embase, and Cochrane library searches were performed and complemented by manual searches from database inception to February 11, 2018, for title and abstract analysis. Results: Initially, 645 articles were obtained through database searches. Fifty-three articles were selected for full-text analysis, and 15 studies met the inclusion criteria. The selected studies were analyzed regarding fracture rate, abutment-implant connection, time point of fracture, location of critical crack, causes, managements, and preventive measures with respect to zirconia abutment fracture. Conclusions: Lower fracture rates were reported for internal connection with metal component (2-piece) zirconia abutments compared with external and internal full-zirconia connection (one-piece) zirconia abutments. Overpreparation and overload should be avoided in case of zirconia abutments.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com