Resistance to Torsion of Cement vs Screw-Retained Abutments Under a Tangential Load: A Pilot Study.

The aim is to compare the resistance to torsion between 2 implant systems with internal hexagon connection: one using screw-retained abutments (Titanium Fix) and the other using cementable abutments (ITEC) under a tangential load. An in vitro experimental study was carried out. Fourteen implants, 7 implants from each system, were included in this study. The implants were placed at a 45° angle into metal blocks to simulate their position in the maxilla. Then, implants were subjected to a resistance test on a CMT5L universal testing machine, and the maximum load was applied to each sample. The maximum force with which the torsion was achieved in each sample was analyzed. The data were tested using the Shapiro-Wilk test and showed normal distribution. Student t test was used to examine statistical significance between the two groups, and the P value was set at P < .05. There was a statistically significant difference between the two groups (P = .001). ITEC implants with a cementable abutment showed greater flexural strength compared to the Titanium Fix with a screwed abutment implant system. The cemented abutment showed more resistance to torsion against a tangential load compared with the screwed abutment.

Clinical-Epidemiological Profile of Dental Professionals Associated with COVID-19 Infection in Southern Peru: A Cross-Sectional Study.

Dental professionals have been identified as being at high risk for COVID-19 infection due to close contact with patients and the nature of dental treatments. However, the prevalence of infected dentists in Peru has not been determined. An online electronic survey was sent to dentists registered with the College of Dentists of Arequipa to collect sociodemographic data, medical conditions, and employment characteristics during the COVID-19 pandemic. The clinical characteristics and adverse effects of dentists diagnosed with COVID-19 were also recorded. The overall prevalence of COVID-19 infection was 44%. The highest number of diagnosed patients ranged in age from 31 to 40 years (n = 111; 48.9%). A total of 45.9% of female and 41.6% of male dentists were diagnosed with COVID-19 (p = 0.425). A relationship was found between the district of origin and infection, and dentists working in the public sector during 2021 showed a greater trend of becoming infected (57.6%) (p < 0.05). The antigen swab test was the diagnostic test most frequently used (38%), and cough was the symptom most reported. Only 0.6% reported being hospitalized, 10.6% reported needing oxygen during hospitalization, and 0.6% were admitted to an intensive care unit. As in previous studies in other countries, the rate of COVID-19 infection among Peruvian dentists is high. It is recommended that dentists carry out infection control measures while ministries of health and dental associations take measures to ensure their safety.

Horizontal ridge augmentation with guided bone regeneration using particulate xenogenic bone substitutes with or without autogenous block grafts: A randomized controlled trial.

BACKGROUND: To evaluate dimensional bone alterations following horizontal ridge augmentation using guided bone regeneration (GBR) with or without autogenous block graft (ABG) for the rehabilitation of atrophic jaws with dental implants. MATERIALS AND METHODS: Forty-two patients, with 42 severe horizontal bone atrophy sites in the maxilla or mandible were randomly assigned to two groups: ABG or GBR. The ABG group received a combination of ABG with particulate xenograft, covered by a collagen membrane, while the GBR group received particulate xenograft alone, covered by a collagen membrane. After 6-9 months of healing, implants were inserted. All implants were definitively restored 6 months after implant placement. Radiographic examination (cone-beam computed tomograms) was performed immediately after bone grafting procedure (T0), at 6 months (T6), and at 18 months (T18), to evaluate the amount of horizontal bone width (HBW) gain. Patient demographic information, amount of ridge width augmentation, implant survival, complications, and contributing factors were gathered and analyzed. RESULTS: Thirty-nine patients completed the study. Both groups developed enough bone ridge width for implant placement. A total of 65 implants were placed. Implant survival rate was 100% in both groups at T18. Mean increases in HBW amounted to 5.6 ± 1.35 mm in GBR sites and 4.8 ± 0.79 mm in ABG sites at T18. There was no statistically significant difference in HBW gain obtained in the GBR group when compared to the ABG group at 6 months (P = 0.26) or 18 months (P = 0.26). However, the ABG group had a statistically significant higher prevalence of sensory disturbances (P = 0.02) and hematomas (P = 0.002) compared to the GBR group. CONCLUSION: These findings indicated that either GBR with or without ABG is an effective approach in augmenting resorbed horizontal deficient ridges prior to implant placement. However, more complications may be seen with the use of ABG related to the donor sites.

A Case Series of Vertical Ridge Augmentation Using a Nonresorbable Membrane: A Multicenter Study.

Vertical ridge augmentation (VRA) using titanium-reinforced dense polytetrafluorethylene (d-PTFE) membranes has been associated with promising clinical outcomes. This retrospective multicenter case series was prepared for the purpose of identifying the elements that contribute to the predictability of this surgical technique. VRA procedures were carried out in 35 patients (13 male and 22 female) with an age range of 43 to 76 years. The average bone gain was 5.44 mm. In the Kaplan-Meier estimates of cumulative survival calculated at 15 months, membrane exposure (P = .045) was a predictor for VRA.

Tissue Engineering Therapy for Atrophic Maxilla Using Minimally Manipulated CD90 and CD105 Bone Marrow Stem Cells: A Case Report.

Bone deficiencies in the jaws of edentulous patients limit the possibility of successful placement and osseointegration of endosseous implants. Bone resorption is defined as a vertical and horizontal loss of quality and quantity in the residual bone ridges; lack of bone structure requires bone grafting procedures to enable implant placement and to improve the function, predictability, and longevity of implants. The objective of this case study was to demonstrate the feasibility of a novel cell therapy treatment for localized jaw bone defects with tissue repair cells composed of a mixture of bone marrow-derived cells, including CD90+ mesenchymal stem cells and CD105+ monocytes/macrophages, and xenograft blocks, in what would be a safe and efficacious approach to the regeneration of localized craniofacial bone defects. The use of stem cells represents an alternative that could offer improved results, better quality histologically, and greater quantity in millimeters of tissue in bone regeneration.

Assessment of Marginal Peri-implant Bone-Level Short-Length Implants Compared with Standard Implants Supporting Single Crowns in a Controlled Clinical Trial: 12-Month Follow-up.

In oral rehabilitation, crown-to-root ratio is accepted as an indicator of bone loss, and this concept was transferred to implants. Recent studies have indicated that there is no significant difference between short and standard implants. The aim of this study was to compare marginal bone-level alteration through radiographic evaluation and clinical parameters between short and standard implants supporting single crowns. This prospective clinical trial study included 82 systemically healthy, nonsmoking subjects. Patients were divided into two groups: one group for short dental implants measuring 5.5 or 7 mm, and one group for standard dental implants measuring 10 or 12 mm, in accordance with the individual needs of the patient. A clinical dental history was taken for each subject, including model casts, dental radiography, and cone beam computed tomography. A periapical analysis was also performed using ImageJ computer software to establish the initial bone measurement and periapical bone loss. A statistically significant difference was found in favor of the standard-length implants after 12 months, with greater gingival recession around the implant; however, bone loss in the short implants did not exceed 0.53 mm. The treatment with 5.5- to 7-mm-length implants is as reliable as treatment with 10- or 12-mm implants. Peri-implant bone loss is minimal, and therefore use of short implants can be recommended as treatment for the restoration of partially edentulous patients without the need for splinted crowns.