1,720,984 research outputs found
Influence of piezosurgery on the intra- and post-operative course: Preliminary results
Full text linkOBJECTIVES. To compare the effects of piezoelectric and traditional surgical molar extraction in terms of soft-tissue healing and patient discomfort. MATERIALS AND METHODS. Six patients underwent extraction of the low third molar (impacted). In a seventh patient, the first inferior premolars were extracted for orthodontic purposes. A total of 9 procedures were performed: 6 were carried out with traditional methods, and 3 were done with piezoelectric surgery. Mucosal biopsies taken from the surgical site the day of the procedure (day 0) and 6 days and 4 weeks after the procedure were subjected to histological analysis. Patient discomfort was rated subjectively by means of a visual analogue scale (VAS). RESULTS. Histological analysis of mucosal specimens revealed no significantly differences between the two methods in terms of the inflammatory reaction provoked. VAS scores for the patients treated with traditional methods ranged from 5 mm to 27 mm; those treated with piezoelectric surgery had scores between 19 mm and 31 mm. CONCLUSIONS. The results obtained in this preliminary study do not reveal any substantial differences in the post-operative effects of piezosurgical and traditional surgical extraction methods. Analysis of a larger number of cases is needed to draw meaningful conclusions
Hard and Soft Tissue Evaluation of Different Socket Preservation Procedures Using Leukocyte and Platelet-Rich Fibrin: A Retrospective Clinical and Volumetric Analysis
No full textPurpose: The extraction of a tooth is followed by hard and soft tissue changes that can compromise implant placement. The aim of the present retrospective study was to compare the clinical and radiographic outcomes of different ridge preservation procedures based on the use of leukocyte and platelet-rich fibrin (L-PRF). Materials and Methods: The study population consisted of all patients who had undergone surgery from January 1, 2017 to January 1, 2018 for alveolar ridge preservation on single posterior teeth using 3 clinical protocols: L-PRF alone, L-PRF mixed with a bone xenograft, and bone xenograft alone. Clinical and radiographic measures were recorded preoperatively and at 6 months postoperatively to determine the horizontal and vertical ridge resorption. Results: A total of 45 patients were included in the present study. All the surgeries were performed successfully, and no intraoperative complications developed. The L-PRF group experienced significantly greater horizontal and vertical bone resorption. The L-PRF plus bone xenograft group had less vertical and horizontal bone resorption than the bone xenograft alone group. Statistically significant differences in postoperative pain and wound healing were observed, with the bone xenograft alone group, in particular, having higher values for pain and experiencing delayed wound healing. Conclusions: Within the limitations of the present retrospective study, the use of a bone xenograft alone or L-PRF combined with a bone xenograft to perform alveolar ridge preservation procedures significantly limited bone resorption
Xenogeneic collagen matrix versus connective tissue graft for soft tissue augmentation at immediately placed implants: a prospective clinical trial
No full textThe advantages of immediate implant placement for patients include a reduced number of surgical procedures and a shorter overall treatment time. Disadvantages include a higher risk of aesthetic complications. The aim of this study was to compare xenogeneic collagen matrix (XCM) versus a subepithelial connective tissue graft (SCTG) used for soft tissue augmentation in combination with immediate implant placement without provisionalization. Forty-eight patients requiring a single implant-supported rehabilitation were selected and assigned to one of two surgical procedures: immediate implant with SCTG (SCTG group) or immediate implant with XCM (XCM group). Marginal changes in the peri-implant soft tissue and the facial soft tissue thickness (FSTT) were assessed after 12 months. Secondary outcomes included peri-implant health status, aesthetics, patient satisfaction, and perceived pain. All of the implants placed were successfully osseointegrated, resulting in 1-year survival and success rates of 100%. The patients in the SCTG group had a significantly lower mid buccal marginal level (MBML) recession (P = 0.021) and a greater increase in FSTT (P < 0.001) than the patients in the XCM group. Using xenogeneic collagen matrix during immediate implant placement significantly increased FSTT from the baseline, leading to good aesthetic and patient satisfaction results. However, the connective tissue graft yielded better MBML and FSTT results
Angulated titanium bases screw channel abutments for single implant restorations: A systematic review and meta-analysis
No full textPurpose: Screw-retained implant crowns are a common solution to rehabilitate single or multiple edentulous sites. Angulated screw channel (ASC) abutments have been developed as a new system of connection to correct the angulation of the implant and avoid a possible undesired emergence of the access hole. The purpose of this systematic review was to examine available literature related to the effects of ASC abutments in rehabilitating single implant crowns. Methods: A protocol was registered in the PROSPERO database (ID = CRD42022295521). An electronic search of the Cochrane Central Register of Controlled Trials and Trial Protocols, MEDLINE, SCOPUS, and Web of Science was performed up to January 16, 2024. Additionally, a manual search was carried out. The meta-analysis used a fixed or a random effects model, based on the heterogeneity between the studies, focusing on binary and continuous data. A risk of bias assessment was performed (NOS or MOGA et al.) The outcomes assessed were peri-implant marginal bone level, probing pocket depth (PPD), the prevalence of technical and mechanical complications, implant and prosthesis survival rates, and esthetics. Statistical significance was set at p < 0.05. Results: The searches resulted in a total of 10 studies included in the meta-analysis. The mean implant and prosthesis survival rates were respectively 99% (absolute quantity = 243) and 100% (absolute quantity = 239) with non-statistically significant differences observed in single crowns supported by ASC abutments compared to cemented restorations, in terms of marginal bone loss (MBL) (p = 0.22), PPD (p = 0.08), risk of complications (p = 0.53), and esthetics (p = 0.47). Follow-up intervals ranged from 14 days to more than 3 years. Conclusions: Data based on this systematic review suggest that the clinical and radiographic outcomes of single implants restored using ASC are promising if compared to the outcomes relating to screw-retained single crowns
Clinical and radiographic evaluation of implant-supported single-unit crowns with cantilever extensions: A systematic review and meta-analysis
No full textPurposeThe purpose of this systematic review and meta-analysis was to analyze the clinical and radiographic outcomes of patients rehabilitated using a single implant supporting a crown with a cantilever extension or two implants supporting two single crowns.MethodsFollowing the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 guidelines, a systematic review of relevant literature published from 2000 was conducted in the Cochrane Library, Scopus, and MEDLINE databases. Moreover, a manual search was performed. A meta-analysis of the resulting data was carried out. Peri-implant marginal bone level, probing pocket depth, prevalence of technical and mechanical complications, implant survival rate, and prosthesis survival rate were assessed.ResultsThe meta-analysis showed a non-statistically significant change in the peri-implant marginal bone level and probing pocket depth in the cantilever group and revealed a non-significant prevalence of technical complications, showing a 27% rate in the cantilever group. The analysis of the prosthesis survival rate in the cantilever group showed a mean survival rate of 99% while the comparison of the implant survival between the two groups revealed an odds ratio of 0.50.ConclusionsThe use of a single implant supporting a crown with a cantilever extension does not result in lower implant survival rate if compared with two implants supporting two single crowns. Moreover, a high prosthesis survival rate was observed in the cantilever group even if the high prevalence of complications should be carefully considered by the clinician
A Comparison of Guided Bone Regeneration vs. the Shell Technique Using Xenogeneic Bone Blocks in Horizontal Bone Defects: A Randomized Clinical Trial
Full text linkIn cases of severe horizontal atrophy, implant placement requires bone reconstruction procedures. The aim of this randomized controlled trial is to compare the outcomes of bone augmentation with simultaneous implant placement using the shell technique to the outcomes of guided bone regeneration (GBR) in cases of severely horizontal bone atrophy. This study was designed as a monocentric, parallel-group, randomized controlled trial with a six-month follow-up. Among the primary outcomes of this study, peri-implant bone regeneration and peri-implant bone defect closure were selected. Forty-four patients were recruited and equally divided between two groups. In the GRB group, a horizontal regeneration of 2.31 +/- 0.23 mm was observed opposed to a horizontal regeneration of 2.36 +/- 0.17 mm in the shell group (p = 0.87). A volumetric increase was observed in both groups, with an increase of 0.30 +/- 0.12 cm3 in the GBR group and an increase of 0.39 +/- 0.09 cm3 in the shell group, highlighting a significant difference between the two groups (p = 0.02). In conclusion, bone augmentation with simultaneous implant placement using the shell technique or guided bone regeneration in horizontal bone atrophy are both predictable therapeutic options
Influence of Immediate Implant Placement and Provisionalization with or without Soft Tissue Augmentation on Hard and Soft Tissues in the Esthetic Zone: A One-Year Retrospective Study
Full text linkThe purpose of this clinical research was to evaluate peri-implant marginal changes around immediate implants placed either with the application of SCTG or XCM or without soft tissue grafting. A total of 48 patients requiring a single implant-supported restoration in the anterior jaw were selected for inclusion. Three surgical procedures were performed, as follows: type 1 implant with subepithelial connective tissue graft (SCTG), type 1 implant with xenogenic collagen matrix (XCM), and type 1 implant without soft tissue augmentation (NG) (control group). The marginal change of peri-implant soft tissue, facial soft tissue thickness (FSTT), peri-implant health status, esthetics, and patient satisfaction were assessed at one year after surgery. All of the placed implants showed a survival rate of 100%. No significant differences in FSTT were recorded between the SCTG group and the XCM group after treatment (P>0.05), while the NG group presented a significant difference (P<0.05). Patients in the NG group lost significantly more in the buccal marginal level than did patients in the SCTG group and those in the XCM group (P<0.05). The favourable success rate recorded in all groups confirmed immediate tooth replacement as a choice of treatment for a missing anterior single tooth. The NG group presented significant changes of FSTT and buccal marginal level, while XCM constituted a viable alternative to SCTG
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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