1,721,001 research outputs found
Flapless surgery and immediately loaded implants: a retrospective comparison between implantation with and without computer-assisted planned surgical stent
No full textComputer planned flapless surgery and immediate loading are the most recent topics in implantology. One new computer-planned implant system uses a three-dimensional parallelometer able to transfer the implant position from the virtual project to the master model. The aim of this study was to verify if the new medical device gives an advantage in term of implant failures and/or crestal bone remodeling.A retrospective study was planned to analyze a series of 193 immediately loaded fixtures inserted by means of flapless surgery. From those sixty six implants were inserted with computer planning whereas 127 were inserted "free-hand". Several variables related to patient, anatomy, implant, surgery and prosthesis were investigated. To detect the clinical outcome implant' failure and peri-implant bone resorption were considered. Kaplan-Meier algorithm and Cox regression were then performed to detect those variables statistically associated with the clinical outcome.Implant length and diameter ranged from 10 to 16 mm and from 3.75 to 6.0 mm, respectively. Implants were inserted to replace 46 incisors, 30 cuspids, 75 premolars and 42 molars. The mean follow-up period was 15 months. Seven implants were lost (survival rate 96.4\%) but no studied variable has a statistical impact on failures. On the contrary, implants inserted in sites with completed bone healing, wide diameter fixtures and implants inserted in totally edentulous jaw had a significantly lower crestal bone resorption. The other variables (age, gender, upper/lower jaws, tooth site, implant' type and length, number of prosthetic units antagonist condition) did not have impact on crestal remodeling.Computer-planned and cast model transferred implantology is a reliable technology that provides a slightly higher clinical outcome than "free hand" technique at least in healed sites, wider implants and totally edentulous jaws
I mezzi di contrasto intravascolari organo-iodati:caratteristiche chimico-fisiche, indicazioni e controindicazioni
No full textLibro edito per conto della Società Italiana di Radiologia Medic
Comparison between implants inserted into piezo split and unsplit alveolar crests
No full textPURPOSE: Piezoelectric surgery (PES) uses a modulated ultrasonic frequency that permits highly precise and safe hard tissue cutting. A retrospective study on a series of spiral family implants inserted with or without PES split crest was performed to verify if implants inserted into crests split using PES have a comparable outcome to those inserted into unsplit bone. MATERIAL AND METHODS: In the period from May 2004 to November 2007, 86 patients (55 women and 31 men, median age 53 yrs) were operated on and 234 spiral family implants were inserted. Among these, 21 were inserted into PES split crest. Mean follow-up was 13 months (3 to 35 months). The Kaplan-Meier algorithm was used to compare the 2 groups in survival and clinical success (ie, decreased bone resorption around implant neck). RESULTS: Only 9 of 234 implants were lost (ie, survival rate 96.2\%), all of which belonged to the unsplit group but no statistical difference was demonstrated. To detect if PES split crest produces a better clinical outcome in comparison with fixtures inserted into unsplit alveolar ridges, crestal bone loss was compared in the remaining loaded implants (234--9 lost--5 not prosthetized = 220). No statistical significant difference was detected by comparing implants inserted into PES split crests with untreated alveolar ridges, although a better trend was visible for fixtures inserted into PES split crests. CONCLUSION: PES split crests provide several advantages and clinical outcomes that are not worse in terms of bone remodeling, if compared with standard procedures
Bone platform switching: a retrospective study on the slope of reverse conical neck
No full textObjective: Bone platform switching results in an inward bone ring in the coronal part of an implant that is in continuity with the alveolar bone crest. Bone platform switching is achieved by using a dental implant with a reverse conical neck (RCN). A retrospective study was performed to determine the impact of RCN on crestal bone remodeling (CBR). Method and Materials: A series of 191 implants with the same morphology, but three slopes of RCN, were evaluated. Lost implants and CBR around implants still in place at the end of the follow-up were considered to investigate those variables potentially associated with the clinical outcome. Radiographic examinations were performed for each implant before surgery and at the end of the follow-up to detect the degree of CBR. Time-dependent cutoff values were used to select implants with higher CBR. These implants were considered unsuccessful. The Kaplan-Meier algorithm was applied to detect those variables potentially associated with the clinical outcome (ie, lost implants or implants with higher CBR). Results: Only 5 of 191 implants were lost (survival rate 97.4\%). No statistical differences were detected among the studied variables by using lost implants. Conclusions: Although no statistical differences were detected among the three types of implants, the data seem to indicate a correlation between CBR and the slope of the RCN, with a better outcome for implants with a more angulated RCN. (Quintessence Int 2010;41:35-40)
Spiral family implants inserted in postextraction bone sites
No full textPURPOSE: In the last 2 decades, several investigators have reported immediate placement of dental implants into extraction sockets achieving excellent results with a 2-stage surgical procedure. Recently, immediate loading has become an emerging technique as it has been documented to be a successful and a time saving procedure. As regard, few reports are available for the possibility of immediate/early loading of implants placed in fresh extraction sockets. In addition, they are based on limited series with short follow-up. Thus, we decided to perform a retrospective study on a series of postextractive spiral family implants (SFIs). MATERIALS AND METHODS: In the period May 2004 to November 2007, 133 SFIs were inserted in fresh extraction sockets. The mean follow-up was 12 months. Several host-, surgery-, and implant-related factors were investigated and Kaplan-Meier algorithm and Cox regression were used to detect those variables associated with the clinical outcome. RESULTS: Because only 7 of 133 implants were lost (i.e., survival rate, 94.7\%) and no statistical differences were detected among the studied variables, no, or reduced, marginal bone loss was considered as an indicator of success rate to evaluate the effect of several host-, surgery-, and implants-related factors. Also, in this case no variable has impact on clinical outcome. CONCLUSION: It was demonstrated that postextractive SFIs have a high survival and success rate that are similar to those reported in previous studies of 2-stage procedures or in immediate loading implants inserted in healed bone
Platform switching and bone platform switching
No full textBone platform switching involves an inward bone ring in the coronal part of the implant that is in continuity with the alveolar bone crest. Bone platform switching is obtained by using a dental fixture with a reverse conical neck. A retrospective study was performed to evaluate the effectiveness of conventional vs reverse conical neck implants. In the period between May 2004 and November 2007, 86 patients (55 females and 31 males; median age, 53 years) were operated and 234 implants were inserted: 40 and 194 were conventional vs reverse conical neck implants, respectively. Kaplan-Meier algorithm and Cox regression were used to detect those variables associated with the clinical outcome. No differences in survival and success rates were detected between conventional vs reverse conical neck implants alone or in combination with any of the studied variables. Although bone platform switching leads to several advantages, no statistical difference in alveolar crest resorption is detected in comparison with reverse conical neck implants. We suppose that the proximity of the implant abutment junction to the alveolar crestal bone gives no protection against the microflora contained in the micrograph. Additional studies on larger series and a combination of platform switching and bone platform switching could lead to improved clinical outcomes
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
Spiral implants bearing full-arch rehabilitation: analysis of clinical outcome
No full textAbstract Background: A spiral implant is a conical internal helix implant with a variable thread design which confers the characteristic of self drilling, self tapping and self bone condensing. Reports have reported the effectiveness of this type of implants in several clinical situations. However, because there are no reports that specifically focus on one of the biggest challenges in oral rehabilitation, i.e. the full arch rehabitation, it was decided to perform a retrospective study.Materials and Methods: The study population was composed of 23 patients (12 females and 11 males, median age 57 years) for evaluation and implant treatment between January 2005 and June 2009. 206 Spiral family implants (SFIs) were inserted with a mean post loading follow-up of 23 months. Several variables were investigated: demographic (age and gender), anatomic (maxilla and mandible, tooth site), implant (type, length and diameter), surgical (surgeon, post-extractive, flapless technique, grafts) and prosthetic (implant/crown ratio, dentition in the antagonist arch, type of loading and CT planning) variables. Implant loss and peri-implant bone resorption were evaluated. Univariate and multivariate test were performed.Results: Survival and success rates were 97.1 and 82.5\%, respectively. Only implant length and implant/crown ratio were statistical significance in determining a better clinical outcome.Conclusion: In conclusion, SFIs are a reliable tool for most difficult cases of oral rehabilitation. No differences were detected among implant type. Length and implant/crown ratio can influence the crestal bone resorption with better result for longer fixtures and an higher implant/crown ratio. In addition banked bone derived from living donors can be used to restore alveolar ridge augmentation without adverse effects. Finally, flapless and CT-planned surgery did not significant increases the clinical outcome in most complex rehabilitation
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