This research strives to develop and optimize a dental implant by carefully considering square thread designs with varying thread dimensions in order to obtain the most optimal shape. Finite element analysis (FEA) was incorporated with numerical optimization methods to produce a mathematical model in this research project. Utilizing response surface methodology (RSM) and design of experiments (DOE), researchers scrutinized the critical parameters of dental implants, resulting in a streamlined optimal shape. Under optimal conditions, the predicted values were held against the simulated results for a comparative analysis. Dental implant testing, using a one-factor RSM design and a 450 N vertical compressive load, demonstrated that a thread depth-to-width ratio of 0.7 yielded the least von Mises and shear stress. When considering the reduction of von Mises and shear stress, the buttress thread shape proved superior to square threads. Consequently, the calculated thread parameters were established as 0.45 times the pitch for depth, 0.3 times the pitch for width, and a 17-degree angle. The implant's consistent diameter enables the effortless interchangeability of 4-mm diameter abutments.
This research aims to quantify the effect of cooling on the reverse torque values produced when installing various abutments in bone-level and tissue-level implants. The hypothesis under scrutiny, the null hypothesis, proposed no divergence in reverse torque values between cooled and uncooled implant abutment screws. Implantation of bone-level and tissue-level implants (Straumann, 36 implants in each group) occurred within synthetic bone blocks, separated into three categories (12 implants per group): titanium base abutments, cementable abutments, and abutments designed for screw-retained restorations. All abutment screws were subjected to a torque measurement of 35 Ncm. Before releasing the abutment screw in half of the implant cases, a dry ice rod was used to treat the abutments close to the implant-abutment junction for exactly 60 seconds. The implant-abutment pairs which were not yet removed were not cooled. The maximum reverse torque values were definitively ascertained and recorded via a digital torque meter. GSK1016790A Three cycles of the tightening-releasing-cooling procedure were completed for each implant within the test groups, yielding eighteen reverse torque values per implant group. The influence of cooling parameters and abutment variations on the collected data was assessed using a two-way analysis of variance (ANOVA). Group comparisons were assessed using post hoc t-tests, with a significance level of .05 as the criterion. To control for the influence of multiple testing, post hoc test p-values were adjusted using the Bonferroni-Holm method. Analysis of the data led to the rejection of the null hypothesis. GSK1016790A The interplay of cooling and abutment type was found to have a profound and statistically significant effect on the reverse torque values of bone-level implants (P = .004). The study found no tissue-level implants, a finding that was statistically significant (P = .051). Cooling bone-level implants resulted in a decrease in reverse torque, specifically a drop from an average of 2031 ± 255 Ncm to an average of 1761 ± 249 Ncm. A substantial difference in mean reverse torque values was observed between bone-level and tissue-level dental implants, with bone-level implants showing significantly higher values (1896 ± 284 Ncm) than tissue-level implants (1613 ± 317 Ncm) (P < 0.001). Cooling the implant abutment resulted in a marked decrease in reverse torque values measured in bone-level implants, and thus, advocates for its application as a pretreatment before attempting to remove a jammed implant part.
We aim to determine if preventive antibiotic therapy decreases sinus graft infection and/or dental implant failure rates in maxillary sinus elevation procedures (primary outcome), and to establish the best antibiotic protocol for this purpose (secondary outcome). In pursuit of relevant material, a search was conducted across MEDLINE (via PubMed), Web of Science, Scopus, LILACS, and OpenGrey databases, with the timeframe constrained between December 2006 and December 2021. English-language comparative clinical trials, encompassing both prospective and retrospective designs, with a minimum of 50 patients, were included. Animal studies, systematic reviews, meta-analyses, narrative literature reviews, books, case reports, letters to the editor, and commentaries formed part of the exclusion criteria for this study. Independent review by two reviewers was undertaken for the assessment of the identified studies, data extraction, and evaluation of potential bias. Required authors were contacted. GSK1016790A Descriptive methods were used to report the collected data. Twelve studies were deemed eligible for inclusion based on the criteria. In the sole retrospective study that contrasted antibiotic use with no use, no significant difference in implant failure was detected; however, data regarding sinus infection rates were unavailable. The sole randomized controlled trial that contrasted antibiotic administration schedules (the day of surgery versus seven additional postoperative days) did not discover any statistically significant difference in the rates of sinus infections between the comparative groups. The current body of evidence lacks the strength to advocate for or against the use of prophylactic antibiotics in sinus elevation procedures, nor does it pinpoint a superior surgical protocol.
To evaluate the accuracy (measured by linear and angular deviation) of dental implants installed using computer-aided surgery, considering the influences of surgical procedures (fully guided, partially guided, and non-guided placement), bone density (classifications D1 to D4), and support type (tooth-borne versus mucosa-borne). A total of thirty-two mandible models, comprised of sixteen partially edentulous and sixteen edentulous specimens, were constructed from acrylic resin. Each model was precisely calibrated to a different bone density, ranging from D1 to D4. Mguide software facilitated the placement of four implants in each acrylic resin mandible. A total of 128 implants were placed, divided into groups based on bone density (D1-D4, each with 32 implants), the degree of surgical guidance (80 fully guided [FG], 32 half-guided [HG], 16 freehand [F]), and support type (64 tooth-supported and 64 mucosa-supported). The planned and actual three-dimensional positions of the implanted components were compared using linear and angular measurements derived from preoperative and postoperative CBCT scans, to assess deviations in linear, vertical, and angular orientations. Linear regression models and parametric tests were used to assess the effect. Regional analyses of linear and angular discrepancy (neck, body, and apex) pointed to the technique as the most influential variable. Bone type, while exhibiting a degree of predictive ability, played a less crucial role. Nevertheless, both factors demonstrated significant predictive value. Completely edentulous models often exhibit a marked escalation in these discrepancies. Linear deviation increases, according to regression models, between FG and HG techniques. At neck level, buccolingual deviations increase by 6302 meters, while mesiodistal deviations at the apex increase by 8367 meters. A cumulative increase is observed when the HG and F techniques are juxtaposed. The effect of bone density, as modeled by regression analyses, showed linear discrepancies rising by a range of 1326 meters axially to 1990 meters at the implant's apex buccolingually, for each reduction in density (D1 to D4). According to this in vitro study, the highest predictability for implant placement is observed in dentate models possessing high bone density and employing a surgically guided technique that is completely controlled.
The proposed study seeks to evaluate the hard and soft tissue response and mechanical durability of screw-retained zirconia crowns layered and bonded to titanium nitride-coated titanium (TiN) CAD/CAM abutments, themselves supported by implants, at 1- and 2-year follow-up appointments. One hundred two free-standing, implant-supported layered zirconia crowns were fabricated for 46 patients. Bonded to their associated abutments within a dental laboratory, they were subsequently delivered as single-piece, screw-retained crowns. The one-, two-, and baseline-year datasets were compiled to include pocket probing depth, bleeding upon probing, marginal bone levels, and any mechanical problems. Among the 46 patients examined, 4, possessing one implant each, were not observed for follow-up. The analysis cohort did not include these patients. Of the 98 remaining implants, 94 and 86 had soft tissue measurements taken at one and two years, respectively, following schedule disruptions due to the global pandemic. The average buccal and lingual pocket probing depths were 180/195mm and 209/217mm, respectively. According to the study protocol, probing at one and two years yielded mean bleeding values of 0.50 and 0.53, respectively, these results signifying a level of bleeding somewhere between no bleeding and a slight spot of bleeding. Radiographic evaluation was possible for a sample of 74 implants at the end of year one and expanded to 86 implants by year two. The bone level's final position, with reference to the initial point, was mesially +049 mm and distally +019 mm at the end of the study. A minor crown margin misalignment was documented in one unit (1%), highlighting a mechanical complication. Porcelain fractures were identified in 16 units (16%), while preload reductions, falling below 5 Ncm (under 20% of original) were detected in 12 units (12%). The biologic and mechanical integrity of ceramic crowns, bonded to CAD/CAM screw-retained abutments employing angulated screw access, was deemed high, exhibiting overall bone gain, remarkable soft tissue health, and only marginal mechanical issues, limited to minor porcelain fractures and a clinically insignificant drop in preload.
The investigation focuses on evaluating the marginal accuracy of soft-milled cobalt-chromium (Co-Cr) in tooth/implant-supported restorations, comparing it to other construction techniques and restorative materials.