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1.
Priscilla Medina-Sotomayor Agustín Pascual-Moscardo Isabel Camps A 《The Journal of prosthetic dentistry》2019,121(5):811-820
Statement of problem
The accuracy of digital scanners is acceptable for scanning a complete dental arch. However, whether that accuracy is sufficient for only 1 tooth within the dental scan of a complete dental arch is unclear.Purpose
The purpose of this in vitro study was to evaluate and compare the accuracy of 4 intraoral scanners on a complete dental arch and on prepared teeth digitally isolated from the digital scan in terms of trueness and precision.Material and methods
A model of a complete dental arch with tooth preparations was scanned 40 times with each of the 4 digital scanners. Their accuracy was evaluated by using 3-dimensional (3D) software to compare the test models with a highly accurate reference model. The data were digitally processed to isolate the prepared teeth and evaluate them in the same way. The data were statistically analyzed using the Levene test and the Tamhane's T2 test (α=.05).Results
In scans of a complete dental arch, the True Definition scanner had the best accuracy values, followed by TRIOS, iTero, and Omnicam. For prepared teeth isolated from the dental arch, both True Definition and TRIOS had the best values, followed by iTero and Omnicam.Conclusions
In both long-span scans of the complete dental arch and isolated prepared teeth, the True Definition scanner had the greatest accuracy, closely followed by TRIOS. 相似文献2.
Najla Chebib Nicole Kalberer Murali Srinivasan Sabrina Maniewicz Thomas Perneger Frauke Müller 《The Journal of prosthetic dentistry》2019,121(4):623-630
Statement of problem
Simplified edentulous jaw impression techniques have gained popularity, while their validity has not yet been evaluated.Purpose
The purpose of this clinical study was to compare the trueness of maxillary edentulous jaw impressions made with irreversible hydrocolloid (ALG), polyvinyl siloxane (PVS), PVS modified with zinc oxide eugenol (ZOE) (PVSM), and an intraoral scanner (TRI) with a conventionally border-molded ZOE impression (control).Material and methods
Twelve edentulous maxillary impressions were made with the impression techniques. The analog impressions were scanned using a laboratory scanner, imported into 3-dimensional comparison software, and superimposed against the corresponding control. Trueness was evaluated by calculating the effective deviation known as root mean square (RMS) for the entire surface (ES) and for specific regions of interest such as peripheral border, inner seal, midpalatal suture, ridge, and posterior palatal seal. The secondary outcomes for this study were the patients' perception of the impression techniques. Statistical analyses with the Wilcoxon tests were carried out (α=.05).Results
For ES, significant differences were found when comparing ALG (1.21 ±0.35 mm) with PVS (0.75 ±0.17 mm; P=.008), PVSM (0.75 ±0.19 mm; P=.012), and TRI (0.70 ±0.18 mm; P=.006) but not among the other groups. Significant differences were found for peripheral border when comparing ALG (2.03 ±0.55 mm) with PVS (1.12 ±0.32 mm; P=.006), PVSM (1.05 ±0.29 mm; P=.003), and TRI (1.38 ±0.25 mm; P=.008), as well as TRI and PVSM (P=.028). Significant differences were also found for inner seal when comparing ALG (0.74 ±0.36 mm) with PVSM (0.52 ±0.13 mm; P=.041), as well as TRI (0.8 ±0.25 mm) versus PVS (0.56 ±0.14 mm; P=.005) and PVSM (P=.005). The difference at the ridge was significant when comparing PVS (0.18 ±0.07 mm) with PVSM (0.28 ±0.19 mm; P=.015) but not among the other groups. A significant difference was also found for posterior palatal seal when comparing PVS (0.55 ±0.41 mm) with PVSM (0.60 ±0.43 mm; P=.034). Patient perceptions showed significantly better satisfaction scores for ALG (1.83 ±2.03) and PVS (3.17 ±2.40) than for TRI (4.08 ±2.71), PVSM (4.58 ±2.35), and ZOE (6.83 ±1.75).Conclusions
Edentulous impressions made with PVS, PVSM, and TRI had similar deviations and may yield clinically acceptable results. Irreversible hydrocolloids are contraindicated for definitive impression making in completely edentulous jaws. 相似文献3.
Nynke Lie Hans-Albert Merten Kensuke Yamauchi Jörg Wiltfang Peter Kessler 《Journal of cranio-maxillo-facial surgery》2019,47(3):454-460
Introduction
In edentulous patients the form and size of the maxillary sinus vary greatly. Therefore sinus floor augmentation is a standard procedure for implantological purposes. As the sinus membrane cannot be characterized as periosteum, various augmentation materials are used.Hypothesis
an artificially generated space underneath the sinus membrane in the floor of the sinus will lead to spontaneous callus forming and a stable bony consolidation without augmentation material.Methods
Ten edentulous patients with highly atrophic maxillae were selected. Augmentation of the sinus floor was carried out in a split-mouth study design: On one side a combination of autogenous and xenogenous bone was used, and on the contralateral side a sinus membrane elevation was performed without using any substitutes. After a 6-month interval bone specimens from the test regions were harvested during implant placement.Results
Clear histological evidence of new bone formation was found in all human bone specimens. An active de-novo bone formation process could be proven by the presence of Haversian systems (osteons) displaying osteoblastic and osteoclastic activity.Conclusion
In the maxillary sinus of edentulous patients a spontaneous callus-derived de-novo bone formation is possible by elevating the sinus membrane without using augmentation materials. 相似文献4.
Mikel Iturrate Harkaitz Eguiraun Olatz Etxaniz Eneko Solaberrieta 《The Journal of prosthetic dentistry》2019,121(3):447-454
Statement of problem
Obtaining reliable digital scans of edentulous patients is challenging because of the absence of anatomic landmarks/geometric variations along the dental arch. Whether adding an auxiliary geometric device (AGD) will improve scanning is unclear.Purpose
The purpose of this in vitro study was to analyze the accuracy of complete-arch digital scans of completely edentulous arches by placing a consumable AGD.Material and methods
A stainless-steel model of the maxilla of a completely edentulous arch with 4 implants was built. The model was scanned using a reference industrial scanner as the control and using 3 intraoral scanners (True Definition [3M ESPE], TRIOS 3 [3Shape A/S], and iTero [Align Technology, Inc]). Each intraoral scanner was used 10 times without the AGD in place and 10 more times with the AGD fixed on the model. Accuracy in terms of trueness and precision was established by comparing 5 reference distances with or without the AGD in place. A software program for analyzing 3D data was used to measure these 5 distances, and a data analysis software program was used for statistical and measurements analysis (α=.05).Results
Significant differences (P<.05) were found in all reference distances for trueness and in 4 of the 5 reference distances for precision depending on whether the AGD had been used or not. Without the AGD in place, trueness ranged from 21 ±16 μm in the shortest reference distance to 125 ±80 μm in the largest reference distance. With the AGD in place, trueness ranged from 11 ±8 μm in the shortest reference distance to 64 ±51 μm in the largest reference distance. Precision ranged from 18 ±14 μm in the shortest reference distance to 84 ±74 μm in the largest reference distance without the AGD and from 7 ±7 μm in the shortest to 63 ±46 μm in the largest with it.Conclusions
Complete-arch digital scans of edentulous jaws are more accurate when an AGD is used to resolve the lack of anatomic landmarks. An additional advantage is that the use of the AGD allows for a more fluent scanning process. 相似文献5.
Francesco Saverio Ludovichetti Flávia Zardo Trindade Gelson Luis Adabo Luca Pezzato Renata Garcia Fonseca 《The Journal of prosthetic dentistry》2019,121(5):866.e1-866.e8
Statement of problem
The effect of clinical adjustments on the strength of cemented computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic materials under aging challenge is unclear.Purpose
The purpose of this in vitro study was to assess the surface roughness and fracture resistance (with or without mechanical aging) of cemented CAD-CAM monolithic materials submitted to grinding and polishing procedures.Material and methods
Disks of Lava Ultimate, Vita Enamic, crystallized Vita Suprinity, and IPS e.max CAD were analyzed for roughness after polishing by using silicon carbide papers (Lava Ultimate and Vita Enamic) or glazing (IPS e.max CAD and Vita Suprinity) (control), after grinding by using 30-μm grit diamond rotary instruments, and after grinding and polishing by using a polishing kit. For fracture resistance, a simplified trilayer model consisting of a restorative disk, an epoxy resin disk, and a steel ring was used. The bonded trilayer disks received the same treatments described for the roughness analysis. Half of the specimens underwent mechanical aging for 1×106 cycles. All specimens were loaded until failure. The Weibull modulus was calculated.Results
The IPS e.max CAD and Vita Suprinity showed the highest roughness after grinding and the lowest at baseline. For the Lava Ultimate and Vita Enamic, polishing provided lower roughness than at baseline. Grinding, followed or not by polishing, and mechanical aging did not adversely affect the fracture resistance or the reliability of the materials.Conclusions
Polishing did not recover the initial surface roughness of the glass-ceramic materials. Fracture resistance was not affected by grinding, followed or not by polishing, even after mechanical aging. 相似文献6.
Nina Riera-Punet Jordi Martinez-Gomis Carla Zamora-Olave Eva Willaert Maria Peraire 《The Journal of prosthetic dentistry》2019,121(4):631-636
Statement of problem
About 10% of patients with amyotrophic lateral sclerosis (ALS) are candidates for oral treatment specifically because of traumatic injuries in the lips, cheeks, or tongue due to self-biting. However, patients with ALS have a prevalence of temporomandibular disorder (TMD) similar to that in the general population.Purpose
The purpose of this case-series study was to determine the degree of satisfaction of patients with ALS with an oral appliance for managing oral self-biting lesions or symptoms related to TMDs. This study also assessed the degree of improvement of the chief complaint and the compliance with and adverse effects of this treatment.Material and methods
Eleven patients with ALS who sought oral treatment because of oral self-biting or TMD-related symptoms were included. A custom complete-coverage acrylic resin device was fabricated and fitted to each participant. A follow-up visit was planned for 3 months after the placement of the oral appliance, at which point the patients would rate the degree of improvement or worsening of the chief complaint and their degree of satisfaction with the treatment. A 1-sample t test was used to assess whether the degree of improvement of the chief complaint was significant.Results
Participants reported a mean of 61% (95% confidence interval [CI] 38% to 84%) improvement of the chief complaint and a mean of 84% (95% CI 72% to 97%) satisfaction with the treatment. The mean rate of compliance was 62% (95% CI 40% to 84%) of the recommended time, and only a few adverse effects were reported.Conclusions
Participants with ALS were highly satisfied with the use of an oral appliance to manage oral self-biting or TMD-related symptoms. Adherence to this treatment was high, and no major adverse effects were observed. 相似文献7.
Guilherme Berger Luiz Felipe de Oliveira Pereira Evelise Machado de Souza Rodrigo Nunes Rached 《The Journal of prosthetic dentistry》2019,121(5):865.e1-865.e7
Statement of problem
Evidence regarding the effect of different glass fiber reinforcement designs on the biomechanical behavior of implant-supported overdentures is lacking.Purpose
The purpose of this finite element analysis was to analyze the stress distribution in an implant-supported overdenture reinforced with a cast metal reinforcement bar and 4 different designs of unidirectional glass fiber to minimize the risk of denture base fracture.Material and methods
A 3D edentulous mandible incorporating an implant-supported overdenture model without reinforcement (control, CT) or reinforced with 1 cast metal bar reinforcement (CM) was placed over the top of the implants and 4 unidirectional glass fiber reinforcements. The glass fiber bundle was placed over the top of the implants (GF), or 2 bundled halves were placed over the top (GO) of, between (GB), or distal (GD) to implants. Three patterns of occlusal loading were simulated: L1, all artificial teeth loaded in the long axis; L2, all left-side teeth loaded in the long axis; and L3, posterior left-side teeth loaded obliquely (45 degrees).Results
Under L1 and L3, the tensile stresses were higher for CT, GD, and GO and lower for GF and CM. Under L2, no differences were seen between groups. Stresses were concentrated on the periphery of the O-ring connector, on the basal area, and on the middle-lingual region of the overdenture.Conclusions
Reinforcements placed in the middle region and over the top of the implants provided better load distribution. Unidirectional glass fiber behaved as cast metal when used to reinforce the implant-supported overdenture. 相似文献8.
Yiqin Fang Xueyin An Seung-Mi Jeong Byung-Ho Choi 《The Journal of prosthetic dentistry》2019,121(5):836-842
Statement of problem
Implant placement in the anterior regions is often challenging because of limited space and bone volume availability.Purpose
The purpose of this clinical study was to investigate the accuracy of computer-guided surgery with a long drill key to place implants in the anterior regions.Material and methods
Computer-guided implant surgery was performed for 32 participants requiring implants in anterior regions. The procedure involved using a 12-mm-long drill key to guide the 2.0-mm-diameter drill. Deviations between the planned and actual implant positions were evaluated by using cone beam computed tomography (CBCT) scans obtained before and after surgery. A t test was used for comparisons between the planned and placed implants and to determine the influence of the arch (maxilla/mandible) and time (immediate/delayed) on accuracy.Results
A total of 40 implants (20 implants in the maxilla and 20 implants in the mandible) were placed. The mean linear deviation was 0.46 mm (range, 0 to 1.15 mm) for the implant shoulder and 0.67 mm (range, 0.14 to 1.19 mm) for the implant apex. The mean angular deviation was 1.40 degrees (range, 0.30 to 2.57 degrees). The mean depth deviation was 0.15 mm (range, 0.10 to 0.82 mm).Conclusions
This clinical study showed that the accuracy of computer-guided implant placement may be enhanced by using a long drill key and may thus enable more accurate implant placement in anterior regions. 相似文献9.
Alex Leo Sequeira Aparna I. Narayan Vinu Thomas George 《The Journal of prosthetic dentistry》2019,121(5):843-847
Statement of problem
Variation in the baseline mechanical properties of polyamide thermoplastic polymers used in the fabrication of prosthetic dental appliances and the effects of nonaldehyde disinfectants on the mechanical properties of these polymers are unclear.Purpose
The purpose of this in vitro study was to compare the flexural and impact strengths of 2 flexible denture materials (Valplast and Sunflex) and evaluate the effect of 24-hour immersion in nonaldehyde disinfectant (Perform) on their flexural and impact strengths.Material and methods
Of 48 specimens of Valplast and Sunflex, half were immersed in nonaldehyde disinfectant solution containing the active ingredient 2% peroxymonosulfate for 24 hours. Flexural and impact strengths were measured using a universal testing machine. The Student t test with Bonferroni correction was used (α=.008).Results
For the Valplast group, the mean ±standard deviation flexural strength was 27.8 ±0.57 MPa, and the impact strength was 3.5 ±0.98 kJ/m2. For the Sunflex group, the mean flexural strength was 57.4 ±4.09 MPa, and the impact strength was 6.0 ±3.11 kJ/m2. Sunflex showed greater flexural strength (P≤.001) and impact strength (P=.001) than Valplast. A significant increase in the impact strength (P≤.001) but not in the flexural strength of Valplast was observed after exposure to the disinfectant solution. Immersion disinfection had no significant effect on the strength of Sunflex.Conclusions
The flexural and impact strengths of Sunflex were significantly greater than those of Valplast. Immersion disinfection with peroxymonosulfate had no significant effect on Sunflex but increased the impact strength of Valplast. 相似文献10.
Nawakamon Suriyan Lertrit Sarinnaphakorn George R. Deeb Sompop Bencharit 《The Journal of prosthetic dentistry》2019,121(3):411-416
Statement of problem
Conventional guided implant surgery promises clinical success through implant placement accuracy; however, it requires multiple drills along with surgical sleeves and sleeve adapters for the horizontal and vertical control of osteotomy drills. This results in cumbersome surgery, problems with patients having limited mouth opening, and restriction to specific drill or implant manufacturers. A protocol for using trephination drills to simplify guided surgery and accommodate multiple implant systems is introduced.Purpose
The purpose of this clinical study was to evaluate the accuracy of implant placement using this novel guided trephine drill protocol with and without a surgical sleeve.Material and methods
Intraoral scanning and preoperative cone beam computed tomography (CBCT) scans were used for implant treatment planning. Surgical guides were fabricated using stereolithography. Implant surgery was performed using the guided trephination protocol with and without a surgical sleeve. Postoperative CBCT scans were used to measure the implant placement deviations rather than the implant planning position. Surgical placement time and patient satisfaction were also documented. One-tailed t test and F-test (P=.01) were used to determine statistical significance.Results
Thirty-five implants in 17 participants were included in this study. With a surgical sleeve, implant positional deviations were 0.51 ±0.13 mm vertically, 0.32 ±0.10 mm facially, 0.11 ±0.11 mm lingually, and 0.38 ±0.13 mm mesially. Without a surgical sleeve, implant positional deviations were 0.58 ±0.27 mm vertically, 0.3 ±0.14 mm facially, 0.39 ±0.16 mm lingually, and 0.41 ±0.12 mm mesially. No statistically significant difference was found between the 2 protocols (P>.01), except that the sleeve group had greater vertical control precision (F-test, P=.006), reduced placement time, and the time variation was reduced (t test, P=.003; F-test, P<.001).Conclusions
This trephination-based, guided implant surgery protocol produces accurate surgical guides that permit guided surgery in limited vertical access and with the same guided surgery protocol for multiple implant systems. Guided sleeves, although not always necessary, improve depth control and reduce surgical time in implant placement. 相似文献11.
S.E.C.M. van de Vijfeijken R. Schreurs L. Dubois A.G. Becking 《Journal of cranio-maxillo-facial surgery》2019,47(4):542-547
Purpose
The aim of this study was to evaluate the accuracy of resection templates in cranioplasties in order to facilitate a one-stage resection and cranial reconstruction. Patients and methods: In three cases, cranial resections were combined with direct reconstructions using the principles of computer-aided design, manufacturing, and surgery. The precision of the resection template was evaluated through a distance map, comparing the planned and final result.Results
The mean absolute difference between the planned and actual reconstructed contour was less than 1.0 mm. After 3 years, no clinical signs of infection or rejection of the implants were present. The computed tomography scans showed no irregularities, and the aesthetic results remained satisfactory.Conclusion
One-stage resection and cranial reconstruction using a resection template, control template, and a prefabricated patient-specific implant of poly(ether-ether-ketone) (PEEK) proved to be a viable and safe method. 相似文献12.
Wafa’a R. Al-Magaleh Amal A. Swelem Mohamed H. Abdelnabi Abdulbaset Mofadhal 《The Journal of prosthetic dentistry》2019,121(3):440-446
Statement of problem
The effect of the neutral zone (NZ) technique on different functional aspects (masticatory performance, speech, and muscle activity) has been studied objectively. Subjectively, some studies reported that their participants felt that NZ dentures were more stable, retentive, and comfortable than conventionally fabricated dentures. These studies, however, lacked a measurable assessment scale or a specifically designed questionnaire.Purpose
The purpose of this within-subject, crossover clinical trial was to investigate patient satisfaction levels in edentulous patients after rehabilitation with dentures fabricated using the NZ concept as compared with conventional dentures using a specific, question-oriented patient satisfaction questionnaire.Material and methods
The clinical trial included 52 participants. Each received one set of conventional dentures and another fabricated based on the NZ concept with a 1-month wash-out period. Participants randomly chose 1 of 2 closed opaque envelopes with 2 denture sequences, either conventional then NZ or NZ then conventional. Hence, participants were blinded to the dentures they wore. Patient satisfaction with each denture type was assessed 6 weeks after insertion by a blinded staff member using a 5-scale questionnaire developed for the most important functional aspects (esthetics, masticatory ability, retention, stability, speech, and comfort). The Wilcoxon Signed Rank test was used to compare the satisfaction scores of the 2 denture types (α=.05).Results
Patient satisfaction scores were significantly higher with the NZ dentures than with the conventional dentures in all aspects; P=.001 for question 2 (opinion of denture appearance) and P<.001 for all other questions.Conclusions
NZ dentures offer significantly higher levels of patient satisfaction than conventional dentures in all functional aspects (retention, stability, masticatory ability, and speech) as well as in comfort and appearance. 相似文献13.
Björn Gjelvold Deyar Jallal Hadi Mahmood Ann Wennerberg 《The Journal of prosthetic dentistry》2019,121(3):498-503
Statement of problem
Different factors influence the degree of deviation in dental implant position after computed tomography–guided surgery. The surgical guide–manufacturing process with desktop 3D printers is such a factor, but its accuracy has not been fully evaluated.Purpose
The purpose of this in vitro study was to evaluate the deviation in final dental implant position after the use of surgical guides fabricated from 2 different desktop 3D printers using a digital workflow.Material and methods
Twenty 3D-printed resin models were prepared with missing maxillary premolar. After preoperative planning, 10 surgical guides were produced with a stereolithography printer and 10 with a digital light-processing (DLP) printer. A guided surgery was performed; 20 dental implants (3.8×12 mm) were installed, and a digital scan of the dental implants was made. Deviations between the planned and final position of the dental implants were evaluated for both the groups.Results
A statistically significant difference between stereolithography and DLP were found for deviation at entry point (P=.023) and the vertical implant position (P=.009). Overall lower deviations were found for the guides from the DLP printer, with the exception of deviation in horizontal implant position.Conclusions
The tested desktop 3D printers were able to produce surgical guides with similar deviations with regard to the final dental implant position, but the DLP printer proved more accurate concerning deviations at entry point and vertical implant position. 相似文献14.
Marcela G. Borges Carlos J. Soares Thaís S. Maia Aline A. Bicalho Tarsis P. Barbosa Henara L. Costa Murilo S. Menezes 《The Journal of prosthetic dentistry》2019,121(5):868.e1-868.e8
Statement of problem
Posterior composite restorations may be negatively affected by acidic and colored drinks. Little information is available about the effect of acidic drinks on bulk-fill composite resins.Purpose
The purpose of this in vitro study was to investigate the effect of acidic drinks on the different properties of conventional and bulk-fill composite resins.Material and methods
A conventional composite resin and 2 representative bulk-fill composite resins were used to prepare disk-shaped specimens. The degree of conversion (DC) was monitored by spectroscopy (n=5). The specimens were divided into 5 groups: control, artificial saliva, acai juice, red wine, and Coca-Cola and were maintained for 30 days of challenge (3 periods of 15 min/d). Surface topography parameters were measured by interferometry (n=5). Elastic modulus (E) and Vickers hardness (VH) were determined by microhardness dynamic indentation (n=5). Diametral tensile strength (DTS) was determined at 0.5 mm/min (n=5). Shade matching was evaluated by using the Vitapan Classic Shade Guide. The DC, Sa, Ssk, Sku, Sdq, and DTS were statistically analyzed using 2-way ANOVA, followed by the Tukey HSD tests. E and VH were statistically analyzed by 3-way ANOVA, followed by Tukey HSD tests (α=.05). Shade matching was analyzed with the Kruskal-Wallis test.Results
DC values were similar for the immediate evaluation and after 24 hours, regardless of the composite resin (P<.05). All surface topography parameters increased significantly after the acidic drinks and were greatest for Coca-Cola. The E, VH, and DTS decreased significantly for all composite resins tested (P<.05). Acai juice and red wine produced more surface staining than Coca-Cola.Conclusions
Acidic drinks negatively influenced the physical and mechanical properties of conventional and bulk-fill composite resins. 相似文献15.
Jéssica Marcela de Luna Gomes Cleidiel Aparecido Araújo Lemos Joel Ferreira Santiago Junior Sandra Lúcia Dantas de Moraes Marcelo Coelho Goiato Eduardo Piza Pellizzer 《The Journal of prosthetic dentistry》2019,121(5):766-774.e3
Statement of problem
Consensus is lacking regarding the optimal number of implants for supporting complete-arch prostheses with good survival rates and lower prosthetic complications and marginal bone loss.Purpose
The purpose of this systematic review was to evaluate the influence of the number of implants used for complete-arch prostheses with at least 5 years of follow-up.Material and methods
A search was performed in the PubMed/MEDLINE, Scopus, and Cochrane Library databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria and was registered in The International Prospective Register of Systematic Reviews (CRD42016048468). The following was the population, intervention, comparison, outcome (PICO) question: Does the number of implants influence the longevity of complete-arch prostheses?Results
Nineteen studies including 1006 patients with a mean age of 61.44 years were selected for evaluation. The number of implants per jaw ranged between 2 and 9 in the maxilla, mandible, or both jaws. For implant survival rate in complete-arch prostheses with fewer than 5 implants per jaw, the pooled weighted event rate was 1.4% (I2=25.26%; P=.211) and 4.2% (I2=81.35%; P<.001) for complete arches with more than 4 implants per jaw. For the prosthesis survival rate, the pooled weighted event rate for a complete-arch with fewer than 5 implants per jaw was 1.5% (I2=0%; P=.677) and 9% (I2=17.33%; P=.304) for complete arches with more than 4 implants per jaw. For prosthesis complications for complete arches with fewer than 5 implants per jaw, the pooled weighted event rate was 19.9% (I2=93.5%; P<.001) and 24.5% (I2=88.89; P<.001) for complete arches with more than 4 implants per jaw. The mean marginal bone loss for complete arches with fewer than 5 implants per jaw was 1.22 ±0.49 mm (I2=99.46; P<.001) and 1.46 ±0.46 mm (I2=99.6; P <.001) for more than 4 implants per jaw.Conclusions
The current systematic review indicated no relationship of the number of implants used to support a complete-arch prosthesis with implant survival rate, prosthesis survival rate, prosthesis complications, or marginal bone loss in studies with follow-up periods of between 5 and 15 years. 相似文献16.
Yuehong Fan Gerald N. Glickman Mikhail Umorin Madhu K. Nair Poorya Jalali 《Journal of endodontics》2019,45(5):606-610
Introduction
This study aimed to introduce a novel method using cone-beam computed tomographic (CBCT) imaging and prefabricated grids to guide apical access during endodontic microsurgery and to compare its accuracy with that of the nonguided method.Methods
Forty-two roots from human cadaver jaws were selected. Twenty-one were randomly assigned to the experimental group (grid based) and their contralateral counterparts to the control group (nonguided). Preoperative CBCT images were used to design a drill path that intended to reach the palatal/lingual aspect of the roots without attempting to complete the osteotomy or to resect the entire root end. In the experimental group, prefabricated metal grids used during imaging and surgery acted as a reference in the design and drilling. Postoperative CBCT volumes were superimposed on the preoperative volumes, and the distances between the actual drill paths and the target points were measured. A dichotomized outcome of success versus failure was also recorded and compared. Statistical analysis was performed using the paired t test and Fisher exact test.Results
The mean deviation of the drill paths from the target points was 0.66 mm ± 0.54 mm (mean ± standard deviation) for grid-based drilling and 1.92 mm ± 1.05 mm (mean ± standard deviation) for nonguided drilling (P < .001). Grid-based drilling was on average 1.27 mm (95% confidence interval, 0.81–1.72 mm) closer to the target point than nonguided drilling. The probability of successful drilling was also significantly higher with grids than without grids (P = .02).Conclusions
The proposed method of guided osteotomy and root-end resection using prefabricated grids was more accurate than the nonguided method. 相似文献17.
Lisa A. Lang Sarah E. Hansen Norma Olvera Sorin Teich 《The Journal of prosthetic dentistry》2019,121(4):611-617
Statement of problem
Identifying factors that affect the clinical outcomes of implant therapy is important.Purpose
The purpose of this retrospective study was to determine whether implant location was a factor affecting the complication and failure rates of single-tooth implant-supported restorations in a predoctoral setting.Material and methods
The charts of 431 patients treated with a surgically placed dental implant and restored with a single crown in the predoctoral clinic were analyzed. Data on implant location, type of complication (surgical or prosthetic), and type of failure were collected and analyzed according to implant location using the Fisher Exact Test and Mantel-Haenszel Exact Chi Square Test analysis (α=.05).Results
The charts revealed 158 complications (68 surgical and 90 prosthetic) in 110 patients, and 3.9% of the implants failed. No statistically significant difference was found between the number of surgical complications or prosthetic complications in the maxilla and the mandible (P=.469).Conclusions
Jaw location (maxilla compared with mandible) of the implant had no statistically significant impact on the incidence of surgically or prosthetically related complications. No statistically significant difference was found in overall implant failures, surgical failures, and prosthetic failures between maxillary and mandibular implants. 相似文献18.
Guillermo de la Rosa Castolo Sonia V. Guevara Perez Pierre-Jean Arnoux Laurent Badih Franck Bonnet Michel Behr 《The Journal of prosthetic dentistry》2019,121(3):546.e1-546.e10
Statement of problem
Implant-supported overdentures (IODs) are a treatment option for patients with complete edentulism. However, this treatment increases the possibilities of peri-implant complications, characterized by inflammation or partial loss of surrounding hard and soft tissues.Purpose
The purpose of this finite element analysis study was to evaluate the mechanical performance of different bar-IOD designs under different clinical configurations by comparing the stress and strain distribution on the bone during secondary stabilization.Material and methods
A finite element model of the mandible representing a patient with complete edentulism was developed. Different designs of bar-IODs were modeled and compared. The parameters studied were the material properties (cobalt-chromium, zirconium dioxide, titanium grade 5, and titanium grade 4), diameter and bar-IOD cross-sectional shape, tilt of the posterior implants (30 degrees), presence of a distal extension cantilever in the bar-IODs (12 mm), and number of implants (4 or 6). Two different mastication loading conditions were analyzed. One- and 2-way ANOVAs and the Tukey honestly significant differences post hoc test (α=.05) were used to determine the significant von Mises stress and strain values in the bone.Results
The 4 materials tested in the bar-IOD did not have a significant mechanical effect on the bone (P<.05). A smaller diameter and structure of the bar-IOD led to significantly higher bone stress (P<.001). A distal extension cantilever led to an increased stress concentration (model M1 versus model M3: P<.001), which reached 50% in the event of tilting of the posterior implants (model M2 versus model M4: P<.001). Tilting of the posterior implants alone, without extension, had a nonsignificant effect (model M3 versus model M4: P=.999). Model M5 supported with 6 implants reduces the stress transferred to the bone compared with model M3 supported with 4 implants (P<.05).Conclusions
Distal extensions in bar-IODs, the tilt of the posterior implants, and the low amount of material in the cross-sectional area in the bar-IOD were the most influential parameters on the mechanical resistance of dental implants in the mandibular bone. 相似文献19.
Paulo Valdeci Worm Guilherme Finger Tobias Ludwig do Nascimento Carla Bittencourt Rynkowski Marcus Vinicius Martins Collares 《Journal of cranio-maxillo-facial surgery》2019,47(5):715-719
Objective
To evaluate the quality of life in patients with moderate or large cranial bone defects before and after late cranioplasty.Methods
Authors performed a prospective clinical trial including all consecutive patients that filled inclusion criteria during a period of 1 year. All patients answered the quality of life SF-36 questionnaire in 5 different times. Besides authors gathered information about the primary trauma and demographic characteristics.Results
A total of 70 consecutive patients were admitted to the hospital during the study period, and 62 were included in the project. Cranioplasty statistically improved patients' quality of life in all 8 domains after a 24 months follow-up.Conclusion
Cranioplasty has a significant impact over the quality of life in brain trauma victims who survived the primary trauma and harbor a large cranial bone defect. 相似文献20.
Bruna M. Vetromilla Lucas P. Brondani Tatiana Pereira-Cenci César D. Bergoli 《The Journal of prosthetic dentistry》2019,121(3):398-403.e3