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1.
Thomas F. Putters Gerry M. Raghoebar Jenneke Klein-Nulend Arjan Vissink Jurjen Schortinghuis 《Journal of cranio-maxillo-facial surgery》2019,47(1):23-28
Purpose
The aim of this study was to describe the surgical technique of immediate dental implant placement in calvarial grafts for augmentation of the severely resorbed maxilla and to assess the treatment results.Methods
In 13 patients the maxilla was augmented with calvarial bone followed by simultaneous dental implant placement (total: 68 implants). In the frontal “knife edge” region, implants were inserted in the buccal plated area. In the maxillary sinus area, implants were inserted into alveolar bone that was plated buccally or palatally through the sinus window. After 4 months, the implants were retrieved and subsequently loaded. Per-operative and post-operative variables were scored. One bone biopsy sample was taken for histological analysis.Results
The surgical procedure and wound healing was uneventful. During abutment connection after 4 months, all implants were fully osseointegrated with no signs of graft resorption. Radiographically, the mean (±SD) peri-implant bone loss after 1 year of functional loading was 0.23 ± 0.44 mm. No implants were lost. Histological examination revealed vital calvarial and maxillary bone with active remodeling.Conclusion
Immediate dental implant placement in calvarial bone grafts to rehabilitate severely resorbed maxilla is technically feasible and seems to have a high success rate. 相似文献2.
Paul Weigl Georgia Trimpou Jonas Lorenz Georg-Hubertus Nentwig Hans-Christoph Lauer 《The Journal of prosthetic dentistry》2019,121(4):618-622
Statement of problem
Nonrigid retainer systems for removable implant superstructures are associated with negative effects such as rocking and increased load on the denture base. Rigid retainer systems such as telescopic crowns reduce these negative effects, but their fabrication demands highly skilled dental technicians and is therefore expensive. Whether a protocol with prefabricated retainers will reduce production time is unclear.Purpose
The purpose of this prospective clinical trial was to evaluate a prefabricated telescopic retainer and a treatment protocol including the intraoral luting of a framework.Material and methods
A total of 23 participants (15 women and 8 men with a mean age of 61.6 ±2.9 years) were included. After 3 dropouts, 21 removable dentures (9 mandibular and 12 maxillary) retained by 91 delayed loaded Ankylos implants were investigated. All implants were restored with prefabricated conically shaped abutments (SynCone-abutment). The prefabricated corresponding cone matrix was assembled intraorally into a metal frame with autopolymerizing resin. After a loading period of 3 years, a follow-up examination investigated the fit of the framework, the prosthetic aftercare, the technical failures, and the retention force. A questionnaire was used to evaluate participant satisfaction. In addition, laboratory fabrication time and costs were compared with those of individually fabricated restorations.Results
One mandibular implant was lost after 25 months (survival rate, 98.9%). The removable dentures showed no apparent rocking and minimal prosthetic maintenance during the 36-month trial. No dentures required relining. The retention force was scored as good in 17 participants and high (with 6 implants in the maxilla) and low (with 2 implants in the mandible) in 2 participants each. No technical failures occurred. An assessment of laboratory fabrication time and costs revealed reduced time and costs. Patient satisfaction was significantly increased (P<.001) over the entire observation time.Conclusions
The SynCone retainer presented a time- and cost-efficient treatment option with sufficient long-term retention for removable dentures and high patient satisfaction. Mandibular prostheses restored with 2 implants had limited success. 相似文献3.
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4.
Alexander R. Edelmann Devang Patel Riley K. Allen Chad J. Gibson Al M. Best Sompop Bencharit 《The Journal of prosthetic dentistry》2019,121(3):404-410
Statement of problem
The design of porous tantalum trabecular metal–enhanced titanium (TM) dental implants promises improved osseointegration, especially when grafting materials such as demineralized bone matrix are used; however, studies are lacking.Purpose
The purpose of this retrospective study was to compare TM implants with conventional titanium alloy (Ti) implants with and without demineralized bone matrix in terms of peri-implant bone remodeling in the first year after implant loading.Material and methods
A chart review was used for all patients receiving Tapered Screw-Vent Ti and TM implants. Implants were placed and restored by a single provider between 2011 and 2015. Peri-implant bone remodeling was compared by using a paired t test (α=.05).Results
A total of 82 patients received 205 implants, 44 TM and 161 Ti implants (control). No implants failed in the TM group (survival rate of 100%), and 3 implants in total, 1 immediate, failed in the Ti groups (survival rate of 98.1%). TM implants exhibited a 0.28-mm bone gain on average, whereas the control group demonstrated 0.20 mm of marginal bone loss after the first year of implant loading. Multivariate logistic regression analysis demonstrated that the odds of having bone loss was 64% less (odds ratio: 0.36; 95% confidence interval: 0.14-0.94) in the TM group than in the Ti group after controlling for bone grafting, implant location, immediate placement, bone type, and pretreatment bone level.Conclusions
TM implants exhibited less peri-implant bone loss than the control Ti implants. 相似文献5.
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6.
Sven Mühlemann Goran I. Benic Vincent Fehmer Christoph H.F. Hämmerle Irena Sailer 《The Journal of prosthetic dentistry》2019,121(2):252-257
Statement of problem
Clinical trials are needed to evaluate the digital and conventional fabrication technology for providing fixed partial dentures (FPDs).Purpose
The purpose of the second part of this clinical study was to compare the laboratory production time for tooth-supported, 3-unit FPDs by means of computer-aided design and computer-aided manufacturing (CAD-CAM) systems and a conventional workflow. In addition, the quality of the 3-unit framework of each treatment group was evaluated clinically.Material and methods
For each of 10 participants, a 3-unit FPD was fabricated. Zirconia was used as the framework material in the CAD-CAM systems and included Lava C.O.S. CAD software (3M) and centralized CAM (group L); CARES CAD software (Institut Straumann AG) and centralized CAM (group iT); and CEREC Connect CAD software (Dentsply Sirona) and centralized CAM (group C). The noble metal framework in the conventional workflow (group K) was fabricated by means of the traditional lost-wax technique. All frameworks were evaluated clinically before veneering. The time for the fabrication of the cast, the 3-unit framework, and the veneering process was recorded. In addition, chairside time during the clinical appointment for the evaluation of the framework was recorded. The paired Wilcoxon test together with appropriate Bonferroni correction was applied to detect differences among treatment groups (α=.05).Results
The total effective working time (mean ±standard deviation) for the dental technician was 220 ±29 minutes in group L, 217 ±23 minutes in group iT, 262 ±22 minutes in group C, and 370 ±34 minutes in group K. The dental technician spent significantly more time in the conventional workflow than in the digital workflow, independent of the CAD-CAM systems used (P<.001).Conclusions
Irrespective of the CAD-CAM system, the overall laboratory time for the dental technician was significantly less for a digital workflow than for the conventional workflow. 相似文献7.
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8.
Goran I. Benic Irena Sailer Marco Zeltner Janine N. Gütermann Mutlu Özcan Sven Mühlemann 《The Journal of prosthetic dentistry》2019,121(3):426-431
Statement of problem
Trials comparing the overall performances of digital and conventional workflows in restorative dentistry are lacking.Purpose
The purpose of the third part of this clinical study was to test whether the fit of zirconia 3-unit frameworks for fixed partial dentures fabricated with fully digital workflows differed from that of metal frameworks fabricated with the conventional workflow.Material and methods
In each of 10 participants, 4 fixed-partial-denture frameworks were fabricated for the same abutment teeth according to a randomly generated sequence. Digital workflows were applied for the fabrication of 3 zirconia frameworks with Lava, iTero, and Cerec infiniDent systems. The conventional workflow included a polyether impression, manual waxing, the lost-wax technique, and the casting of a metal framework. The discrepancies between the frameworks and the abutment teeth were registered using the replica technique with polyvinyl siloxane. The dimensions of the marginal discrepancy (Discrepancymarginal) and the internal discrepancy in 4 different regions of interest (Discrepancyshoulder, Discrepancyaxial, Discrepancycusp, and Discrepancyocclusal) were assessed using a light microscope. Post hoc t tests with Bonferroni correction were applied to detect differences (α=.05).Results
Discrepancyshoulder was 96.1 ±61.7 μm for the iTero, 106.9 ±96.0 μm for the Lava, 112.2 ±76.7 μm for the Cerec infiniDent, and 126.5 ±91.0 μm for the conventional workflow. The difference between the iTero and the conventional workflow was statistically significant (P=.029). Discrepancyocclusal was 153.5 ±66.8 μm for the iTero, 203.3 ±127.9 μm for the Lava, 179.7 ±63.1 μm for the Cerec infiniDent, and 148.8 ±66.8 μm for the conventional workflow. Discrepancyocclusal was significantly lower for the conventional workflow than for the Lava and the Cerec infindent workflows (P<.01). The iTero resulted in significantly lower values of Discrepancyocclusal than the Lava and the Cerec infiniDent workflows (P<.01).Conclusions
In terms of framework fit in the region of the shoulder, digitally fabricated zirconia 3-unit frameworks presented similar or better fit than the conventionally fabricated metal frameworks. In the occlusal regions, the conventionally fabricated metal frameworks achieved a more favorable fit than the CAD-CAM zirconia frameworks. 相似文献9.
Sameh Attia Jörg Wiltfang Philipp Streckbein Jan-Falco Wilbrand Thaqif El Khassawna Katharina Mausbach Hans-Peter Howaldt Heidrun Schaaf 《Journal of cranio-maxillo-facial surgery》2019,47(5):786-791
Purpose
Microvascular fibula flap surgery is a reliable and effective procedure for reconstructing the jaws after tumour surgery. This procedure allows the placement of dental implants after bone consolidation. This study was designed to evaluate the oral, functional, and aesthetic rehabilitation of tumour patients with immediate fibula transfer and dental implants and included assessment of diet, speech, and aesthetics.Materials and methods
The study included 34 patients who underwent ablative tumour surgery and immediate jaw reconstruction using a fibula free flap with consecutive rehabilitation by dental implants. In total, 134 implants were inserted into the transferred fibula. The functional and aesthetic results were assessed using a questionnaire. Implant loss and oral excursion were compared with diet type, speech ability, functionality, and patient satisfaction.Results
Of the 34 patients included in this study, 33 completed the questionnaire. Twenty-six patients (76%) could eat normally without the limitation of a hard or soft diet, 73% could speak intelligibly, and 31 rated the aesthetic result from good to excellent.Conclusion
The fibula flap with the early application of endosseous implants allowed primary immediate reconstruction of the jaw, significantly leading to functional and aesthetic satisfaction in patients who underwent ablative tumour surgery. 相似文献10.
Irena Sailer Sven Mühlemann Vincent Fehmer Christoph H.F. Hämmerle Goran I. Benic 《The Journal of prosthetic dentistry》2019,121(1):69-75
Statement of problem
Clinical trials are needed to evaluate digital and conventional technologies for providing fixed partial dentures.Purpose
The purpose of the first part of this clinical study was to test whether complete-arch digital scans were similar to or better than complete-arch conventional impressions regarding time efficiency and participant and clinician perceptions.Material and Methods
Ten participants in need of a posterior tooth-supported 3-unit fixed partial denture were included. Three intraoral digital scanners and subsequent workflows (Lava C.O.S.; 3M [Lava], iTero; Align Technology Inc [iTero], Cerec Bluecam; Dentsply Sirona [Cerec]) were compared with the conventional impression method using polyether (Permadyne; 3M) and the conventional workflow. A computer-generated randomization list was used to determine the sequence of the tested impression procedures for each participant. The time needed for the impression procedures, including the occlusal registration, was assessed. In addition, the participant and clinician perceptions of the comfort and difficulty of the impression were rated by means of visual analog scales. Data were analyzed with the nonparametric paired Wilcoxon test together with an appropriate Bonferroni correction to detect differences among the impression systems (α=.05).Results
The total time for the complete-arch impressions, including the preparation (powdering) and the occlusal registration, was shorter for the conventional impression than for the digital scans (Lava 1091 ±523 seconds, iTero 1313 ±418 seconds, Cerec 1702 ±558 seconds, conventional 658 ±181 seconds). The difference was statistically significant for 2 of the 3 digital scanners (iTero P=.001, Cerec P<.001). The clinicians preferred the conventional impression to the digital scans. Of the scanning systems, the system without the need for powdering was preferred to the systems with powdering. No impression method was clearly preferred over others by the participants.Conclusions
For complete-arch impressions, the conventional impression procedures were objectively less time consuming and subjectively preferred by both clinicians and participants over digital scan procedures. 相似文献11.
Amir Reza Hendi Mohammad Moharrami Hakimeh Siadat Habib Hajmiragha Marzieh Alikhasi 《The Journal of prosthetic dentistry》2019,121(2):364.e1-364.e6
Statement of problem
Conventional cast metal posts and cores are fabricated using direct and indirect techniques, both of which need impression materials and considerable laboratory work. Digital techniques have the capacity to substitute for conventional methods in fabricating the posts and cores. However, the accuracy of restorations resulting from a digital workflow is unknown.Purpose
The purpose of this in vitro study was to compare the retention of posts and cores fabricated using full-digital, half-digital, and conventional techniques and to define the accuracy of each technique in terms of the apical gap.Method and materials
Thirty newly extracted mandibular first and second premolar teeth were selected for this in vitro study. Impressions were made using direct acrylic resin patterns (conventional), indirect silicone impressions of the intracanal which scanned with a 3Shape laboratory scanner (half digital), and intracanal scan posts captured with an intraoral 3Shape scanner (full digital). Casting and milling were conducted for the conventional impression and digital scans. The obtained posts were cemented using zinc phosphate cement. A universal pullout test was used to measure retention at a crosshead speed of 0.5 mm/min. The apical gap of each post in the canals was defined with parallel digital radiography. The data were analyzed using the Kruskal-Wallis test (α=.05) and Mann-Whitney test at the adjusted α=.016.Results
Significant differences were found among the conventional, full-digital, and half-digital techniques in terms of the apical gap (0.11, 0.29, and 0.66 mm; P<.001) and retention (171.6 ±1.9, 107.1 ±5.6 and 91.8 ±6.6 N; P<.001). The correlation between gap and retention in conventional (P=.43), full-digital (P=.09), and half-digital techniques (P=.06) was not statistically significantly different.Conclusions
The conventional technique was more accurate and resulted in higher retention than both the full- and half-digital techniques. However, the retention and gap of all the posts fell within clinical guidelines. 相似文献12.
Statement of problem
Clinicians are aware that the vertical dimension of occlusion and the interocclusal rest space (IRS) are 2 major factors that require consideration in the management of patients needing oral reconstructive procedures. However, how the dimensions vary with age and prosthetic status is unclear.Purpose
The purpose of this clinical study was to analyze the IRS in dentate, partially edentulous, and completely edentulous participants using both conventional and electromyographic (EMG)-based methods. The effect of age and prosthodontic status on the clinical and EMG assessment of the IRS was also explored.Material and methods
The IRS was determined for a group of dentate (n=31) and partially edentate (n=31) participants, as well as a group of completely edentulous (n=31) participants who had worn dentures for at least 10 years before participating in the study. Clinical and EMG-based assessments (monitoring both elevator and depressor activity) were carried out using 5 different methods: rest, relaxing mask, phonetics, deglutition, and myobalance. Bivariate and multivariate analyses (forward stepwise linear regression models) were performed to compare the effect of age and prosthodontic status on the IRS (α=.05).Results
The average IRS values obtained from clinical and EMG-based assessments were significantly greater among dentate participants (2.8 ±0.4 mm and 3.6 ±0.6 mm, respectively) than partially edentulous (1.9 ±0.5 mm and 2.6 ±0.5 mm) and completely edentulous participants (1.4 ±0.5 mm and 2.2 ±0.6 mm). The IRS values obtained using the 5 methods of clinical assessment were statistically smaller than those obtained by EMG. Correlation and regression analyses showed that age and extended edentulism significantly decreased the IRS. For the IRS determined clinically, a decrease was found of 0.01 to 0.02 mm/year, based on the age of the participant. However, this decrease became greater (0.05 to 0.6 mm) where the participant had changed from being dentate to partially edentulous and partially edentulous to completely edentulous.Conclusions
The IRS becomes significantly smaller in relation to age and denture extension. The rest position in the clinical examination was located cranial to the position used to make the EMG-based measurement. Small but significant differences were found between the IRS values obtained in the clinical and EMG-based methods of assessment in all the prosthetic groups. 相似文献13.
14.
Seyed Aliakbar Vahdati Mahmoud Torabinejad Robert Handysides Jamie Lozada 《Journal of endodontics》2019,45(2):99-103
Introduction
Currently, no study has compared the outcome of nonsurgical root canal treatment (NSRCT) and single-tooth implants (STIs) provided to the same patient. The purpose of this study was to determine if the survival outcome of the 2 treatment modalities is different.Methods
The medical/dental records of 3671 patients with at least 1 STI and 1 NSRCT were reviewed. One hundred seventy patients with at least a 5-year follow-up were included. The survival outcome of NSRCT and STI and related factors were evaluated.Results
Both treatments had a 95% survival rate with a mean 7.5-year follow-up. Most preoperative and postoperative factors involved in both procedures had no significant effect on the treatment outcomes. The number of adjunct and additional treatments, the number of appointments, the elapsed time before the final restoration, the number of prescribed medications, and the cost of the treatment were significantly higher for STI in comparison with NSRCT.Conclusions
Both NSRCT and STI are highly successful treatments. Compromised teeth that could otherwise be saved by NSRCTs and deemed restorable should not routinely be treatment planned for STI. 相似文献15.
Mohamed H. Helal Hebatullah D. Hendawy Rowan A. Gaber Nourhan R. Helal Moustafa N. Aboushelib 《The Journal of prosthetic dentistry》2019,121(1):118-123
Statement of problem
Reconstruction of alveolar bony defects is difficult using grafting materials in a powder form. A biodegradable scaffold material might simplify the procedure.Purpose
The purpose of this in vivo study was to evaluate osteogenesis ability of a biodegradable CAD-CAM–fabricated polylactic acid (PLA) scaffold enriched with calcium phosphate salts including hydroxyapatite (HA) and beta tricalcium phosphate (β-TCP) used to reconstruct mandibular defects in a dog model.Material and Methods
Surgical defects were made bilaterally in the mandible of male beagle dogs. Computerized tomography images were obtained for determination of the 3-dimensional shape of the defects after 3 months of healing. Porous PLA scaffolds were fabricated by milling custom-made CAD-CAM blocks into the desired shape. After milling, half of the scaffolds were prepared by filling the pores of the scaffolds by a mixture of HA and β-TCP. Scaffolds were inserted in the mandibular defects bilaterally. After a healing time of 8 weeks, the bone-scaffold interface was analyzed histomorphometrically to detect the amount of new bone formation. Stained histological sections were examined using a computer software and depth of new bone formation was assessed (n=14, α=.05).Results
Histomorphometric analysis revealed that enriched scaffolds with calcium phosphates had significantly (t=4.4, P<.001) higher amounts of new bone formation (1.3 ±0.33 mm) compared with the controls (0.7 ±0.39 mm). Average new bone growth in enriched scaffolds was 1.3 mm while almost half this value was observed in uncoated scaffolds, 0.7 mm.Conclusions
Within the limitations of this animal study, HA and β-TCP enhanced osteogenesis ability of CAD-CAM–fabricated PLA scaffolds. 相似文献16.
Aims
To evaluate the efficiency of reconstruction of long span mandibular defects using split rib bundle bone graft.Materials and methods
Six hundred patients with long span mandibular defects (more than 6 cm long), following resection of aggressive mandibular tumours, were reconstructed with split rib bundle bone graft technique. Immediate reconstruction was performed in all patients. A reconstruction plate was used to support the graft. Two ribs were harvested from the right side of the chest, split into four halves and used to restore the continuity of the mandible. The inclusion criterion was post-surgical mandibular bony defects without soft tissue deficiency. Defects with a history of previous or need of future irradiation were excluded.Results
The appearance of the patients was accepted in 550 patients. Functional reconstruction was done in 320 patients by osseointegrated dental implants (after 15 months), and removable prosthesis in 150 patients. Infection was minor in 31 patients, moderate in 47 patients and severe in 42 patients. Partial loss of graft, up to 25%, due to moderate infection was reported. Total or near total loss of graft due to severe infection was corrected by reoperation six months later.Conclusions
This technique is simple, safe, and can be effectively used to reconstruct long-span mandibular defects with minimal complications in selected patients. 相似文献17.
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18.
Carlo Maiorana Pier Paolo Poli Anna Mascellaro Susanna Ferrario Mario Beretta 《Journal of cranio-maxillo-facial surgery》2019,47(5):805-814
Purpose
To evaluate the long-term outcome of dental implants placed with a staged procedure in resorbed alveolar ridges reconstructed with iliac crest autogenous onlay grafts.Materials and methods
All consecutive patients treated with iliac crest onlay bone grafts and dental implants were retrospectively evaluated. During the appointment, clinical and radiological examinations were conducted to assess implant survival. A survived implant was defined as an implant still stable and in function at the follow-up visit. Implant survival was estimated at the implant level using Kaplan-Meier analyses. The cumulative survival rate was estimated using a life-table analysis. Subgroup analyses were performed for age, position, and type of retention using the log-rank test. A p-value of <0.05 was considered statistically significant.Results
The cohort consisted of 21 female subjects receiving a total of 140 rough-surface titanium implants. Of them, 128 survived and 12 failed, yielding a cumulative survival rate of 91.1% over a median survival time of 312 months. Implants supporting cement-retained prostheses exhibithed lower survival rate compared to screw-retained restorations (p = 0.001).Conclusion
Implants placed in bone augmented with iliac crest onlay grafts showed high long-term survival rates. Cement-retained restorations were more prone to develop implant failures. 相似文献19.
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20.