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1.
Computer-aided implantology using a single fixed stereolithographic surgical guide involves a sequence of diagnostic and therapeutic events, and errors can creep in at different stages. Taken together, these can be termed the ‘total error’. A positioning of the surgical guide on the support surface different to that of the diagnostic template may generate an error that reoccurs with all the implants inserted, and this error can be termed the ‘guide positioning error’. The aim of the present study was to measure the deviation between the planned and inserted implants due to this guide positioning error, to evaluate if this error was statistically significant, and concurrently, to assess the influence of the type of arch (upper vs lower jaw) and mucosal thickness on the guide positioning error. Twenty-four subjects were treated and 172 implants inserted. Preoperative and postoperative computed tomography images were compared using Mimics software to determine the total error and guide positioning error. Quantitative data were described; the t-test and Pearson correlation coefficient were used. The guide positioning error was found to affect the accuracy, but was statistically significant only for global coronal deviation (P = 0.038). Arch of support and mucosa thickness did not affect the guide positioning error.  相似文献   

2.
The aim of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the outcomes of short dental implants (≤7 mm) versus vertical bone augmentation followed by regular dental implants (>7 mm) in the deficient posterior mandible. In total, eight RCTs (six using interpositional sandwich grafting and two using a guided bone regeneration technique) were reported in 17 articles at different time points. In the meta-analysis of the sandwich group, the relative risk (RR) for implant loss at 1 year was in favour of short implants (RR 0.41, P = 0.02), while no significant difference was found at 3 years (RR 0.65, P = 0.43), 5 years (RR 1.08, P = 0.86), or 8 years (RR 1.53, P = 0.52). The risk of complications was in favour of short implants (RR 0.34, P = 0.0002), as was the mean difference in marginal bone resorption after 1 year (−0.09 mm, P = 0.17), 3 years (−0.32 mm, P < 0.00001), 5 years (−0.65 mm, P < 0.00001), and 8 years (−0.88, P < 0.00001). The mean residual osseointegration length of the implants was between 2.94 mm and 4.44 mm in the short implants group and between 7.97 mm and 8.62 mm in the regular implants group after 5 years. In conclusion, in the deficient atrophic posterior mandible, short implants and regular implants demonstrate comparable outcomes within the first 5 years. Patients who are fit for surgery should be informed about the risks and benefits of both options.  相似文献   

3.
Osteoporosis is caused by an imbalance in bone remodelling. The aim of this study was to compare the marginal bone loss (MBL) around dental implants placed in the posterior maxilla between osteoporotic and non-osteoporotic female patients. This was a prospective cohort study. Female patients needing a dental implant restoration in the posterior maxilla were included. Dual-energy X-ray absorptiometry was performed and the T-score recorded. MBL was measured at 12 months after loading. The patients were assigned to one of two groups: group 1, osteoporotic (T-score ≥2.5); group 2, non-osteoporotic (T-score <2.5). In this study, osteoporosis was the primary predictor variable and MBL was the outcome variable. The mean MBL was compared between the two groups using an independent t-test. Pearson’s correlation test was applied to identify any correlation between the T-score and MBL. Ninety female patients were studied, 44 in group 1 and 46 in group 2. The mean MBL was 1.20 ± 0.29 mm in group 1 and 0.87 ± 0.15 in group 2; this difference in mean MBL was statistically significant (P = 0.001). There was a correlation between T-score and MBL (P = 0.001). Despite the correlation between T-score and MBL, this study did not provide enough evidence to prove any causal relationship between MBL and osteoporosis.  相似文献   

4.
Immediate implant placement holds considerable value, yet primary implant stability is often a critical factor. The aim of this study was to evaluate the stability, volumetric viability, and buccal gap size of reverse tapered body shift (RTBS) implants after immediate placement. Peak insertion torque measurements of two RTBS designs (apical 40% vs. apical 50%), relative to conventionally tapered implants, were assessed in simulated extraction sockets prepared in synthetic bone blocks. Additionally, the proximity of the RTBS implants to neighbouring teeth and anatomical structures, and the buccal gap distance were evaluated in human cadavers. The mean (± standard deviation) insertion torque was 12.00 ± 1.40 N•cm for the conventionally tapered implants (n = 50), 35.36 ± 2.74 N•cm (n = 50) for RTBS-1, and 48.20 ± 2.90 N•cm (n = 50) for RTBS-2; the difference between designs was statistically significant (P < 0.01). In total, 40 RTBS implants (20 per design) were placed in six cadaveric premaxillae. Only one locus was inappropriate for both RTBS implant designs, due to the proximity of neighbouring teeth. The average buccal gap for both implant designs was 2.8 mm (P = 0.104). The improved primary stability and increased buccal gap size with RTBS implants may enhance the feasibility of immediate placement. The study findings should be further validated in clinical trials.  相似文献   

5.
The objectives of this study were to verify whether Chinese patients are well-suited for zygomatic implantation and to observe age-related changes in the linear and angular anatomic bases of the maxilla and zygoma. Using three-dimensional images selected from maxillofacial cone beam computed tomography (CBCT) scans generated by SimPlant, linear and angular measurements were obtained by simulating zygomatic implantation. The edentulous group comprised 40 subjects aged between 62 and 65 years. A total of 120 dentate cases were divided into three groups based on age: the established occlusion group (n = 40; 12–15 years old), the adult group (n = 40; 37–40 years old), and the elderly group (n = 40; 62–65 years old). The mean potential insertion length of the ordinary and additional zygomatic implants became longer with age in the dentate groups. For both zygomatic implant insertion areas, the anteroposterior lengths of the maxilla and zygoma were thicker in the older dentate groups (P < 0.05). Significant differences were verified in the installation direction among the dentate groups. Gender was not a significant factor. The zygomatic skeleton changes with age, which results in linear and angular variations in the zygomatic implant insertion area. Therefore, the anatomic bases in Chinese adults are suitable for zygomatic implants.  相似文献   

6.
Information concerning the effects of the implant cutting flute design on initial stability and its influence on osseointegration in vivo is limited. This study evaluated the early effects of implants with a specific cutting flute design placed in the sheep mandible. Forty-eight dental implants with two different macro-geometries (24 with a specific cutting flute design – Blossom group; 24 with a self-tapping design – DT group) were inserted into the mandibular bodies of six sheep; the maximum insertion torque was recorded. Samples were retrieved and processed for histomorphometric analysis after 3 and 6 weeks. The mean insertion torque was lower for Blossom implants (P < 0.001). No differences in histomorphometric results were observed between the groups. At 3 weeks, P = 0.58 for bone-to-implant contact (BIC) and P = 0.52 for bone area fraction occupied (BAFO); at 6 weeks, P = 0.55 for BIC and P = 0.45 for BAFO. While no histomorphometric differences were observed, ground sections showed different healing patterns between the implants, with better peri-implant bone organization around those with the specific cutting flute design (Blossom group). Implants with the modified cutting flute design had a significantly reduced insertion torque compared to the DT implants with a traditional cutting thread, and resulted in a different healing pattern.  相似文献   

7.
This retrospective study was performed to evaluate nasomaxillary changes in 36 patients at an advanced stage of skeletal maturity who underwent miniscrew-assisted rapid palatal expansion (MARPE) or surgically assisted rapid palatal expansion (SARPE) with/without an alar base cinch. Cone beam computed tomography images taken before and after expansion were analysed. Changes in the width of the dental arch (D66S, D66I), maxillary base (MxMol), and nasal floor and nasal cavity in the molar and canine regions (NaFMol, NaFCan, NaCMol, NaCCan) were compared, as well as changes in the choanal aperture (CA) and nasal soft tissue (NW). The MARPE technique produced smaller dental changes (D66S; P = 0.025) and greater nasomaxillary expansion (MxMol, P = 0.010; NaCMol, P = 0.016; NaCCan, P = 0.017; NaFMol, P = 0.001; CA, P = 0.002) than both SARPE techniques. Changes in NW did not differ significantly between the groups (P = 0.200). MARPE uniformly increased the anterior and posterior widths of the nasal cavity. SARPE expanded the nasal cavity in a ‘V-shape’ pattern. Changes in the nasal cavity and choanal aperture related to the amount of dental arch expansion were greater for MARPE than for SARPE. All three approaches increased the width of the nasal soft tissue, although the cinch in SARPE limited this increase.  相似文献   

8.
Data from cone beam computed tomography (CBCT) and optical scans (intraoral or model scanner) are required for computer-assisted implant surgery (CAIS). This study compared the accuracy of implant position when placed with CAIS guides produced by intraoral and extraoral (model) scanning. Forty-seven patients received 60 single implants by means of CAIS. Each implant was randomly assigned to either the intraoral group (n = 30) (Trios Scanner, 3Shape) or extraoral group (n = 30), in which stereolithographic surgical guides were manufactured after conventional impression and extraoral scanning of the stone model (D900L Lab Scanner, 3Shape). CBCT and surface scan data were imported into coDiagnostiX software for virtual implant position planning and surgical guide design. Postoperative CBCT scans were obtained. Software was used to compare the deviation between the planned and final positions. Average deviation for the intraoral vs. model scan groups was 2.42° ± 1.47° vs. 3.23° ± 2.09° for implant angle, 0.87 ± 0.49 mm vs. 1.01 ± 0.56 mm for implant platform, and 1.10 ± 0.53 mm vs. 1.38 ± 0.68 mm for implant apex; there was no statistically significant difference between the groups (P > 0.05). CAIS conducted with stereolithographic guides manufactured by means of intraoral or extraoral scans appears to result in equal accuracy of implant positioning.  相似文献   

9.
The aim of this systematic review and meta-analysis was to evaluate studies comparing implant survival rates, marginal bone loss (MBL), and mechanical and biological complication rates between narrow-diameter implants (NDIs) and regular-diameter implants (RDIs) used for oral rehabilitation in the anterior region. The review was conducted according to the PRISMA checklist. Two independent reviewers performed a comprehensive search of the PubMed/MEDLINE, Embase, Scopus, and Cochrane Library databases for studies published until May 2020. A total of 843 implants (484 NDIs and 359 RDIs) were included. No significant difference in implant survival rate (risk difference (RD) 0.01, 95% confidence interval (CI) ?0.01 to 0.03; P = 0.34), MBL (standardised mean difference ?0.51 mm, 95% CI ?1.29 to 0.26 mm; P = 0.19), mechanical complications (RD 0.01, 95% CI ?0.02 to 0.04; P = 0.40), or biological complications (RD 0.01, 95% CI ?0.09 to 0.11; P = 0.85) was found between the implant groups. Within the limitations of this study, it is concluded that NDIs are an effective alternative to RDIs due to similar survival rates, MBL, and mechanical and biological complication rates. However, future studies are highly encouraged due to the small number of interventional studies on this topic.  相似文献   

10.
Autogenous bone graft represents the gold standard for mandibular reconstruction. The authors used a beagle mandibular defect model and reconstructed with iliac crest and ulna graft. Healing masseter entheses were harvested 24 weeks after surgery and analyzed by histology and Raman microspectroscopy. The intensity ratio of 960/2940 was to document mineral-to-collagen ratio as degree of mineralization. Pearson correlation was used to evaluate the association between the intensity ratios of 960/2940 and the tendon-to-bone insertion site. In the normal control group (n = 4) and the experimental control group with detached masseter muscle (n = 4), the degree of mineralization at the insertion site increased linearly from tendon to bone. In the iliac graft (n = 4) and ulna graft groups (n = 4), healing entheses were far less mature than controls and a linear trend was not observed. There was no significant correlation between degree of mineralization and insertion site in the ulna group (rspearman = 0.519, P > 0.001). These results indicate that transplanted bone plays a critical role in healing of entheses and healing enthesis to reconstructed mandible is inferior to normal. Raman spectroscopy provides quantitative information about different healing entheses and gives valuable insight into mechanical properties of entheses in functional mandibular reconstruction.  相似文献   

11.
This study investigated the effect of resveratrol on bone healing and its influence on the gene expression of osteogenic markers. Two calvarial defects were created and one screw-shaped titanium implant was inserted in the tibia of rats that were assigned to daily administration of placebo (control group, n = 15) or 10 mg/kg of resveratrol (RESV group, n = 15) for 30 days. The animals were then sacrificed. One of the calvarial defects was processed for histomorphometric analysis and the tissue relative to the other was collected for mRNA quantification of bone morphogenetic protein (BMP)-2, BMP-7, osteopontin (OPN), bone sialoprotein (BSP), osteoprotegrin (OPG), and receptor activator of NF-κB ligand (RANKL). Implants were removed by applying a counter-torque force. Histomorphometric analysis revealed higher remaining defect in the calvarial defects of the control group than the RESV group (P = 0.026). Resveratrol increased the counter-torque values of implant removal when compared to control therapy (P = 0.031). Gene expression analysis showed a higher expression of BMP-2 (P = 0.011), BMP-7 (P = 0.049), and OPN (P = 0.002) genes in the RESV group than in the control group. In conclusion, resveratrol improved the repair of critical-sized bone defects and the biomechanical retention of implants. Indeed, this natural agent may up-regulate the gene expression of important osteogenic markers.  相似文献   

12.
The aim of this study was to characterize the alveolar bone of edentulous maxillary sites using texture analysis (TA) of cone beam computed tomography (CBCT) images and to correlate the results to the insertion torque, thus verifying whether TA is a predictive tool of final implant treatment. This study was conducted on patients who had received single implants in the maxilla (46 implants) 1 year earlier and whose torque values were properly recorded. Three cross-sections of the sites were selected on CBCT scans. Two regions of interest (ROIs) corresponding to the implant bone site and peri-implant bone were also outlined, according to virtual planning. The CBCT scans were exported to MaZda software, where the two ROIs were delimited following the previously demarcated contours. Values for the co-occurrence matrix were calculated for TA. With regard to the insertion torque value, there was a direct correlation with the contrast of the peri-implant bone (P < 0.001) and an inverse correlation with the entropy of the implant bone site (P = 0.006). A greater contrast indicates a greater torque value for insertion of the implants, and there is a possible association with a lower entropy value of the implant–bone interface.  相似文献   

13.
Zygomatic implant treatment is widely applied for severe maxillary atrophy to help rehabilitate the maxillary dentition. This retrospective study was performed to evaluate the actual radiographic bone–implant contact (rBIC) lengths of zygomatic implants. The records of 28 patients who underwent zygomatic implant surgery and subsequent follow-up examinations between August 2013 and September 2018 in the Department of Oral and Maxillofacial Surgery, Taipei Tzu Chi Hospital were reviewed. The surgeries were performed by a single surgeon using the same treatment protocol. All patients had a computed tomography scan at 1 year after the surgery. Using three-dimensional imaging software, an investigator measured the rBIC lengths of 66 implants and documented their clinical status. The implant survival rate was 100%. The mean rBIC length was significantly longer in male patients than in female patients (20.80 ± 5.88 mm versus 17.79 ± 6.34 mm; P = 0.028). The mean rBIC length of double zygomatic implants was significantly longer when compared to that of single implants (21.11 ± 6.23 mm versus 17.75 ± 5.85 mm; P = 0.027). This article is novel in reporting the exact rBIC lengths of zygomatic implants in a clinical setting. The results showed that zygomatic implants are a viable treatment modality for full-mouth rehabilitation.  相似文献   

14.
The surgical management of head and neck pathologies involving the maxilla and mandible results in significant functional and aesthetic deficits, and ultimately reduced quality of life. Composite free flaps used for reconstruction address many of these deficits and create a foundation for the use of osseointegrated implants to support prosthetic replacement of the dentition. There are few comparative studies examining outcomes of implants in native and reconstructed bone in head and neck cancer patients. The aim of this retrospective cohort study was to compare survival rates and the effects of risk factors between implants placed in native and reconstructed bone. The Kaplan–Meier method estimated cumulative 1- and 5-year implant survival rates of 99.5% and 95% for native bone and 96% and 88% for reconstructed bone. Multivariate Cox regression found an increased risk of implant failure in reconstructed bone (hazard ratio (HR) 9.9, 95% confidence interval (CI) 3.4–29.7, P < 0.001). Subgroup analysis of the cohorts found an increased risk of failure in the reconstructed group associated with radiotherapy (HR 6.4, 95% CI 1.8–22.3, P = 0.004), current smoking (HR 23.2, 95% CI 2.7–198.6, P = 0.004), and previous smoking (HR 9.0, 95% CI 1.1–71.9, P = 0.038). There was no effect in the native bone group. Implants placed into reconstructed bone had higher rates of failure, and smoking status and radiotherapy increased the risk of implant failure.  相似文献   

15.
PurposeTo evaluate the influence of implant scanbody (ISB) material, position and operator on the accuracy of a confocal microscopy intraoral scanning (IOS) for complete-arch implant impression.MethodsAn edentulous maxillary model with 6 internal hexagonal connection analogues was scanned with an extraoral optical scanner to achieve a reference file. Three ISBs made of different materials (polyetheretherketone (Pk), titanium (T) and Pk with a titanium base (Pkt)) were scanned with IOS by 3 operators. The resulting 45 test files were aligned to the reference file with a best fit algorithm. Linear (ΔX, ΔY and ΔZ-axis) and angular deviations (ΔANGLE) were assessed. Absolute values of the linear discrepancies were summed up to obtain a global measure of linear absolute error (ΔASS). Influence of ISB material, position and operator was statistically assessed using the mixed general linear model.ResultsAt multivariate analysis, whenΔASS was considered as response variable, it was identified a significant influence of material (p < 0.0001) and position (p = 0.0009) while no significant operator effect was detected.When ΔANGLE was considered as response variable, material and position significantly influenced the expected ΔANGLE (p = 0.0232 and p < 0.0001) and no operator effect was identified.ConclusionsThe investigated IOS for complete-arch digital impression was influenced by the ISB material with peek reporting the best results on both linear and angular measurements followed by titanium, peek-titanium resulting as the less accurate. Implant angulation affected significantly the linear deviations while implant position the angular deviations. Operator did not show any significant effect on the IOS accuracy.  相似文献   

16.
This investigation was conducted to analyse the usefulness of intraligamentary anaesthesia (ILA) as an alternative anaesthetic procedure in oral implantology. Forty consecutive patients with single-tooth gaps in the posterior mandible were included in the analysis. Implant insertion was performed after ILA of the gap-delimiting teeth (two injections distal to the mesial tooth, two injections mesial to the distal tooth). Implant surgery was performed successfully under ILA of the gap-delimiting teeth in 39 cases. Injection pain correlated significantly with lower periodontal probing depths (<3 mm) of the delimiting teeth (P = 0.003). The total amount of anaesthetic solution and the pain during surgery were significantly higher if a root canal-treated tooth was present in the area of surgery (P = 0.010 and P = 0.020, respectively). Overall, the mean pain score during treatment was low at 0.76 ± 0.51 on a numerical rating scale from 0 to 10. At the control visit, no major complication was encountered. All implants were successfully restored with single crowns after a healing period of 2 months. Taking into consideration the limitations of the study, ILA seems to fulfil all conditions to be defined as an alternative, minimally invasive anaesthetic technique for the insertion of single-gap implants.  相似文献   

17.
The aim of this study was to determine the prevalence of burnout syndrome among Brazilian oral and maxillofacial surgeons and its relationship with socio-demographic, clinical, and habit variables. The sample of this study comprised 116 surgeons. The syndrome was quantified using the Maslach Burnout Inventory (General Survey), which defines burnout as the triad of high emotional exhaustion, high depersonalization, and low personal accomplishment. The criteria of Grunfeld et al. were used to evaluate the presence of the syndrome (17.2%). No significant differences between the surgeons diagnosed with and without the syndrome were observed according to age (P = 0.804), sex (P = 0.197), marital status (P = 0.238), number of children (P = 0.336), years of professional experience (P = 0.102), patients attended per day (P = 0.735), hours worked per week (P = 0.350), use of alcohol (P = 0.148), sports practice (P = 0.243), hobbies (P = 0.161), or vacation period per year (P = 0.215). Significant differences occurred in the variables sex in the emotional exhaustion subscale (P = 0.002) and use or not of alcohol in the personal accomplishment subscale (P = 0.035). Burnout syndrome among Brazilian surgeons is average, showing a low personal accomplishment.  相似文献   

18.
This study used three-dimensional computed tomography and polysomnography to evaluate the effect of a large mandibular setback on the postoperative pharyngeal airway space and obstructive sleep apnoea (OSA). Twelve patients who underwent bimaxillary surgery for a mandibular setback movement of >9 mm were included in this study. Changes in the pharyngeal airway space and polysomnography parameters based on the surgical movements were analyzed. The median mandibular setback movement was 11.08 mm. The total pharyngeal, oropharyngeal, and hypopharyngeal volumes, and the retroglossal cross-sectional area were significantly decreased postoperatively (P = 0.006; P = 0.005; P = 0.012; P = 0.005, respectively). The apnoea–hypopnoea index (AHI) increased significantly after surgery (P = 0.021). There were significant positive correlations between the preoperative inferiorly located hyoid bone and both AHI and respiratory disturbance index (RDI) postoperative (P = 0.008 and P = 0.027) and between the postoperative inferiorly dislocated retropalatal level and both AHI and RDI postoperative (P = 0.002 and P = 0.014). Four patients (33.3%) developed new onset OSA postoperatively. Large mandibular setback movements significantly reduced the pharyngeal airway space in the setting of bimaxillary surgery (P = 0.006).  相似文献   

19.
Calcium phosphate has high osteotransductive potential. The injectable form of calcium phosphate cement (ICAP) can be used as an adjunctive supportive agent for dental implants. The aim of this study was to assess the effect of an ICAP on the reverse torque resistance of titanium implants. Two implant beds (total 24) were prepared in each proximal tibia of 6 beagles. ICAP was injected into one of prepared implant beds (test) and the implant was inserted. The next implant was inserted without ICAP to serve as control. Three dogs were killed after 2 weeks and 3 after 12 weeks. Retrieved implants were subjected to reverse torque test. Results were analyzed with Student's t-test. Scanning electron microscope (SEM) was used for further evaluation. Mean torque values in 2-week healed implants were 52.48 N cm and 50.57 N cm for test and control implants, respectively (p = 0.4). 12-week healed implants showed 81.61 N cm and 76.71 N cm for test and control implants, respectively (p = 0.14). Results indicated no statistical difference between test and control implants for either healing time. SEM images of tested samples revealed close contact between the bone–ICAP–titanium surface. ICAP must be tested on further developed experimental models.  相似文献   

20.
ObjectivesEvidences suggest that hemodialysis patients have reduced salivary flow and changes in the composition of salivary secretion. These changes may reflect local and systemic disorders. The objectives of this study were to compare the salivary levels of calcium (Ca), phosphorus (P), potassium (K) and albumin in hemodialysis patients and healthy subjects, and to investigate a possible correlation between their serum and salivary levels.DesignA case–control study was conducted with 60 hemodialysis patients (HD group) and 37 systemically healthy individuals (control group). Stimulated saliva samples were collected for biochemical analysis (Ca, P, K and albumin). Serum data were collected in the HD group. Statistical analysis included t-test, Pearson correlation and simple linear regression.ResultsThe HD group exhibited higher salivary levels of Ca, P, and albumin (p < 0.05). There was a significant positive correlation between serum PTH and salivary phosphorus (r = 0.342, p = 0.009), and between serum PTH and salivary potassium (r = 0.306, p = 0.020). An increase of 100 pg/dL in serum PTH was associated with an elevation of salivary P levels (0.34 mg/dL, p = 0.009), and salivary K levels (0.20 mmol/dL, p = 0.02), in the HD group.ConclusionsThe findings suggest that HD patients present increased levels of salivary components (Ca, P, and albumin), and changes commonly observed in HD patients, such as hyperparathyroidism, appear to have an influence on salivary composition.  相似文献   

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