Onlay bone grafts from iliac crest: a retrospective analysis

This study was performed to address the outcomes of patients treated with onlay grafts from the iliac crest to augment the deficient jaw. The results of 173 consecutive patients who underwent bone grafting prior to implant surgery are presented. The grafts were taken from the anterior iliac crest to repair alveolar bone deficiencies that were too large to be corrected using intraoral bone grafts. Three months postoperatively, 869 implants were placed into 190 onlay grafts (167 grafts in the maxilla, 23 in the mandible). The follow-up ranged from 3 months to 23 years post implantation. All patients received a fixed prosthesis. Parameters examined included healing of the donor site and bone grafts, implant survival, peri-implant condition, and donor site morbidity. The overall survival rate for all implants was calculated to be 95% ± 2.7% according to Kaplan–Meier analysis. The implant survival rate compares favourably with those reported in studies using intraoral and extraoral bone.     

Initial bone preparation followed by a 2-week delay before implant placement enhances the clinical and radiographic outcome: a randomized controlled trial

Initial bone preparation followed by a 2-week delay before implant placement enhances the biological activity at the osteotomy site, which may improve the treatment outcome. The aim of this study was to compare the clinical and radiographic outcomes of initial bone preparation and a 2-week delay in implant placement with the conventional method. Subjects were outpatients selected from a department of periodontology and oral implantology. The implant sites were randomly allocated to a test group and a control group (n = 7 each). Test sites were treated with initial bone preparation followed by implant placement after a 2-week delay; control sites were treated with the conventional protocol. All sites were assessed over 12 months for the keratinized mucosa index, probing depth, implant mobility, and radiographic peri-implant crestal bone levels. A total of 14 implants were placed in 12 subjects (five males and seven females, mean age 31.5 years, range 18–45 years). The results showed a statistically significant reduction in peri-implant probing depth and crestal bone levels in the test group (P < 0.01). This randomized controlled trial demonstrated better clinical and radiographic outcomes for initial bone preparation followed by a 2-week delay in implant placement; this may be an alternative to the conventional protocol.     

The impact of different torques for the insertion of immediately loaded implants on the peri-implant levels of angiogenesis- and bone-related markers

The aim of this split-mouth, randomized, double-blind, controlled clinical trial was to evaluate the influence of different insertion torque values for dental implants on bone- and angiogenesis-related marker profiles. Eighteen edentulous patients received dental implants and fixed complete-arch mandibular prostheses. The implants (n = 36) were assigned randomly to two groups: reduced torque (n = 18), with insertion torque <30 N cm; and conventional torque (n = 18), with insertion torque ≥30 N cm. Levels of vascular endothelial growth factor (VEGF), placental growth factor, bone morphogenetic protein 9 (BMP-9), periostin, osteoprotegerin (OPG), and tartrate-resistant acid phosphatase (TRAP) in the peri-implant fluid were quantified at 7, 14, 30, and 120 days after implant placement. Inter-group comparisons showed that VEGF and OPG levels were higher in the low-level torque group than in the conventional torque group on days 7 and 30, respectively (P < 0.05). BMP-9 and periostin levels were higher in the conventional group than in the low-level torque group on day 120, and TRAP was up-regulated around implants inserted with conventional torque when compared to those inserted with lower-level torque at all time points evaluated (P < 0.05). In conclusion, the use of different levels of torque for implantation of immediately loaded implants significantly influenced the levels of bone- and angiogenesis-related markers during early peri-implant repair.     

Does platelet-rich fibrin have a role in osseointegration of immediate implants? A randomized,single-blind,controlled clinical trial

Immediate implants are a valuable treatment option to replace natural teeth in the aesthetic region. The hypothesis of this randomized controlled clinical trial was that immediate implants grafted with autologous platelet-rich fibrin (PRF) have better clinical and radiographic outcomes than non-grafted controls. Forty-one implants were placed in 31 subjects with one or more non-restorable single-rooted teeth. Autologous PRF was placed in the peri-implant region of the study group (n = 21) and no augmentation was done in the control group (n = 20). A staged protocol was followed for implant restoration. The patients received a definitive restoration after 3 months and were followed up for a period of 1 year. The statistical analysis included 39 implants sites in 29 subjects. A significant increase in implant stability was noted in both groups over the 3-month period (implant stability quotient: study group 56.58 ± 18.81 to 71.32 ± 7.82; control group 60.61 ± 11.49 to 70.06 ± 8.96; P = 0.01). No significant difference was observed between the groups in terms of implant stability. The hypothesis was thus rejected, as there was no significant effect of PRF on immediate implants with adequate primary stability.     

Rationale for a reverse tapered body shift implant for immediate placement

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.     

Morbidity of anterior iliac crest and calvarial bone donor graft sites: a 1-year randomized controlled trial

Autogenous bone graft harvesting is still commonly considered the gold standard for the reconstruction of a severely resorbed maxillary alveolar ridge; however, the preferred donor site remains a subject of debate. This study compared the morbidity of calvarial and iliac crest donor sites after harvesting. Twenty edentulous patients with an insufficient volume of maxillary bone for reliable implant placement were assigned randomly to either calvarial (n = 10) or anterior iliac crest (n = 10) bone harvesting groups. All patients underwent a maxillary sinus floor elevation procedure combined with widening of the alveolar process using buccal bone blocks. Donor site morbidity was assessed before, during, and at 1 year after the surgery through patient questionnaires, physical examination, and medical records. No perioperative complications occurred. The anterior iliac crest group reported minor postoperative pain after harvesting. The scars after calvaria harvesting were significantly longer (P = 0.003), but this was not bothersome for the group of patients. Long-term pain was negligible and satisfaction was high in both groups. Both the calvaria and anterior iliac crest are associated with low long-term donor site morbidity and high patient satisfaction. Thus, patient-centred decision-making is appropriate when selecting the preferred harvesting method for that patient.     

Clinical evaluation of submerged and non-submerged implants for posterior single-tooth replacements: a randomized split-mouth clinical trial

The aim of this study was to evaluate clinical and radiographic results of submerged and non-submerged implants for posterior single-tooth replacements and to assess patient-based outcomes. Twenty patients were included in the study. A split-mouth design was used; implants inserted using a submerged technique were compared to those inserted with a non-submerged technique. Implants were restored with metal–ceramic crowns after 3 months. Reconstructions were examined at baseline, 6, 12, and 24 months. Standardized radiographs were made. Radiographic crestal bone level changes were calculated, as well as soft tissue parameters, including pocket probing depth, bleeding on probing, plaque index, and gingival index. Results were analyzed by two-way repeated measures of variance (ANOVA). To evaluate patient-based outcomes, patients were asked to complete a questionnaire at the 6-month follow-up; the Wilcoxon paired signed rank test was used to compare scores. The data of 18 patients were reviewed. During 24 months, non-submerged implants (0.57 ± 0.21 mm) showed significantly lower bone loss than submerged implants (0.68 ± 0.22 mm) (P < 0.01). Patient satisfaction with non-submerged implants (median 87.5) was significantly higher than with submerged implants (median 81.5) (P < 0.01). Non-submerged implants showed comparable clinical results to submerged implants and resulted in higher patient satisfaction due to decreased surgical intervention.     

Accuracy of implant position when placed using static computer-assisted implant surgical guides manufactured with two different optical scanning techniques: a randomized clinical trial

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.     

Dental implant placement in alveolar cleft patients: a retrospective comparative study on clinical and aesthetic outcomes

The aim of this retrospective study was to assess the clinical and aesthetic outcomes, and patient satisfaction, following dental implant therapy in cleft patients. Implant survival, changes in marginal bone level, pocket probing depths, plaque and bleeding indices, aesthetics, and patient satisfaction were assessed in 17 alveolar cleft patients and 17 matched controls. At follow-up (mean 72.4 ± 46.4 months), one implant had been lost in the cleft group. Mean marginal bone loss at follow-up was −0.4 ± 0.4 mm in cleft patients and −0.2 ± 0.4 mm in controls. Aesthetics of the peri-implant soft tissues (pink aesthetic score) were less favourable (P = 0.025) in cleft patients (5.0 ± 1.9) than in controls (6.5 ± 1.7), while peri-implant parameters were comparable in the two groups. Overall patient satisfaction was 8.6 ± 0.9 in cleft patients and 8.9 ± 1.1 in controls (P = 0.331). In cleft patients, no difference in aesthetics was observed between patients who received additional bone augmentation at 3 months prior to implant placement and those who did not (P = 0.092). Dental implant therapy in cleft patients is associated with high implant survival, minor marginal bone loss, healthy peri-implant soft tissues, and high patient satisfaction. Only the aesthetics of the soft tissues was worse in cleft patients compared to augmented non-cleft patients.     

Non invasive and surgical measurement of length of soft tissue from the tip of interdental papilla to the alveolar crest

BackgroundVarious methods, including clinical and radiographic techniques, can be used to assess periodontal regeneration in interproximal areas. The goal of the present study was to compare the papilla length relative to the alveolar bone crest measured by clinical, intrasurgical, and radiographic techniques.Materials and methodsThe study sample included 250 interproximal papillae in 68 patients with generalized chronic periodontitis. The papilla length from the alveolar bone crest was measured clinically (as the actual papilla length, APL), intrasurgically (as the bone probing length, BPL), and radiographically (as the radiographic bone length, RBL). Measurements were standardized by using acrylic resin stents, XCP rinn, a paralleling technique, and/or a radiographic grid.ResultsThe mean (± standard deviation) for RBL was 4.9 ± 0.8 mm, BPL was 5.1 ± 0.6 mm, and APL was 5.1 ± 0.6 mm. Correlations between RBL and APL and between BPL and APL were 0.918 and 0.943, respectively (both P < 0.01).ConclusionsIf the clinical recordings are appropriately standardized, then noninvasive radiographic methods can be used to evaluate the papilla length with good accuracy.     

Does platelet-rich fibrin increase the stability of implants in the posterior of the maxilla? A split-mouth randomized clinical trial

The effect of platelet-rich fibrin (PRF) on bone healing around dental implants in areas of poor bone quality has not been studied. The aim of this study was to evaluate the stability of implants placed in the posterior maxilla, with or without the use of PRF, during the healing period. A split-mouth randomized clinical trial was performed. Twenty patients with missing teeth in the molar region of the maxilla, requiring bilateral implants, were included. PRF was used on one side (group 1); no PRF was used on the other (group 2). Implant stability was assessed by resonance frequency analysis (RFA) at 2, 4, and 6 weeks after placement. At 2 weeks, the mean ISQ was 60.60 ± 3.42 in group 1 and 58.25 ± 3.64 in group 2; at 4 weeks it was 70.30 ± 3.36 in group 1 and 67.15 ± 4.33 in group 2; at 6 weeks it was 78.45 ± 3.36 in group 1 and 76.15 ± 2.94 in group 2. Significant differences in RFA were found between the groups at 2 weeks (P = 0.04), 4 weeks (P = 0.014), and 6 weeks (P = 0.027) after placement. The study results suggest that the use of PRF may enhance the post-insertion stability of dental implants placed in the posterior maxilla during the healing period.     

Vertical bone augmentation and regular implants versus short implants in the vertically deficient posterior mandible: a systematic review and meta-analysis of randomized studies

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.     

Intraligamentary anaesthesia as a possible anaesthetic option in oral implantology: a retrospective analysis

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.     

Frequency of periodontal pathogens in equivalent peri-implant and periodontal clinical statuses

ObjectivesThis study tested the hypotheses that there is: (1) higher bacterial frequency in peri-implantitis/periodontitis, followed by mucositis/gingivitis and peri-implant/periodontal health; (2) similar bacterial frequency between comparable peri-implant and periodontal clinical statuses.Design of studyThe presence of Porphyromonas gingivalis, Tannerella forsythia, Campylobacter rectus, Prevotella intermedia, Treponema denticola and Aggregatibacter actinomycetemcomitans was evaluated in peri-implant (n = 53) and periodontal (n = 53) health; mucositis (n = 50), gingivitis (n = 50), peri-implantitis (n = 50) and periodontitis (n = 50).ResultsThe pattern of peri-implant bacterial frequency was not as expected (peri-implantitis > mucositis > health). Except for P. intermedia (p > 0.05), bacterial frequency was higher in peri-implantitis than health (p < 0.05). The frequency of P.gingivalis and red complex species were higher in peri-implantitis than mucositis (p < 0.05). In periodontal samples, T. forsythia and T. denticola showed the expected pattern of frequency (periodontitis > gingivitis > health). The frequencies of C. rectus and T. forsythia were higher in healthy teeth/gingivitis than healthy implants/mucositis, respectively (p < 0.05). The frequency of P. gingivalis and A. actinomycetemcomitans were similar between periodontitis and peri-implantitis (p > 0.05) while all other species occurrences were higher in periodontitis than peri-implantitis (p < 0.05).ConclusionsBacterial frequency increased from peri-implant/periodontal health to peri-implantitis/periodontitis but not from mucositis/gingivitis to peri-implantitis/periodontitis. There was a trend towards higher bacterial frequency in teeth than implants.     

Molecular alterations of newly formed mandibular bone caused by zoledronate

Bone quality is defined by structural and material characteristics. Most studies on the mandible have focused on the analysis of structural characteristics, with insufficient investigation of material characteristics. This study tested whether zoledronate affects the material characteristics of newly formed mandibular bone. Thirty-six female Wistar rats were assigned to three groups: sham-ovariectomized rats (SHAM, n = 12), ovariectomized rats (OVX, n = 12), and ovariectomized rats treated with zoledronate (ZOL, n = 12). The left side of the mandibular ramus of all rats was drilled bicortically. Twenty-eight days after surgery, all surviving rats were euthanized and all mandibles were removed. Raman microspectroscopy was performed, and five spectra per specimen of newly formed mandibular bone were analysed. Compared with OVX rats, the mineral/matrix ratio in ZOL rats was significantly increased (5.43 ± 1.88 vs. 7.86 ± 2.05), while crystallinity (0.055 ± 0.002 vs. 0.050 ± 0.002), relative proteoglycan content (0.43 ± 0.10 vs. 0.31 ± 0.05), and collagen structural integrity (1.16 ± 0.21 vs. 0.72 ± 0.06) were significantly decreased. These changes in material characteristics may explain why rats that received zoledronate exhibited peculiar biological phenomena such as bisphosphonate-related osteonecrosis of the jaw.     

Early implant placement and peri-implant augmentation with a porcine-derived acellular dermal matrix and synthetic bone in the aesthetic area: a 2-year follow-up prospective cohort study

The aim of this study was to evaluate the 2-year follow-up results of early implant placement with simultaneous peri-implant augmentation using an acellular dermal matrix (ADM) and a synthetic bone substitute in the aesthetic zone. Twenty subjects were enrolled in this study, they were either males (eight) or females (12), with a mean age of 47.8 ± 4.45 years and each patient was treated with one implant. Simultaneous contour augmentation with guided bone regeneration was performed using synthetic bone particles (maxresorb®) and an ADM (mucoderm®). Keratinized mucosa width (KMW) and gingival thickness (GT) were assessed at baseline, 1, 3, 6, 12 and 24 months. Marginal bone loss, probing pocket depth, bleeding on probing and plaque index were also recorded. GT and KMW increased between baseline and 1 month, slightly decreased between 1 month and 12 months (P < 0.001) and remained stable between 12 and 24 months (P < 0.001). After 2 years, mean marginal bone loss level was 0.51 ± 0.63 mm, with no probing pocket depth values >5 mm and no concomitant signs of inflammation registered. Pink aesthetic score was 8.3. Combining an ADM and guided bone regeneration with early implant placement revealed a significant increase of 1.9 mm for GT and 1.6 mm for KMW after 2 years, showing good patient satisfaction regarding the aesthetic outcomes of soft tissues and prosthetic crown.     

Three-dimensional measurement of radiographic bone–implant contact lengths of zygomatic implants in zygomatic bone: a retrospective study of 66 implants in 28 patients

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.     

Healing masseter entheses of mandibular reconstruction with autograft—Raman spectroscopic and histological study

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 (r_spearman = 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.     

Oromandibular reconstruction using microvascularized bone flap: report of 1038 cases from a single institution

This retrospective study was performed to review 1038 patients who underwent mandibular reconstruction with free vascularized bone flaps at a single institution between 2006 and 2017. Of these patients, 827 (79.67%) had fibula flaps, 197 (18.98%) had deep circumflex iliac artery perforator (DCIA) flaps, and 11 (1.06%) had scapula bone flaps. The most common pathological diagnosis was ameloblastoma (n = 366, 35.26%), followed by squamous cell carcinoma (n = 278, 26.78%) and osteoradionecrosis (n = 152, 14.64%). Fifty-seven patients (5.49%) had major complications requiring surgical intervention and one patient died of a pulmonary embolism. Venous crisis was the most frequent major complication (n = 20, 1.93%), followed by haematoma (n = 17, 1.64%) and flap necrosis (n = 14, 1.35%). One-stage mandibular reconstruction was preferred whenever possible, as this generally decreases the financial and hospitalization burden. The four-segment method of jaw reconstruction appeared to achieve good aesthetic appearance results in Asian patients and this was not associated with a higher risk of segment ischemia compared with the three-segment method.