Implant Dentistry最新文献

Purpose: Pixel values from cone-beam computed tomography (CBCT) are proportional to bone density. This study aimed to correlate and compare pixel values of healed maxillary sinus grafts and adjacent native bone (NB).

Material and methods: This study was conducted on CBCT scan patients referred for maxillary sinus floor augmentation with biphasic calcium phosphate (n = 31). Graft height and width measurements were performed. In addition, mean pixel values were calculated in 3 different regions: NB, sinus graft close to NB (CNB), and sinus graft far from NB (FNB). Micro-CT and histological analyses of bone specimens of a representative case were also performed.

Results: Significant correlations were found between CNB and graft height (r = 0.41; P < 0.021); and FNB and graft width (r = 0.519, P < 0.003). In addition, pixel values from both graft groups (CNB and FNB) differed significantly (P < 0.001). Finally, histological sections revealed smaller areas with newly formed bone in the FNB area.

Conclusions: Within the limitations of this study, the present findings suggest that pixel values of sinus grafted areas are directly correlated with the extension of the grafted area.

Purpose: Hydroxyapatite treated with recombinant human bone morphogenetic protein-2/Hydroxyapatite (rhBMP-2/HA) or bovine bone was applied on extraction sockets for alveolar ridge preservation, and the results were compared with respect to clinical and histological bone formation.

Materials and methods: This was a prospective, randomized controlled clinical trial performed on 20 implant placement sites (10 in the experimental and 10 in the control group). rhBMP-2/HA was applied on extraction sockets in the experimental group and bovine bone on those of the control group. The bone at the corresponding sites was biopsied 3 months later, and clinical, histological, and histomorphometric analyses were performed.

Results: The alveolar bone height was well preserved in both groups with relatively less change in width in the experimental group compared with the control group. The percentage of new bone was 25.37% ± 17.23% in the experimental group and 6.13% ± 4.32% in the control group; the difference was statistically significant.

Conclusions: The alveolar ridge was preserved clinically and histologically in both groups. rhBMP-2/HA resulted in greater new bone formation than bovine bone 3 months after the surgery.

Purpose: This study aimed to compare in vivo osteogenesis on rough threaded dental implants with and without calcium phosphate (CaP) coating deposition, alone or in association with low-level laser therapy (LLLT) by gallium aluminum arsenide.

Material and methods: Four groups were studied: G1: implant; G2: implant + CaP coating; G3: implant + LLLT; and G4: implant + CaP coating + LLLT. LLLT was applied for 7 days at the surgical site before and after placing the implant. Topographic characterization was performed before surgery using scanning electron microscopy and energy dispersion spectrophotometry. Bone-implant contact (BIC) was measured after 1, 2, and 6 weeks and reverse torque after 6 weeks. In short periods, G2, G3, and G4 showed significantly greater BIC than G1 (P < 0.05), but no difference in BIC was observed at 6 weeks. However, the values for the removal torque test at 6 weeks were higher in G2 and G4 (P < 0.05).

Conclusion: Both CaP coating alone and using LLLT induce cellular stimulation and improve BIC in short-term healing, resulting in higher implant fixation, and should be considered in clinical practice due to their low cost and high effectiveness.

Purpose: To evaluate the outcome of single postextraction immediate implants placed with and without bone grafts in the esthetic maxillary premolar area for 3-year follow-up after loading.

Material and methods: After tooth extraction, 102 patients received 115 immediate dental implants. Patients were randomly allocated to immediate implant placement with (group A: 51) or without (group B: 51) anorganic bovine bone and resorbable collagen barrier.

Results: After 3 years (T36), 1 implant failed in each group. Thirty-seven patients showed inflammation and bleeding, 19 mucositis, and 2 periimplantitis. Statistical significant association was found between BOP and mucositis at T12 (P < 0.0005) and T36 (P < 0.0005). The mesial bone level was -0.61 mm in group B and -1.01 mm in group A (P < 0.001). The group B distal bone level was -0.71 mm and -1.12 mm in group A (P < 0.005). Group B's buccal mean probing was increased (+0.40 mm) than group A (+0.36 mm). Group B's palatal mean value was higher (+0.54 mm) than group A (+0.38 mm). No statistically significant differences were found between the 2 groups. However, the Pink Esthetic Score and patient satisfaction were higher in group B than A (P < 0.001).

Conclusions: The use of anorganic bovine bone substitute with a resorbable collagen barrier in immediate postextractive implants seems to improve the esthetic outcomes after a 3-year follow-up.

Purpose: To compare hard- and soft-tissue changes around immediate implants connected with 2 types of healing abutments during the early phases of healing.

Materials and methods: Twenty-eight immediate implants were placed into molar/premolar sockets through a modified osteotomy method. The gaps around implants were grafted with deproteinized bovine bone mineral. According to the size of the alveoli, the implants were connected with titanium healing abutments (traditional group) or customized healing abutments (CA group). Radiographic and intraoral examinations were performed before surgery, postoperatively, and at the 6-month recall.

Results: Buccal (P = 0.717) and lingual (P = 0.087) vertical bone loss was comparable between groups. More significant incomplete defect fill was found at the distal aspect of the CA group (P = 0.000). The buccal bone thickness alterations were similar between the 2 groups (P = 0.902 at the implant platform). The mid-facial soft-tissue level was well maintained in both groups.

Conclusions: Within the limitations of this study, for immediate implants placed into posterior sockets, customized healing abutments can facilitate closure of large sockets. Despite more pronounced incomplete defect fill, healing abutments consisting of polyether ether ketone and resin did not render an increased risk for periimplant bone loss or soft-tissue recession during the early healing period.

Purpose: To introduce a novel modality that enables the measurement of forces applied during a transalveolar sinus floor elevation (tSFE) and to investigate the influence of anatomical and surgical factors on the necessitated force in sinus membrane detachment.

Material and methods: A new endosinus probe, innovated with a calibrated load cell, was used to test the forces needed to perforate ten maxillary sinuses in 5 human cadavers. The same probe was also used to detach the Schneiderian membrane from the bony floor of 21 human subjects undergoing tSFE.

Results: The force needed to cause membrane perforation in the cadaver sample was on average 3.46 ± 1.04 N. The maximum force applied in vivo to a sinus membrane without perforation was 2.01 ± 0.67 N on average. Regression analysis showed that smoking (P < 0.001), as well as 3.0 mm osteotomy (P < 0.001), was significantly correlated to increased forces during membrane detachment.

Conclusions: The maximum force needed to detach the membrane was found to be, on average, lower than the membrane breaking load in cadavers. Furthermore, because of smoking and a 3.0-mm osteotomy diameter demonstrating a high association with increased forces during membrane detachment, they may be considered as risk factors of membrane perforation.

Purpose: This case presentation and retrospective review of cone-beam computed tomograms is to evaluate prevalence, classification, and demographics of bifid mandibular canals (BMC) to inform practitioners on this variation and avoid untoward complications due to failure to diagnose.

Materials and methods: Two thousand one hundred thirty scans were evaluated by 2 oral and maxillofacial radiologists. BMCs were noted and classified according to Naitoh. Demographic data were also collected and analyzed.

Results: Twenty-eight patients were noted to have bifid mandibular canal, with an average age of 39 years (± 19.5), with no strong sex predilection. Patients (1.31%) were noted to have bifid canals. A greater percentage of patients were shown to have bilateral bifid canals (42.9%) versus either unilateral side (25% left, 32.1% right), but is statistically insignificant. Prevalence was greatest in types 1 and 3 (35.9% and 51.3%, respectively, P = 0.000011). Types 2 and 4 were much less common.

Conclusion: BMCs are an important anatomic variation that has implications on any mandibular surgery, including implant surgery. Just more than 1% of patients have this variation, but failure to recognize this in a patient can result in poor outcome, as illustrated in the case presented.

Purpose: The impact of hyperbaric oxygen (HBO) on the healing of bone tissues around implants was studied using an animal model.

Methods: A total of 32 beagle dogs were selected and randomly divided into the HBO group and the blank group. The dogs in the HBO group were subjected to 90 minutes of HBO therapy. X-ray, cone-beam computerized tomography imaging, implant stability quotient (ISQ) values, histological observation, quantitative analysis of bone histomorphometry, and hematoxylin-eosin (HE) and Masson staining were evaluated.

Results: In this study, at 4 weeks after the surgery, the mean ISQ value in the HBO group was higher than that in the blank group, and the difference had statistical significance (P < 0.05). At week 4 and 8, the mean values of bone ingrowth fraction (BIC%) and the percentage of bone area (BA%) in the HBO group were both higher than those of the blank group. Decalcified paraffin sections were stained with HE and Masson staining showed that the bone tissue around the implant in the HBO group has more osteoblasts than control group, and many irregular marrow cavities and Haversian bone plates were observed in the new bone tissue.

Conclusion: This study showed that after implantation, early osteogenesis was better in the HBO group than in the blank group. On one hand, the healing time of the bone tissue around the implants was reduced.