The Effect of Initial Biologic Width on Marginal Bone Loss: A Retrospective Study.

PURPOSE: To evaluate the short-term effect of dental implant placement, mucosa thickness, and their combined effects (initial biologic width) on marginal bone loss. MATERIALS AND METHODS: This was a retrospective study on patients who received implant surgery in the posterior region without bone augmentation surgery between 2012 and 2016, and implants had been loaded for more than 12 months. Each patient received radiographic examination before and after implant surgery, before the stage-two surgery, and during the 1- to 5-year follow-up. The thickness of mucosa, depth of dental implant placement, and crestal bone loss were evaluated on digital radiographs. The interaction was discussed by defining the combination of initial mucosal thickness and implantation depth as the initial biologic width. The implants were divided into four study groups based on the quartile of the initial biologic width. RESULTS: This study included 266 patients (94 male and 172 female, 22 to 85 years of age, mean age: 51.43 years), with 413 dental implants placed including 239 Straumann implants and 174 Ankylos implants. The average follow-up was 21.50 months. After 1 to 5 years, the median crestal bone loss around implants was 0.35 mm (0.30 mm for Straumann BL and 0.40 mm for Ankylos). The implants were divided into four groups: group A (≤ 2.85 mm), group B (2.85 to 3.40 mm), group C (3.40 to 3.97 mm), and group D (> 3.97 mm). Group B showed significantly less crestal bone loss than group A (0.38 mm vs 0.25 mm; P < .05) and group C (0.25 mm vs 0.40 mm; P < .05) during the follow-up. Significantly more crestal bone loss around implants was observed in the thin mucosa group than in the thick mucosa group (0.50 mm vs 0.30 mm; P < .001), while implants placed beneath the bone level displayed a significantly higher amount of marginal bone loss than implants placed even with the bone crest (0.50 mm vs 0.10 mm; P < .001). CONCLUSION: The initial biologic width has an effect on crestal bone loss. When the initial biologic width was between 2.85 and 3.40 mm, the marginal bone loss was lowest. Based on radiographic evaluation, implants placed in thick gingiva and even with the bone level showed less alveolar marginal bone loss compared with implants placed in thin gingiva and below the crestal bone level.

Peri-implant marginal bone changes with implant-supported metal-ceramic or monolithic zirconia single crowns: A retrospective clinical study of 1 to 5 years.

STATEMENT OF PROBLEM: Monolithic zirconia has excellent mechanical and biologic properties. However, evidence of the clinical properties of implant-supported monolithic zirconia prostheses is limited. PURPOSE: The purpose of this retrospective clinical study was to compare the peri-implant marginal bone changes of metal-ceramic and monolithic zirconia single crowns in the posterior region after prosthetic loading. MATERIAL AND METHODS: A total of 224 participants treated with 327 implants restored with either metal-ceramic or monolithic zirconia single crowns in the posterior region between 2012 and 2016 were included in this study. Clinical outcomes, including the plaque index, peri-implant probing depth, and bleeding on probing, were recorded, and the marginal bone level was recorded by using the panoramic radiographs obtained at implant placement, second-stage surgery, and the most recent follow-up visit. The included parameters were analyzed with the nonparametric Mann-Whitney tests (α=.05). RESULTS: The mean follow-up time was 30.4 months, and the cumulative survival rate of implants was 100% and that of the prostheses was 99.1%. The plaque index was 0.46 in the metal-ceramic group, which was significantly higher (P<.05) than 0.37 in the monolithic zirconia group. However, no significant differences (P>.05) were observed in peri-implant probing depth and bleeding on probing between the 2 groups. The marginal bone level at implant placement, second-stage surgery, and the most recent follow-up visit was above the implant platform in both the metal-ceramic and monolithic zirconia groups. The marginal bone changes of the metal-ceramic group was 0.31 mm in the healing period and 0.38 mm in the prosthetic loading period, while in the monolithic zirconia group, it was 0.25 mm in the healing period and 0.43 mm in the prosthetic loading period; no significant differences (P>.05) were observed between the 2 groups. CONCLUSIONS: The peri-implant marginal bone level change was comparable after prosthetic loading for metal-ceramic and monolithic zirconia single crowns, although monolithic zirconia was associated with reduced plaque.

Responses of Sinus Membrane and Antral Pseudocyst Following Lateral Window Sinus Augmentation with Bone Grafting: A Retrospective Study.

PURPOSE: To investigate the influence of lateral window sinus augmentation on sinus physiology, including sinus membrane thickness and the outcome of antral pseudocysts. MATERIALS AND METHODS: This retrospective study was performed by reviewing all lateral window sinus augmentation procedures, which were done between the years 2013 and 2015. Each enrolled patient had CBCT images preoperatively (T0), immediately postoperatively (T1), and 6 months postoperatively (T2). The sinus membrane thickness, pseudocyst dimensions, and intraoperative perforation were evaluated. Patient-related factors such as age and sex that could influence the mucosal properties were also analyzed. RESULTS: Based on established inclusion criteria, 306 patients with 320 sinuses were included in this study. The overall mean thickness of the sinus membrane (T0) was 1.30 ± 1.08 mm, and membrane thickening (> 2 mm) was observed in 22.19% of the sinuses. Preexisting pseudocysts were identified in 24 sinuses (7.50%), most of which remained unchanged or disappeared after 6 months. The intraoperative membrane perforation rate was lowest (1.96%) when the membrane thickness was 1.0 to 1.5 mm, and the perforation rate was increased in patients with thickened (> 2 mm) or thinned (≤ 1 mm) membrane. Membranes swelled immediately after operation (T1 vs T0, P < .01) and gradually recovered at 6 months. No significant change in membrane thickness was shown after the sinus augmentation procedure in the perforation group and pseudocyst group. The mean thickness of the sinus membrane at T0 and T1 was significantly higher for male subjects (P < .01). CONCLUSION: Lateral window sinus augmentation has little or no impact on sinus membrane thickness and antral pseudocysts after a 6-month healing period, except for a transient mild membrane swelling. Thickened and thinned membrane were risk factors for intraoperative perforation. Small-sized perforation and pseudocysts might not contraindicate sinus augmentation from the standpoint of the surgical impact on the sinus membrane.

Effects of strontium-incorporated micro/nano rough titanium surfaces on osseointegration via modulating polarization of macrophages.

Macrophages perform multiple functions in both inflammation and wound healing, and are one of the fore front cells during implant osseointegration that influence subsequent process. Essential trace element modification may effectively modulate titanium implant surface biological properties. In this work, strontium (Sr) incorporated micro/nano rough titanium surfaces (Sr-SLA) was fabricated by hydrothermal treatment, and immunoreaction of macrophages was further investigated. In vitro results revealed that Sr doping inhibited inflammatory response of macrophages, further attenuated the inhibitory effect on following bone marrow derived cells (BMSCs) osteogenic differentiation. The regulation of macrophages by Sr-SLA likely involved ERK signaling pathway. Consistently, the in vivo study showed that compared with titanium surface sand-blasted with large grit and double acid-etched (SLA) implants, Sr-SLA implants could enhance new bone formation accompanied with more alternatively activated M2 macrophages infiltration and less classically activated M1 macrophages infiltration. These results reveal the immunomodulatory ability of Sr-SLA of adjusting the functional status of macrophages through inhibiting M1 polarization while promoting M2 polarization.

Clinical evaluation of xenogeneic collagen matrix versus free gingival grafts for keratinized mucosa augmentation around dental implants: A randomized controlled clinical trial.

AIM: To evaluate the outcomes of an apically repositioned flap (ARF) plus xenogeneic collagen matrix (XCM) in augmenting keratinized mucosa width (KMW) around dental implants when compared with ARF plus free gingival grafts (FGG). MATERIALS AND METHODS: Twenty-six participants with at least one site with KMW ≤2 mm were randomized into FGG or XCM group. Clinical examinations were performed at baseline and at 2 and 6 months after surgery, including KMW, keratinized mucosa thickness, gingival index (GI), and probing depth (PD). Post-operative pain and patient satisfaction were also evaluated. RESULTS: At 6 months, FGG attained a greater increase of KMW and thicker mucosa than XCM (4.1 ± 1.6 mm vs. 1.8 ± 1.0 mm, p < .001; 1.7 ± 0.6 mm vs. 1.2 ± 0.3 mm, p < .01). Regarding GI, PD, post-operative pain, aesthetic outcomes, and patient satisfaction, no significant difference could be detected. Moreover, the operation time of XCM group was shorter (60 ± 9 min vs. 39 ± 8 min, p < .001). CONCLUSIONS: FGG could result in greater increase of KMW than XCM, though both could increase KMW, maintain peri-implant health, and attain comparable aesthetic outcomes. The use of XCM was associated with reduced operation time.

Gingival Plasma Cell Granuloma: A case Report of Multiple Lesions.

BACKGROUND: Plasma cell granuloma (PCG) is a rare benign pseudotumorous proliferation of unclear etiology that is mainly situated in the lungs. Gingival PCG is an even more peculiar lesion that usually occurs in middle-aged or elderly individuals and clinically manifests as a solitary entity. CASE REPORT: A 15-year-old male with no underlying medical conditions presented with multiple gingival masses in the right maxilla, which were initially thought to be epulis. The lesions were resected completely and the excisional biopsies sent for histological examination. Immunohistochemical (IHC) stain revealed dense polyclonal plasma cell infiltration with positive expression of both kappa and lambda light chains, confirming a diagnosis of gingival PCG. Subsequently, the affected gingiva healed uneventfully, with no sign of recurrence over 2 years of follow-up. CONCLUSIONS: The present report depicts an extremely unusual case of gingival PCG occurring in a juvenile with multiple lesions, which is worth attention in clinical pediatric dentistry. Excisional-biopsy and histological investigations are imperative for a confirmative diagnosis and to exclude potential aggressive conditions. Complete resection of lesions seems to be a valid treatment, while long-term clinical follow-up is still needed.

Biomechanical and Morphometric Evaluation of a Strontium-Incorporated Implant and Four Commercially Available Implants: A Study in Rabbits.

PURPOSE: Strontium has shown a positive effect on osseointegration in experiments. This study compared surface characterization and osseointegration of a strontium-incorporated implant with four commercial implants with different surface treatments. MATERIALS AND METHODS: A strontium-oxide layer was created by hydrothermal treatment on the surface of the implant (SLA-Sr). Surface characterizations were observed using a scanning electron microscope, three-dimensional (3D) optical microscope, and x-ray energy-dispersive spectrometry. Implants of different surface treatments including resorbable blasting media (RBM), sandblasting with large grit and acid etching (SLA-1, SLA-2), sandblasting and thermal acid etching (STA), and SLA-Sr were implanted into the proximal tibiae and femoral condyles of rabbits. Biologic effects were evaluated by removal torque testing and histomorphometric analysis after 3, 6, and 12 weeks of implantation. RESULTS: Nanostructures were observed on the surface of SLA-Sr and STA. Calcium (Ca) was detected on the surface of RBM. Sr was detected on the surface of SLA-Sr. SLA-1 and STA had greater surface roughness than SLA-2, SLA-Sr, and RBM (P < .05). In vivo, SLA-Sr achieved better removal torque value (RTV) than that of RBM and SLA-2 at 3 weeks (P < .05), as well as increased bone area ratio (BA%) in cortical bone compared with RBM at 3 weeks (P < .05). STA showed higher bone-to-implant contact ratio (BIC%) in cortical bone than RBM at 3 and 6 weeks (P < .05). Compared with RBM, SLA-1 had better RTV at 6 weeks and higher BIC% in cortical bone at 12 weeks (P < .05). CONCLUSION: In vivo, compared with SLA-2 and RBM, the implant with the strontium-oxide layer displayed slight advantages in new bone formation and osseointegration in the early healing stage. In the later osseointegration stage, the results of SLA-Sr were comparable with other implants.

[Reliability and validity of the Chinese version of the 5-item oral health impact profile].

OBJECTIVE: To evaluate the reliability and validity of the Chinese version of the 5-item oral health impact profile (OHIP-5). METHODS: According to the international guidelines, the Chinese version of the OHIP-5 was produced. It was applied to patients who visit our clinic. The reliability of the scale was evaluated by internal consistency reliability and test-retest reliability. In addition, the validity of the scale was evaluated by construct validity and convergent validity. RESULTS: A total of 556 patients were enrolled in the study. The Cronbach's alpha and the intraclass correlation coefficient values (ICC) of the Chinese version of the OHIP-5 were 0.868, 0.831, respectively. The results of the confirmatory factor analysis (CFA) showed that the one-factor model provided an acceptable fit to the data. The fit indices were: the chi-square fit statistics/degree of freedom (χ²/df)=2.419, the goodness-of-fit index (GFI)=0.995, the adjusted goodness of fit index (AGFI)= 0.960, the normed fit index (NFI)=0.996, the incremental fit index (IFI)=0.997, the Tucker-Lewis index (TLI)= 0.985, the comparative fit index (CFI)=0.997, and the root mean square error of approximation (RMSEA)=0.070. For the convergent validity of the scale, the Spearman's rank correlation coefficient was 0.674. CONCLUSIONS: The Chinese version of OHIP-5 had a good reliability and validity by rigorous psychometric properties. Overall, it can be further promoted in clinical research and epidemiological investigations.

The optimization of sintering treatment on bovine-derived bone grafts for bone regeneration: in vitro and in vivo evaluation.

Modifications of sintering temperature and treatment time of bovine-derived bone grafts affect their physicochemical properties and further influence biological activity. Three different temperature sintered bovine-derived bone grafts: group I (300 °C 3 h), group II (300 °C 3 h plus 530 °C 6 h), and group III (300 °C 3 h plus 1000 °C 2 h) and Bio-Oss® were characterized and then compared in vitro for their effects on bone marrow stromal cells (BMSCs) migration, proliferation, and differentiation as estimated by cell migration assay, Alkaline phosphatase (ALP) activity assay, and Alizarin red staining. Further, the four bone grafts were implanted into the calvarial defects of rabbits to evaluate bone regeneration and graft degradation. The four deproteinized bovine-derived bone grafts displayed different surface topography. Group II displayed the highest potential of attracting cells. Both groups I and II markedly promote BMSCs differentiation. After 6 and 12 weeks, defects grafted with groups I and II displayed a significant higher bone fraction than defects grafted with group III and Bio-Oss®. Bone graft remnants remained in all four groups. Taken together, sintering at 300 °C for 3 h and sintering at 300 °C for 3 h with an addition of 530 °C for 6 h of bovine-dervied bone grafts displayed potential use in bone regeneration. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:272-281, 2020.

Physiochemical characterization and biological effect of anorganic bovine bone matrix and organic-containing bovine bone matrix in comparison with Bio-Oss in rabbits.

Bovine origin matrix has been widely used in clinical applications and investigated by various research institutions. However, the potential factors that influence bone regeneration are still not thoroughly understood and need further investigations. In this study, bone regeneration properties of anorganic bovine bone matrix (ABBM), organic-containing bovine bone matrix (OBBM), and widely acknowledged anorganic bovine bone matrix (Bio-Oss) were compared. Besides, the correlations between physiochemical characterizations and bone regeneration properties of the three xenografts were also investigated. Physiochemical characterizations were measured by special instrumentations. In animal studies, the three xenografts were implanted into 8-mm-diameter cranial defects of 16 New Zealand white rabbits. The biological effects were evaluated by micro-computed tomography and histomorphometric analysis after 6 and 12 weeks of implantation. The physical characterizations showed that anorganic bovine bone matrix and Bio-Oss had more nanostructures, larger surface area, bigger pore volume, and bigger pore size than that of organic-containing bovine bone matrix. The chemical characterizations showed that anorganic bovine bone matrix and Bio-Oss had higher crystallinity than that of organic-containing bovine bone matrix, and organic-containing bovine bone matrix contained organic nitrogen (N) component. In vivo, anorganic bovine bone matrix and Bio-Oss possessed better bone regeneration properties than that of organic-containing bovine bone matrix. Taken together, nanostructures, larger surface area, bigger pore volume, and bigger pore size of xenografts played an active role in new bone formation. Besides, lower crystallinity and organic N element of xenografts produced a positive effect on graft degradation. The abovementioned findings could provide theoretical basis for better choice in clinical applications and better manufacturing hydroxyapatite-derived bone graft in the future.

The effects of Sr-incorporated micro/nano rough titanium surface on rBMSC migration and osteogenic differentiation for rapid osteointegration.

Recruitment of endogenous bone marrow-derived mesenchymal stem cells (BMSCs) has been widely discussed as an alternative strategy for bone regeneration. Strontium (Sr) is known to direct the BMSCs' commitment to the bone lineage and encourage bone formation; however, the underlying mechanisms remain elusive. In this study, an Sr-incorporated micro/nano rough titanium surface (MNT-Sr) was fabricated by hydrothermal treatment in an attempt to facilitate BMSCs' recruitment and their osteogenic differentiation to enhance rapid osseointegration. Micro rough titanium (MT) was set as the control biomaterial. In vitro, MNT-Sr and its extracts promoted the migration and osteogenic differentiation of BMSCs. In animal studies, green fluorescent protein (GFP)-labeled BMSCs were intravenously injected into wild-type rats for tracing before tibial implantation surgery. The GFP+BMSC recruitment to the implantation site was successfully triggered by MNT-Sr implantation. A trend for increased bone area (BA%), bone-implant contact (BIC%) and removal torque values (RTVs) was observed for the MNT-Sr implant compared to that observed for MT at 2 weeks. Advanced mechanism analysis indicated that Sr2+ enhanced the SDF-1α/CXCR4 signaling pathway both in vitro and in vivo. Taken together, these findings suggest that MNT-Sr has promising therapeutic potential for future use in dental implants by homing endogenous stem cells to stimulate bone regeneration.

Influence of Lateral Windows with Decreased Vertical Height Following Maxillary Sinus Floor Augmentation: A 1-year Clinical and Radiographic Study.

PURPOSE: To verify whether lateral sinus floor elevation (LSFE) with the vertical height of the osteotomy decreased to 3 to 5 mm can achieve improvement compared with a conventional lateral window in terms of implant survival, graft stability, and related complications. MATERIALS AND METHODS: Of the 49 patients who were selected for inclusion in this retrospective study, 25 patients were in the test group and 24 were in the control group based on the vertical height of the lateral window. Each patient received the LSFE treatment using deproteinized bovine bone mineral (DBBM) based on the two different vertical heights of the lateral window (test group: 3 to 5 mm; control group: 6 to 8 mm in vertical height). Residual bone dimensions were measured preoperatively, and graft dimensions were measured immediately after the procedure (baseline), 6 months (T1), and 1 year (T2) postoperatively on the basis of cone beam computed tomography (CBCT) scans. CBCT scan data at the baseline were analyzed with image processing software to evaluate the volume of augmented material, and they were transformed into three-dimensional reconstruction images to calibrate the window dimension. Implant failure and recorded intraoperative and postoperative complications were counted. RESULTS: A prominent augmented graft height was obtained in both groups (test group: 9.48 ± 3.27 mm; control group: 10.44 ± 3.01 mm) with no significant difference; likewise, no difference was observed concerning augmented graft volume. Neither cumulative survival rate (CSR) nor augmented graft height decrement had any statistical intergroup difference during each follow-up interval. CSRs were detected as 100% for the test group and 94.28% and 91.67% for the control group based on implants and patients, respectively. Intraoperative membrane perforation was reported in two cases with a few nosebleeds the first night in the test group, while one case occurred in the control group. All the perforations were successfully sealed intraoperatively by a collagen membrane. CONCLUSION: Osteotomy of LSFE with decreased vertical height yielded similar results to the control group with conventional dimensions in terms of implant survival, graft stability, and related complications with 1 year of follow-up. Notwithstanding, a prospective split-mouth randomized controlled trial with long-term observation is imperative to further investigate the influence of decreased vertical height of the lateral window on maturation and consolidation of DBBM.

Positive effect of strontium-oxide layer on the osseointegration of moderately rough titanium surface in non-osteoporotic rabbits.

OBJECTIVES: To evaluate the effect of strontium-oxide layer on new bone formation and osseointegration of sandblasted large-grit double-acid-etched (SLA) implant. MATERIAL AND METHODS: Strontium-oxide layer on the SLA surface was produced by hydrothermal treatment using a Sr-containing solution. The surface topographies, roughness, hardness values, chemical elements and ionic release of SLA and the strontium-containing SLA (Sr-SLA) surface were measured by special instruments separately. Sixty-four SLA and Sr-SLA implants were inserted into the proximal tibiae and femoral condyles of sixteen non-osteoporotic New Zealand white rabbits. The biological effects were evaluated by removal torque (RTQ) testing and histomorphometric analysis after 3 and 6 weeks of implantation. RESULTS: The surface characteristics showed Sr-SLA surfaces with dotted nanostructures can release appropriate amount of strontium ions into surrounding tissue till 14 days. In vivo, the Sr-SLA implants presented significantly higher RTQ than SLA implants at 3 and 6 weeks (P < 0.05). The Sr-SLA implants presented higher bone-to-implant contact (BIC) than SLA implants in cortical bone at 3 and 6 weeks (P < 0.05). The bone area was slightly higher for the Sr-SLA implants at 3 and 6 weeks (P > 0.05). CONCLUSIONS: The strontium-oxide layer on the SLA surface has the potential to improve implant osseointegration in non-osteoporotic rabbits.

The Characterization and Osteogenic Activity of Nanostructured Strontium-Containing Oxide Layers on Titanium Surfaces.

PURPOSE: The aim of this study was to compare strontium-containing implant (Sr-Ti) surfaces with modified pure Ti (Mod Ti) on the promotion of osteogenesis in vitro and in vivo. MATERIALS AND METHODS: The Sr-Ti surfaces were fabricated by hydrothermal treatment. The Mod Ti surfaces were used as a control. These surfaces were characterized with scanning electron microscopy, x-ray diffractometer, and x-ray photoelectron spectroscopy. The biologic activity was analyzed by initial adhesion, proliferation, alkaline phosphatase (ALP), osteocalcin, and osteogenesis-related genes in vitro. Hematoxylin and eosin (H&E) staining and immunohistochemistry analysis of tissue adjacent to this implant were used to evaluate osteogenic activity in vivo. RESULTS: The results confirmed multiple nanogranules on the Sr-Ti surface composed of well-crystallized TiO2 and SrTiO3 phases. Long-term release of Sr enhanced mesenchymal stem cell (MSC) initial adhesion, the production of ALP, osteocalcin, and upregulated osteogenesis-related genes. For in vivo osteogenic evaluation, mesenchymal-like cells were adhered on these two surfaces under the electron microscope and transitory hematoma in adjacent bone tissue by H&E staining. The Stro-1-labeled MSCs were noted around the Sr-Ti surface in immunohistochemistry analysis. CONCLUSION: This study suggests that Sr-Ti surfaces with nanostructures could promote the response of MSCs in vitro, and recruit Stro-1 labeled MSCs in vivo.

Long-term outcomes of osteotome sinus floor elevation without bone grafts: a clinical retrospective study of 4-9 years.

OBJECTIVE: To evaluate the long-term clinical and radiographic outcomes of dental implant placed using osteotome sinus floor elevation (OSFE) without bone grafts, and to analyze the potential influence factors of implant survival and endo-sinus bone remodeling. MATERIAL AND METHODS: A retrospective study design was adopted. The clinical and radiographic data of 96 implants in 80 patients were collected after 4-9 (mean 5.40) years follow-up. Implant failures, peri-implant marginal bone loss (MBL), and endo-sinus bone remodeling on the radiographs were evaluated. A life-table analysis was used to assess the implant survival. Statistical models were established to investigate the potential influence factors of implant survival and endo-sinus bone gain (ESBG). RESULTS: In total, nine implants in seven patients failed, giving the 9-year cumulative survival rates of 90.6% and 91.3% for implant-based analysis and patient-based analysis, respectively. The mean MBL between implant installation and the 4- and 9-year follow-up visit was 0.46 ± 0.88 and 0.50 ± 1.69 mm, respectively. The average ESBG on radiographs was 2.95 ± 1.25 and 2.16 ± 1.13 mm at the 4- and 9-year follow-up. The final ESBG was found to be positively correlated to implant protrusion length after surgery without any other factors related. The implant survival rate was significantly lower in severe atrophic site (residual bone height <5 mm). CONCLUSION: Osteotome sinus floor elevation without bone grafts is a predictable treatment modality in the long run. But it should be used with caution when the initial bone height of the edentulous site is lower than 5 mm. The final endo-sinus bone height was found to be positively correlated to implant protrusion length measured on radiographs immediately after implant installation.

Effects of storage medium and UV photofunctionalization on time-related changes of titanium surface characteristics and biocompatibility.

Storage in aqueous solution and ultraviolet (UV) photofunctionalization are two applicable methods to overcome the biological aging and increase the bioactivity of titanium. As information regarding the combined effects of storage medium and UV photofunctionalization has never been found in published literatures, this study focused on whether appropriate storage methods and UV photofunctionalization have synergistic effects on the biological properties of aged titanium surfaces. Titanium plates and discs were sandblasted and acid etched and then further prepared in five different modes as using different storage mediums (air or dH2 O) for 4 weeks and then with or without UV treatment. The surface characteristics were evaluated with scanning electron microscopy, contact angle measurements, and X-ray photoelectron spectroscopy. MC3T3-E1 cells were cultured on the surfaces, and cellular morphology, proliferation, alkaline phosphatase activity, and osteocalcin release were evaluated. The results showed that nanostructures were observed on water-stored titanium surfaces with a size of about 15 × 20 nm(2) . UV treatment was effective to remove the hydrocarbon contamination on titanium surfaces stored in either air or water. UV photofunctionalization further enhanced the already increased bioactivity of modSLA on initial cell attachment, proliferation, alkaline phosphatase activity, and osteocalcin release. Overall, UV photofunctionalization was effective in further enhancing the already increased bioactivity by using dH2 O as storage medium, and the effect of UV treatment was much more overwhelming than that of the storage medium. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 932-940, 2016.

Osteogenesis of rat mesenchymal stem cells and osteoblastic cells on strontium-doped nanohydroxyapatite-coated titanium surfaces.

PURPOSE: The aim of this study was to compare the promotion of osteogenesis in vitro on three types of titanium surfaces: a strontium-hydroxyapatite (Sr-HA)-coated surface, a nano-HA-coated surface, and an uncoated roughened surface. MATERIALS AND METHODS: Sr-HA and HA were placed on disks with a roughened titanium surface by electrochemical deposition. MC3T3-E1 preosteoblast cells and rat bone mesenchymal stem cells were cultured on the Sr-HA, HA-coated, and uncoated roughened disks, and cell adhesion, proliferation, viability, osteogenic differentiation, and formation of mineralized nodules were measured at various time points. RESULTS: The Sr-HA coating produced by a simple electrochemical deposition treatment evidently enhanced the attachment, spreading, alkaline phosphatase activity, and extracellular matrix calcium mineralization of mouse bone mesenchymal stem cells and MC3T3-E1 cells compared with an untreated roughened titanium surface and a nano-HA-coated surface. CONCLUSION: This study suggests that a Sr-doped nano-HA coating produced through electrochemical deposition improves the osteoconductivity of a microrough titanium surface.

Analysis of facial bone wall dimensions and sagittal root position in the maxillary esthetic zone: a retrospective study using cone beam computed tomography.

PURPOSE: To determine the thickness of the facial bone wall and the sagittal angulation between the long axis of the teeth and the long axis of the associated alveolar bone in the maxillary esthetic zone using cone beam computed tomography (CBCT). MATERIALS AND METHODS: A retrospective radiographic study of CBCT images was conducted in 300 patients. The distance between the cementoenamel junction (CEJ) and the facial bone crest, the thickness of the facial bone wall (4 mm apical to the CEJ and midroot), and the sagittal angle between the long axis of teeth and the long axis of the respective alveolar bone were measured. Descriptive statistics and frequency analyses were performed. RESULTS: The sample included 133 men and 167 women (mean age, 36.9 years; range, 18 to 60 years). The distance between the CEJ and the facial bone crest varied between 0.1 and 4 mm and showed an overall tendency to increase with age. Almost 80% of anterior teeth and 40% of premolars exhibited a thin facial bone wall (< 1 mm), and nearly 30% of sites had a bone wall thinner than 0.5 mm. The sagittal angle at approximately 80% of central incisor and second premolar sites was < 20 degrees, but the angle at more than 40% of canine sites was ≥ 30 degrees. There was a significant decrease in facial bone wall thickness from premolars to anterior teeth. CONCLUSION: The facial bone wall in most maxillary anterior teeth was very thin. There was a substantial sagittal angulation between the long axes of teeth and those of their respective alveolar bone in most esthetic zone positions. CBCT analyses of the facial bone wall and the sagittal angle are recommended to ensure the most appropriate dental implant treatment approach.

Bone formation at porous titanium implants coated with multiple layers of recombinant human bone morphogenetic protein-2 cDNA plasmid in the posterior mandible in dogs.

PURPOSE: The objective of this study was to evaluate peri-implant bone formation and osseointegration at titanium implants coated with multiple layers of recombinant human bone morphogenetic protein-2 (rhBMP-2) cDNA placed into canine mandibles. MATERIALS AND METHODS: The rhBMP-2 plasmid was assembled on sandblasted/dual-acid-etched pure titanium implant surfaces using layer-by-layer assembly. The rhBMP-2 plasmid-coated implants were placed into the edentulous posterior mandibles of 12 adult beagle dogs. Implants without the rhBMP-2 plasmid coating served as controls. Treatments were randomized between jaw quadrants, and four implants were placed in each mandibular quadrant. After 4, 8, and 12 weeks in situ, mandibles were retrieved and prepared for removal torque testing and histomorphometric evaluation. RESULTS: Eight layers of rhBMP-2 plasmid were assembled onto the implant surfaces. Histomorphometric analysis showed that, after 4 and 8 weeks of healing, the intrathread bone area (BA) was slightly higher for test implants (54.21% and 59.56%) than for control implants (38.48% and 54.98%), respectively, but no statistically significant differences were seen at any time points. Mechanical tests showed that the mean removal torque values of the rhBMP-2 cDNA-coated implants were greater than those of the control implants after 8 weeks of healing (91 Ncm versus 61 Ncm; P = .31). CONCLUSION: Coating implants with multiple layers of an rhBMP-2 plasmid did not promote peri-implant bone formation and osseointegration in this model.

Effects of zinc-substituted nano-hydroxyapatite coatings on bone integration with implant surfaces.

OBJECTIVE: The purpose of this study was to investigate the effects of a zinc-substituted nano-hydroxyapatite (Zn-HA) coating, applied by an electrochemical process, on implant osseointegraton in a rabbit model. METHODS: A Zn-HA coating or an HA coating was deposited using an electrochemical process. Surface morphology was examined using field-emission scanning electron microscopy. The crystal structure and chemical composition of the coatings were examined using an X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR). A total of 78 implants were inserted into femurs and tibias of rabbits. After two, four, and eight weeks, femurs and tibias were retrieved and prepared for histomorphometric evaluation and removal torque (RTQ) tests. RESULTS: Rod-like HA crystals appeared on both implant surfaces. The dimensions of the Zn-HA crystals seemed to be smaller than those of HA. XRD patterns showed that the peaks of both coatings matched well with standard HA patterns. FTIR spectra showed that both coatings consisted of HA crystals. The Zn-HA coating significantly improved the bone area within all threads after four and eight weeks (P<0.05), the bone to implant contact (BIC) at four weeks (P<0.05), and RTQ values after four and eight weeks (P<0.05). CONCLUSIONS: The study showed that an electrochemically deposited Zn-HA coating has potential for improving bone integration with an implant surface.