Comparing Operators and Imaging Techniques When Performing Trans-Crestal Sinus Augmentation: A Pilot Study.

The aim of this article was to compare baseline residual ridge height using Cone-beam Computed Tomography (CBCT) and panoramic radiographs. A secondary aim was to examine the magnitude of vertical bone gain 6 months after trans-crestal sinus augmentation and compare it between operators. Thirty patients, who underwent trans-crestal sinus augmentation simultaneously with dental implant placement, were included in this retrospective analysis. Surgeries were done by 2 experienced surgeons (EM and EG) using the same surgical protocol and materials. Preoperative residual ridge height was measured on panoramic and CBCT images. The final bone height and the magnitude of the vertical augmentation were measured on panoramic X ray taken 6 months after surgery. Mean residual ridge height measured preoperatively using CBCT was 6.07 ± 1.38 mm, whereas these same measurements on the panoramic radiographs yielded similar results (6.08 ± 1.43 mm), which were statistically insignificant (P = .535). Postoperative healing was uneventful in all cases. All 30 implants were successfully osseointegrated at 6 months. The mean overall final bone height was 12.87 ± 1.39 mm (12.61 ± 1.21 and 13.39 ± 1.63 mm for operators EM and EG, respectively; P = .19). Likewise, mean postoperative bone height gain was 6.78 ± 1.57 mm, which was 6.68 ± 1.32 and 6.99 ± 2.06 mm for operators EM and EG, respectively (P = .66). A moderate positive correlation was found between residual bone height and final bone height (r = 0.43, P = .002). A moderate negative correlation was found between residual bone height and augmented bone height (r = -0.53, P = .002). Sinus augmentation performed trans-crestally produce consistent results with minimal interoperator differences between experienced clinicians. Both CBCT and panoramic radiographs produced similar assessment of the preoperative residual bone height.

Palatal soft tissue thickness around dental implants and natural teeth in health and disease: A cross sectional study.

BACKGROUND: Previous studies focused on the influence of buccal mucosa thickness on peri-implant bone loss and inflammation, with inconclusive results. We observed substantially thicker palatal mucosal tissues at peri-implantitis sites. Therefore, we hypothesize that thick palatal peri-implant mucosa may be associated with deeper pockets and disease severity. PURPOSE: To compare the thickness of the palatal tissue between natural teeth and implants in periodontal health and disease. METHODS: Adult, non-smoker, healthy patients who visited our department for periodontal examination or treatment with restored implants in the posterior maxilla were recruited. Probing depth (PD), plaque index (PI), gingival index (GI) and radiographic measurements were recorded around implant and the contralateral tooth. Palatal tissue thickness was measured using a 30G needle that was inserted perpendicular into the mucosa at the bottom of the periodontal/peri-implant pocket and 3 mm coronally. Differences in the palatal tissue thickness between teeth and implants (in the same patient) was performed using t-test; as well as between peri-implantitis and non-peri-implantitis sites (among patients). RESULTS: Sixty patients were included. Thirty-four implants were diagnosed with peri-implantitis and 26 healthy/mucositis implants with corresponding 24 healthy/gingivitis teeth and 36 teeth with attachment loss. Mean PD was higher around implants (4.47 ± 1.57 mm) than teeth (3.61 ± 1.23 mm, p = 0.001). The thickness of implants' palatal mucosa was higher than in teeth, at the base of the pocket and 3 mm coronally (4.58 ± 1.38 mm vs. 3.01 ± 1.11, p = 0.000; 3.58 ± 2.15 vs. 1.89 ± 1.11, p = 0.000, respectively). Mean palatal tissue thickness was 4.32 ± 2.35 mm for the peri-implantitis group while only 2.61 ± 1.39 in healthy implants, 3 mm coronal to the base of the pocket (p = 0.001). Palatal thickness at peri-implantitis sites was higher (4.32 ± 2.35) compared to periodontitis sites (2.23 ± 0.93), p = 0.000. Implant sites with palatal mucosa >4 mm (n = 32) had deeper mean pockets (5.58 ± 1.98) compared with thinner (≤4 mm) sites (n = 28) (4.48 ± 1.18, p = 0.018). CONCLUSION: Thicker palatal tissue around implants is associated with deeper palatal pockets. Thick palatal tissue was found around implants diagnosed with peri-implantitis.

Histological and dimensional changes of the alveolar ridge following tooth extraction when using collagen matrix and collagen-embedded xenogenic bone substitute: A randomized clinical trial.

AIM: To assess the horizontal and vertical dimensional changes of the alveolar ridge when using a collagen matrix in combination with collagen embedded xenogenic bone substitute, in comparison with natural healing after tooth extraction. METHODS: Patients that required extraction in non-molars areas were included. Test group-15 sockets were treated with deproteinized bovine bone mineral containing 10% collagen (DBBM-C), covered by a procaine collagen membrane (CMXs). Control group-15 sockets left for spontaneous healing. We used a custom-made acrylic stent as a reference for alveolar ridge measurements. Six-month postoperative, a single implant was placed in the experimental site. A core biopsy was taken from the site, using a trephine bur. Histomorphometric analysis assessed bone area, connective tissue, bone marrow, and residual bone graft. RESULTS: Six months later, horizontal ridge width at -3 mm showed a significant (p < 0.05) reduction in both groups albeit smaller in the test group 1.19 ± 1.55 mm, compared with the control 2.27 ± 1.52 (p = 0.087). At -5 mm sub-crestally, statistically non-significant reduction was noted in both groups, 1.61 ± 1.53 and 1.96 ± 1.52 mm for the test and control groups, respectively (p = 0.542). Vertical changes were smaller in the test group (0.14 ± 1.84 mm) compared with control (0.98 ± 1.49 mm). Keratinized tissue (KT) width was 7.3 ± 2.13 and 7.5 ± 3.49 mm in the test and control groups, respectively. Newly formed bone occupied 33.79 ± 17.37% and 51.14 ± 23.04% in the test and control groups, respectively, (p = 0.11). Connective tissue volume was 33.74 ± 13.81% and 30.12 ± 18.32% in the test and control groups, respectively (p = 0.65). Bone marrow occupied 19.57 ± 10.26% and 18.74 ± 17.15% in the test and control groups, respectively (p = 0.91). Residual graft occupied 12.9 ± 9.88% in the test group. CONCLUSION: Alveolar ridge preservation using DBBM-C resulted in reductions of the vertical and horizontal dimensions albeit not reaching statistical significance. The larger than anticipated standard deviation and smaller inter-group differences might account for this phenomenon.

Volumetric assessment of changes in the alveolar ridge dimension following guided bone regeneration using a combination freeze-dried bone allograft with collagen membrane or novel resorbable scaffold: A prospective two-center clinical trial.

BACKGROUND: The aim of this study was to examine osseous changes following lateral bone augmentation using a novel scaffold (OV) alone and compare it to combination therapy using freeze-dried bone allograft (FDBA) and resorbable collagen membrane (FDBA/CM). METHODS: Thirty patients completed this 9-months prospective two-center cohort clinical trial. Before surgery and 9-months re-entry, linear measurements were performed, and impressions taken. Cone-beam computed tomography (CBCT) were done at baseline and 9 months. DICOM slice data were converted into volumetric images using 3D Slicer. Following 3D volumetric image construction, pre- and post-op Standard Triangle Language files were superimposed and volumetric data were extracted for a 10-mm region of interest. Linear measurements were compared similarly. RESULTS: Baseline clinical parameters were similar in both groups (4.22 and 4.53 mm for OV and FDBA/CM at -2 mm, respectively). Following treatment, vertical distance from the stent had changed minimally (-0.36 and -0.12 mm, respectively). Similarly, lateral bone gain ranged from 0 to 0.4 mm, for both groups. To the contrary, the CBCT measurements showed a significantly greater increase in horizontal width in the control at -2 mm (0.95 ± 0.2 mm) compared with -0.62 mm for the OV (P = 0.000). Similar changes were observed at -5 mm (0.63 and -0.41 mm, respectively, P = 0.01). Sites volume had increased from 266 ± 149 mm3 to 360 ± 138 mm3 (P = 0.001) for FDBA/CM with negligible changes for OV (from 334 to 335 mm3 , P = 0.952). these between-group changes being statistically significant (P = 0.023). CONCLUSION: FDBA/CM yielded better albeit moderate increase in the volume of the edentulous ridge, while OV scaffolds failed to produce similar results.

Severe Complications Following Maxillary Sinus Augmentation Using Poly L-lactide-co-ε-caprolactone-Coated Bovine Bone: A Retrospective Study.

PURPOSE: To describe the postoperative complications following lateral wall sinus augmentation using (poly L-lactideco-ε-caprolactone; PLCL) and natural polysaccharides polymers-coated bovine bone (PBB). The secondary aims were to examine histologic findings and to propose complication management alternatives. MATERIALS AND METHODS: This retrospective study included 61 subjects who underwent 67 lateral wall sinus augmentation procedures using PBB in the standard protocol. In cases that presented complications, treatment included additional antibiotic therapy, implant removal, or sinus reentry and total removal of the grafting material. In three cases, biopsy specimens were taken from the sinuses, and histologic analyses were performed. RESULTS: The prevalence of postoperative complications was 32.8% (22 of 67 cases) in 18 of the patients (29.5%). The most prevalent symptoms were persistent pain (68.2%), swelling (63.6%), and oroantral fistula (54.5%). Radiographic signs appeared in 45.5% of the complications. A total of 24 implants failed; thus, an overall 80.3% survival rate was established at 19 months. The vast majority of complications (86.4%) were treated eventually with reentry surgery and revealed that the sinus was full with granulation tissue surrounding pieces of a nonossified rubber-like material. In cases where implants were placed, nonosseointegrated implants were surrounded by soft tissue. The sinus was cleaned thoroughly; the graft material remnants were removed together with inflamed parts of the sinus membrane, followed by chlorhexidine and saline lavages. In the biopsy specimens taken from the sinus cavity, there were no histologic features of new bone formation around the grafted material. CONCLUSION: Lateral wall maxillary sinus augmentation using PBB was associated with an acute sinus infection histologic appearance and with a 7-times-higher failure rate compared with previous reports. This serious adverse event suggests that PBB cannot be recommended for maxillary sinus augmentations.

The effect of a surgeon's position on the axial inclination of dental implants placed freehand: a single-blind study.

OBJECTIVES: To examine whether a surgeons' position affects the axial angulation of dental implants placed freehand. METHOD AND MATERIALS: Implants' axial angulation was assessed on digital panoramic radiographs. An occlusal line was plotted based on the neighboring teeth/crowns. The mesial angle between the long axis of the implant and the occlusal line was measured. In addition, post-hoc ideal implant-positioning planning was done on the panoramic digital image, and the angle of the intersection between the long axis of the actual and post-hoc ideal implant was measured. Student t test for unpaired observations and the Kolmogorov-Smirnov nonparametric tests were utilized to compare the ipsi- and contralateral sides and between clinicians. RESULTS: Seventy-seven patients (149 implants) were eligible for the study. Implants had slight mesial inclination (mean 97.7 ± 8.7 degrees) which was similar for both the ipsi- (98.2 ± 8.4 degrees) and contralateral sides (97.2 ± 9.1 degrees), P = .491. For the post-hoc planning versus actual placement comparison, the overall median (interquartile range) of implant angular deviation was minimal (-0.25 degrees [-2.98, +3.47]). This was true for both the ipsilateral (-0.5 degrees [-2.9, +2.9]) and contralateral (-0.2 [-4.2, +5.4]) sides, P = .55. For the actual versus post-hoc planning, most observations clustered around the midline (zero to minimal deviation), while for the implant to occlusal plane angle, a tendency towards slight mesial angulation was observed. CONCLUSIONS: Dental implants placed freehand by experienced clinicians have only slight axial deviation as measured from post-hoc optimal position. Implants placed in ipsilateral and contralateral sides and by left- and right-dominant-hand clinicians had similar angulations.

Ridge preservation procedures revisited: A randomized controlled trial to evaluate dimensional changes with two different surgical protocols.

BACKGROUND: The effect of different surgical techniques for ridge preservation on soft tissue parameters has seldom been investigated. The objective of this study was to compare the effect of two different ridge preservation techniques on soft and hard tissue dimensions. METHODS: Thirty patients requiring tooth extraction were randomly allocated to either control group C (allograft covered with a non-crosslinked collagen membrane with primary closure) or experimental group E (allograft covered with cross-linked collagen membrane left exposed). Sites were surgically re-entered at 6 months. Soft and hard tissue measurements, cone beam computed tomography (CBCT), and cast measurements were taken at baseline and 6 months. RESULTS: Twenty-eight patients were included in this analysis. When the two treatment groups were compared, the width of the buccal keratinized tissue in the E group showed an increase of 0.43 ± 0.42 mm compared to net loss of 1.57 ± 0.51 mm for the C (P = 0.006). Similarly, buccal tissue thickness has increased in the E group 0.46 ± 0.22 mm compared to a loss of 0.15 ± 0.23 mm in the C group (P = 0.068). Volumetric assessment of the changes in the alveolar ridge for the E group showed a slight decrease (68.3 ± 17 mm3) whereas the C group has experienced almost double this loss (107.5 ± 11 mm3; P = 0.07). Crestal width, measured on the CBCT scan, has shown significant reduction in the C group (4.18 ± 0.56 mm) compared to only 1.74 ± 0.4 mm in the E group (P = 0.003). CONCLUSION: Crosslinked collagen membrane with allograft placed intentionally non-submerged resulted in better preservation of the keratinized tissues (width and thickness) with similar and at times better osseous preservation following extraction.

Biocompatibility and osteoconductivity of PLCL coated and noncoated xenografts: An in vitro and preclinical trial.

BACKGROUND: Cells, scaffolds, and growth factors are the key components in bone tissue engineering. Scaffold composition, topography, and architecture influence the amount of regenerated bone in the implantation site. The aims of the study were to compare viability and proliferation of mesenchymal stem cells (MSCs) seeded onto two commercial xenografts: Bio-Oss (BO) and bioactive bone bovine (BB). Next, these materials were compared for histomorphometric bone formation in a socket preservation model in rats. MATERIALS AND METHODS: MSCs were seeded onto monolayers of BO or BB granules. Cell viability and proliferation were evaluated after incubation of 0, 2, 20, and 48 h. A total of 24 Sprague Dawley rats underwent unilateral extraction of maxillary molars. Rats were randomly divided into three groups: natural healing (nongrafted socket) or socket preservation with either BO or BB. Rats were sacrificed after 8 weeks, and histomorphometric analysis was done to evaluate bone formation and residual scaffold at the extraction site. RESULTS: Differences in the metabolic activity of MSCs that were seeded onto BO or BB was observed at 2 h after seeding: the metabolic activity was elevated compared to baseline in the BB (P = .046) and not changed in the BO wells (P = .84). After 20 h, the metabolic activity of MSCs seeded onto BO was decreasing (P = .005), while cell viability was not changed in the BB group (P = .356). Intergroup comparison revealed higher metabolic activity of MSCs seeded on BB after 48 h compared with BO (P = .016). The in vivo results demonstrated differences in socket healing between the groups: percentage of new bone was higher in the BB compared to BO group (39.1 ± 14.3 vs. 23.7 ± 10.8%, respectively, P = .096). Connective tissue portion was higher in the BO group compared with BB (73.7 ± 11.1 vs. 49.6 ± 13.7%, respectively, P = .018). Residual grafting martial was higher in the BB (11.34 ± 4.18 vs. 2.62 ± 1.23%, P = .011). CONCLUSIONS: The results of this study demonstrating higher vitality and proliferation of MSCs seeded onto BB. Furthermore, following ridge preservation, higher percentage of new bone and lower residual scaffold were found in the BB compared with BO. This enhanced regenerative response might be the result of an enhancement of metabolic activity in cells attached to it. Further research will be needed to understand the precise mechanism.

Safety profile and long-term engraftment of human CD31+ blood progenitors in bone tissue engineering.

BACKGROUND: Endothelial progenitor cells (EPCs) participate in angiogenesis and induce favorable micro-environments for tissue regeneration. The efficacy of EPCs in regenerative medicine is extensively studied; however, their safety profile remains unknown. Therefore, our aims were to evaluate the safety profile of human peripheral blood-derived EPCs (hEPCs) and to assess the long-term efficacy of hEPCs in bone tissue engineering. METHODS: hEPCs were isolated from peripheral blood, cultured and characterized. ß tricalcium phosphate scaffold (ßTCP, control) or 106 hEPCs loaded onto ßTCP were transplanted in a nude rat calvaria model. New bone formation and blood vessel density were analyzed using histomorphometry and micro-computed tomography (CT). Safety of hEPCs using karyotype analysis, tumorigenecity and biodistribution to target organs was evaluated. RESULTS: On the cellular level, hEPCs retained their karyotype during cell expansion (seven passages). Five months following local hEPC transplantation, on the tissue and organ level, no inflammatory reaction or dysplastic change was evident at the transplanted site or in distant organs. Direct engraftment was evident as CD31 human antigens were detected lining vessel walls in the transplanted site. In distant organs human antigens were absent, negating biodistribution. Bone area fraction and bone height were doubled by hEPC transplantation without affecting mineral density and bone architecture. Additionally, local transplantation of hEPCs increased blood vessel density by nine-fold. CONCLUSIONS: Local transplantation of hEPCs showed a positive safety profile. Furthermore, enhanced angiogenesis and osteogenesis without mineral density change was found. These results bring us one step closer to first-in-human trials using hEPCs for bone regeneration.

VEGF release from a polymeric nanofiber scaffold for improved angiogenesis.

Angiogenesis plays a pivotal role in tissue engineering and regenerative medicine. This study aimed to develop an electrospun fiber scaffold that supports release of recombinant human vascular endothelial growth factor (rhVEGF) to enhance angiogenesis. Scaffolds composed of core-shell fibers were fabricated using co-electrospinning. The core solution was composed of polyethylene oxide and mixed with rhVEGF. The shell solution was composed of polycarpolactone, with 0.25, 1, and 3% of polyethylene glycol (PEG) to manipulate pore size on the shell. Pore size and density increased with higher PEG concentrations. Similarly, rhVEGF release was affected by PEG concentration: initial burst release was found in all scaffolds, followed by continuous 4 h release in 3% PEG and 18 h release in the 0.25 and 1% PEG polymeric scaffolds. Endothelial cell migration toward rhVEGF-incorporated polymeric scaffold was 80-fold higher as compared to VEGF-free polymeric scaffold. In a subcutaneous mouse model, VEGF-incorporated polymeric scaffold stimulated cell migration into the scaffold within three days and significantly enhanced blood vessels formation within 14 days, whereas control scaffolds contained few vessels. In conclusion, the described novel scaffold represents a promising device for vascular tissue engineering, which may be of clinical significance in treating vascular deficient wounds. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2712-2721, 2017.

Clinical accuracy of a novel open-lattice-frame implant positioning system: A case series.

OBJECTIVE: The purpose of the study was to assess the clinical accuracy of a novel open-lattice-frame implant positioning system by evaluating the deviation between planned and actual implant positions on pre- and postoperative cone beam computed tomography (CBCT) images of patients treated with dental implants. Secondary aims were to record surgical time from first incision to end of implant surgery and start of suturing, and to record patient and surgeon satisfaction from the implant surgical procedure. Pre- and postoperative CBCT of 10 patients receiving 18 dental implants were used to generate implant angular deviations and implant shoulder and apex deviations. Mean angular deviation was 2.96 ±â€¯1.31 degrees (range 0.75 to 5.60 degrees). Mean shoulder and apex deviations were 1.07 ±â€¯0.49 mm (range 0.38 to 1.85 mm) and 1.35 ±â€¯0.57 mm (range 0.52 to 2.19 mm), respectively. Mean time from first incision to start of suturing was 24 ±â€¯7 minutes. Patient satisfaction ranged between 8 and 10, and surgeon satisfaction regarding the procedure ranged between 9 and 10, on a scale of 1 to 10. The open-lattice-frame implant positioning system provided adequate accuracy, and may aid in improving patient-related and surgeon-related outcomes by improving surgical accuracy and shortening surgical treatment duration.

Ridge Preservation Using Composite Alloplastic Materials: A Randomized Control Clinical and Histological Study in Humans.

AIM: To evaluate (clinically, histologically, and histo-morphometrically) the use of composite materials (Biphasic calcium sulphate [BCS] with ß Tri-Calcium Phosphate (ß-TCP) and Hydroxyapatite [HA]) in extraction socket sites and compare it to un-disturbed natural healing. MATERIAL AND METHODS: Prospective clinical trial of 36 patients (40 extraction sockets) were randomly assigned to either test or control group. Alveolar ridge horizontal dimension was measured in the middle of the socket at crest and 3 and 6 mm subcrestally. Crestal vertical height was measured at baseline surgery and at 4 month re-entry, at which time bone core biopsies were harvested from the center of the edentulous ridge. Histo-morphometric evaluation of the samples was performed using hematoxylin & eosin stains and morphometric software. RESULTS: The change in horizontal ridge width was higher in the control compared to the experimental group: 2.28 ± 2.36 mm versus 0.03 ± 2.32 mm (p = .007) at -3 mm and 2.28 ± 2.43 versus 0.035 ± 3.05 (p = .02) at -6 mm, for the experimental and control sites, respectively. The vertical distance form bone crest to neighboring horizontal line interconnecting the neighboring teeth was minimal in both groups (0.307 ± 2.01 mm versus 0.14 ± 2.03 mm [p = 0.41]). Residual scaffolds occupied 15.99 ± 11.4% of the volume in the grafted (test) sites while bone area fraction was not statistically different among the groups (47.7 ± 10.6% versus 52.6 ± 11.6%, test versus control, respectively p = .39). The percentage of connective tissue in the control group was significantly higher that test group (36.3 ± 19.4% versus 46.7 ± 10.6% test versus control, respectively, p = .013). CONCLUSION: Ridge preservation technique using a combination of two synthetic bone grafts ß-TCP and HA with BCS resulted in greater stability in the horizontal dimension after 4 months.

Dimensional Changes Following Lateral Wall Sinus Augmentation Without Concomitant Implant Placement Using a Composite Bone Graft.

PURPOSE: To evaluate changes in sinus dimensions immediately postoperatively and 1 year later using a composite of bovine-derived xenograft and autogenous bone for lateral bone augmentation of the maxillary sinus. MATERIALS AND METHODS: Patients who underwent lateral wall sinus augmentation procedures without concomitant implant placement were considered for this retrospective analysis if they had three consecutive panoramic radiographs: pretreatment (T0), immediately after lateral wall sinus augmentation (T1), and approximately 1 year postoperatively (T2). Eighteen subjects aged 47 to 69 years were included. The surgical protocol included grafting with a composite of bovine-derived xenograft and autogenous bone (9:1 ratio). Digital panoramic radiographs were transferred into measurement software, and the following measurements were performed: (1) vertical distance from the alveolar crest to the height of the augmented material, (2) sagittal area of the grafted area, and (3) vertical distance from the alveolar crest to the roof of the maxillary sinus. All measurements were performed by one examiner. Double measurements were performed in nine patients at T2, and the calculated Cronbach's alpha statistic was very high (.9658 to .9882). RESULTS: The mean overall sinus sagittal area was 1,330 ± 481 mm2 prior to the grafting procedure, when it decreased to 858.2 ± 436 mm2 (range, 380.7 to 2,134 mm2) immediately postoperatively (P = .0035) and remained stable at 1 year (mean, 882.2 ± 384 mm2, P > .05). Similarly, the overall area of the grafted material at the time of surgery was 468.3 ± 208 mm2 and was only slightly reduced at 1 year (422.2 ± 193 mm2). The midsagittal graft height at T1 (mean, 20.67 ± 4.5 mm) was insignificantly and minimally reduced at 1 year (mean, 19.35 ± 4.9 mm). CONCLUSION: The linear dimensions of composite bone-derived xenograft/autogenous bone grafts following lateral wall sinus augmentation exhibited minimal changes during the 8- to 12-month healing period.

Intraoperative Measurement of the Distance from the Bottom of Osteotomy to the Mandibular Canal Using a Novel Ultrasonic Device.

BACKGROUND: In our previous study, we found that a novel ultrasound (US) device may serve as a useful intraoperative tool to measure the distance from osteotomy to the inferior alveolar canal (IAC). PURPOSE: To validate our previous results in a larger group of osteotomies in the posterior mandible. METHODS: During dental implant placement surgery, osteotomies were created using a standardized 2-mm-diameter pilot drill. The distance from the bottom of the osteotome to the IAC was assessed using an ultrasonic device and compared with a standard panoramic radiograph used to measure the same residual distance. The total distance from the crestal bone to the IAC was measured on a preoperative computed tomography (CT) and compared with total US measurements by summing the drill depth with residual depth measurements. RESULTS: Mean radiographic and US residual distances were 5.19 ± 1.95 mm, 5.01 ± 1.82 mm, p = 0.79 respectively. These measurements presented strong positive correlations (r = 0.61, p = .01). Mean total CT distance was 13.48 ± 2.66 mm; mean total US calculation was 13.69 ± 2.51 mm. No significant difference was found (p > .05). CONCLUSIONS: The results support our previous pilot study and confirm that the tested US device identifies the IAC and measures the distance from the osteotomy to the roof of the mandibular canal.

Periodontal Conditions and Tumor Necrosis Factor-Alpha Level in Gingival Crevicular Fluid of Scleroderma Patients.

BACKGROUND: Systemic sclerosis (SSc) is a chronic disease with prominent vasculopathy, inflammation, production of autoantibodies, and tissue fibrosis. Periodontitis is a chronic inflammatory oral condition manifesting as microbial infection, inflammation and destruction of the alveolar bone. In both conditions tumor necrosis factor-alpha (TNFα) and other proinflammatory cytokines play an important role in pathogenesis. OBJECTIVES: To assess the periodontal status in SSc patients and compare these parameters to TNFα level in gingival crevicular fluid (GCF) of SSc patients and healthy controls. METHODS: Twenty SSc patients and 20 controls underwent periodontal examination, including probing depth (PD), plaque index (PI), gingival-index (GI), bleeding on probing (BOP), and measurement of TNFα levels in collected GCF. RESULTS: SSc patients had a greater PD (3.74 ± 0.32 mm vs. 3.35 ± 0.31 mm, P > 0.003), GI (1.53 ± 0.34 vs. 1.12 ± 0.54, P > 0.049), and non-significantly higher BOP than controls. TNFα levels in GCF were higher in SSc patients (1.63 ± 0.36 vs. 1.15 ± 0.34 pg/ml, P = 0.001). Periodontitis parameters correlated with several SSc variables; PI in particular was higher in patients with longer disease duration, sclerodactyly, more severe skin involvement, and SSc activity score. CONCLUSIONS: Patients with SSc have higher indices of periodontal inflammation and higher TNFα level in GCF than did healthy individuals. These changes probably reflect the complexity of factors that influence oral health in SSc. Common pathologic pathways may be responsible for the association between SSc and periodontitis, which requires further study.

Soft and Hard Tissue Changes around Tissue-Oriented Tulip-Design Implant Abutments: A 1-Year Randomized Prospective Clinical Trial.

BACKGROUND: The advantages of platform switching using narrower abutments remain controversial. Many researchers suggest that platform switching can yield enhanced clinical results, while others remain skeptical. We hypothesize that the effectiveness of platform switching might be associated with the degree of reduction in size of the abutment. PURPOSE: To radiographically and clinically examine a new abutment design created to move the implant-abutment interface farther medially. MATERIALS AND METHODS: This was a prospective, randomized controlled clinical trial that included 27 patients (41 MIS Lance Plus® implants; MIS Implant Technologies, Karmiel, Israel). The patients' age ranged from 39 to 75 years. At the second stage of the surgery, the implants were randomly assigned to either the new platform switch Tulip abutment (TA) design or to the standard platform abutment (SA). Implant probing depth (IPD) and bleeding on probing (BOP) were recorded at baseline and after 12 months. Standardized periapical radiographs were taken (at baseline and at 12 months) and the marginal bone height measured. RESULTS: All implants were successfully integrated. The mean IPD at 1 year post-op was 2.91 mm for the SA group and 2.69 mm for the TA group (p > .05). Similarly, the BOP at 1 year was almost identical in both groups. The mean values of bone resorption at baseline were 0.98 ± 0.37 mm and 0.69 ± 0.20 for the TA and SA groups, respectively (p > .05). Bone loss (baseline to 12 months) was significantly greater in the SA group compared with the TA group. CONCLUSIONS: Use of the new TA, with its significantly downsized diameter, resulted in reduced bone loss at 1 year. Further research will be required to assess the long-term effect of this abutment on peri-implant health.

Human blood-derived endothelial progenitor cells augment vasculogenesis and osteogenesis.

INTRODUCTION: Endothelial progenitor cells (EPC) participate in angiogenesis and osteogenesis, therefore, have the potential to enhance extra-cortical bone formation. AIM: To enhance extra-cortical bone formation following local transplantation of human peripheral blood-derived EPC (hEPC) in a guided bone regeneration (GBR) nude rat calvaria model. MATERIALS AND METHODS: hEPC were isolated from peripheral blood of healthy volunteers. Cells were cultured and characterized by flow cytometry for specific endothelial markers. Following exposure of nude rat calvaria, gold domes were filled with 10(6) hEPC mixed with ßTCP (n = 6). Domes filled with ßTCP served as control (n = 6). Rats were sacrificed after 3 months. New bone formation and blood vessel density were analysed by histology and histomorphometry. Transplanted hEPC were located in the regenerated tissue using immunohistology. RESULTS: Abundant vasculature was observed adjacent to the newly formed bone. According to histomorphometric analysis: blood vessel density was 7.5 folds higher in the hEPC compared with the control group. Similarly, gained extra-cortical bone height (2.46 ± 1.1 mm versus 0.843 ± 0.61 mm, p = 0.01) and bone area fraction (19.42 ± 7.48% versus 4.81 ± 3.93%, p = 0.001) were elevated following hEPC transplantation. Moreover, hEPC expressing human-specific CD31 were integrated into blood vessel walls adjacent to newly formed bone. CONCLUSION: In nude rat GBR calvaria model, transplantation of hEPC significantly enhanced vasculogenesis and osteogenesis.

Co-transplantation of endothelial progenitor cells and mesenchymal stem cells promote neovascularization and bone regeneration.

BACKGROUND: Bone formation relies on sufficient blood supply and osteoprogenitor cells. PURPOSE: The study aims to evaluate the influence of endothelial progenitor cells (EPCs) in combination with mesenchymal stem cells (MSCs) on early vascularization and intramembranous bone regeneration. MATERIALS AND METHODS: Vertical bone regeneration was tested in rat calvarium guided bone regeneration model. Gold domes were filled with a mixture of 5 × 10(5) osteogenic transformed MSC and 5 × 10(5) EPC (EPC/MSC) that were mixed with ß-tricalcium phosphate (ßTCP) scaffold. Domes filled with ßTCP alone served as control. Rats were sacrificed after 4 or 12 weeks. Histomorphometry was used to determine blood vessel (Bv) density, vertical bone height, and bone area in the regenerated tissue. RESULTS: At both time points, new augmented hard tissue filled the space under the dome, and Bv density was higher in the EPC/MSC transplanted group vs control. However, bone height and bone area were similar among the groups 4 weeks posttransplantation, but were doubled in the EPC/MSC transplanted group 12 weeks posttransplantation. CONCLUSIONS: EPC/MSC transplantation increases Bv formation in the early stages of healing that precedes enhancement of extracortical bone regeneration in later stages.

Peripheral blood-derived endothelial progenitor cells enhance vertical bone formation.

BACKGROUND: This study presents a novel cell-based approach for extra-cortical bone regeneration. OBJECTIVE: To enhance vertical bone formation by combining guided bone regeneration and transplantation of peripheral blood-derived endothelial progenitor cells (EPCs) in a rat calvaria model. MATERIALS AND METHODS: EPCs were isolated from peripheral blood of inbred rats. Gold domes (7 mm radius, 5 mm height) were filled with ß-tricalcium phosphate (ßTCP) mixed with 5 × 10(5) EPC. Domes filled with ßTCP served as control (CNT). Rats were sacrificed after 3 months. Vertical bone augmentation was analyzed using histology, histomorphometry, and microcomputed tomography (µCT). RESULTS: In all rats, hard tissue filled the space under the dome. Histomorphometric analysis revealed that EPC transplantations doubled vertical bone height (EPC 4.04 ± 0.22 mm vs CNT 2.29 ± 0.22 mm, p ≤ .001). EPC also caused ∼50% increase in bone area fraction (EPC 47.3 ± 3.1% vs CNT 31.1 ± 2.7%, p ≤ .003). µCT results also showed that bone volume fraction (BV/TV) was higher in EPC group (p = .0169). In both groups, BV/TV declined from the bottom to the top of the samples. No differences in tissue mineral density were found between EPC and CNT groups. CONCLUSION: EPC transplantation significantly improved bone formation especially in the areas that are remote from the original bone.