Allogeneic Dentin Graft: A Review on Its Osteoinductivity and Antigenicity.

Studies on allogeneic demineralized dentin matrix (Allo-DDM) implantation in the 1960s and 1970s provided the most reliable preclinical evidence of bone formation and antigenicity in an extraosseous site. Recently, applications of Allo-DDM at skeletal sites were studied, and have provided reliable evidence of bone-forming capacity and negligible antigenicity. However, the osteoinductivity and antigenicity properties of Allo-DDM in extraskeletal sites have not yet been investigated due to the lack of follow-up studies after the initial research. The clinical applications of autogenous DDM (Auto-DDM) have been standardized in some countries. Long-term clinical studies have reported the development of several shapes of Auto-DDM, such as powders, blocks, moldable forms, and composites, with recombinant human bone morphogenetic protein-2. For the development of Allo-DDM as a reliable bone graft substitute next to Auto-DDM, we reviewed preclinical studies on the bone induction capacity of allogeneic dentin at extraskeletal as well as skeletal sites. Electronic databases were screened for this review in January 2020 and searched from 1960 to 2019. This review aims to provide a foundation on the preclinical studies of Allo-DDM, which could enable future researches on its osteogenic capability and antigenicity. In conclusion, Allo-DDM showed great potential for osteoinductivity in extraskeletal sites with low antigenicity, which neither adversely affected osteogenic capability nor provoked immunologic reactions. However, the risk of viral disease transmission should be researched before the clinical application of Allo-DDM.

Three-Dimensional Volumetric Analysis of Multiple Gingival Recession Defects Treated by the Vestibular Incision Subperiosteal Tunnel Access (VISTA) Procedure.

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Maxillary Sinus Floor and Alveolar Crest Alterations Following Extraction of Single Maxillary Molars: A Retrospective CBCT Analysis.

This retrospective study investigated the changes in the maxillary sinus floor and alveolar crest following extraction of maxillary molars. Pre- and postextraction cone beam computed tomography scans of 23 patients were analyzed. Paired-sample t tests compared pre- and postextraction measurements, and independent-sample t tests were utilized for intergroup comparisons. Pearson correlation was used to assess the association between the measured variables and the outcome measures. The mean alveolar bone height reduction was 3.42 ± 2.40 mm and the alveolar crest loss was 3.07 ± 2.53 mm. The maxillary sinus floor position shifted coronally by a mean of 0.47 ± 0.32 mm. Approximately 88% of postextraction changes in alveolar bone height were due to alveolar crest changes, compared to 12% due to changes in the sinus floor position. The results of this study challenge the commonly held concept of extensive postextraction maxillary sinus floor alterations leading to sinus pneumatization.

Retrospective Analysis of the Outcome of Ridge Preservation with Anorganic Bovine Bone Mineral: Marginal Bone Level at Implants Placed Following Healing of Grafted Extraction Sockets.

The objective of this study was to investigate marginal bone level (MBL) changes as the primary outcome of implants placed following healing of extraction sockets treated with ridge preservation, compared to implants placed following unassisted healing. A total of 268 patients (contributing 572 implants) treated from April 2005 to March 2013 were included in this retrospective study. Following estimation of the overall success rate of implants placed in the practice, 129 patients (contributing 222 implants) met the inclusion and exclusion criteria to be further evaluated. Of these, 78 patients (contributing 105 implants) received ridge preservation procedures, which entailed placement of anorganic bovine bone mineral covered with polytetrafluoroethylene membrane. The other 51 patients (contributing 117 implants), with healed sites without history of bone grafting, served as controls. Digital radiographs were taken at the time of implant placement and during follow-up visits. The mean follow-up period for ridge preservation sites was 33.6 months (range: 7.5 to 61.5 months) and for healed sites was 36.3 months (range: 6 to 91.2 months). The survival rate of implants in sites following healing of ridge preservation was 97.3%, compared to 98.5% in the nongrafted healed sites. The mean MBL changes during the observation period were 0.11 and 0.07 mm on the mesial and 0.06 and 0.06 mm on the distal aspects of the ridge preservation and healed sites, respectively (P > .05). The mean crestal bone remodeling during the observation period was 0.63 and 0.45 mm on the mesial and 0.48 and 0.12 mm on the distal aspects in the ridge preservation and healed sites, respectively (P < .05). The results of this study demonstrated stable MBL and survival of implants placed in sites following ridge preservation with xenograft as well as nongrafted healed sites.

Treatment of multiple recession defects with vestibular incision subperiosteal tunnel access (VISTA): A retrospective pilot study utilizing digital analysis.

OBJECTIVE: To examine the correlation between initial site-specific characteristics of patients with multiple gingival recession defects and the outcome of root coverage therapy. MATERIALS AND METHODS: Pretherapy and post-therapy study models of 21 patients (154 teeth) with multiple gingival recession defects, treated with Vestibular Incision Subperiosteal Tunnel Access (VISTA), were optically scanned. Three-dimensional analysis of superimposed preoperative and postoperative images was performed. Linear and surface root coverage were calculated and correlated to various clinical and/or anatomical parameters. A multilevel statistical analysis was conducted, adjusting for the correlation among multiple observations. RESULTS: The mean percentages of linear root coverage were 96.2 ± 13.1% and 84.3 ± 14.4% for Miller Class I/II and Class III recessions, respectively. The mean percentages of root surface area coverage were 92.1 ± 12.0% and 78.6 ± 15.7% for Miller Class I/II and III defects, respectively. Root prominence, initial recession width and posterior tooth type were negatively correlated with linear and root surface area coverage. Initial recession depth was negatively correlated with root surface area coverage. Initial gingival margin thickness was positively associated with both linear and root surface area coverage. CONCLUSION: The results of the present study identified important positive and negative site-specific characteristics that may have utility in predicting the outcome of root coverage. CLINICAL SIGNIFICANCE: This study used sensitive 3-dimensional digital analysis tools to examine the correlation between initial site-specific characteristics of patients with multiple gingival recession defects and the outcome of periodontal root coverage therapy. Results demonstrated that initial root prominence, loss of interdental tissue (Miller Class III), molar tooth type, initial recession depth and width were negatively correlated with the outcome of periodontal root coverage achieved. Conversely, initial gingival margin thickness was associated with increased percentage of root coverage. These site-specific characteristics may serve as important risk indicators to predict the outcome of root coverage procedure.

A Histologic and Histomorphometric Retrospective Analysis of the Outcomes of Ridge Preservation Using Anorganic Bovine Bone Minerals and a Nonresorbable Membrane.

The objective of this study was to examine wound healing in extraction sockets following ridge preservation and the outcome of implants placed in those sites. Extraction sockets (N = 31) were grafted with anorganic bovine bone mineral (ABBM) and covered with dense polytetrafluoroethylene membrane. Bone cores obtained during implant placement were examined histologically and histomorphometrically. Percentages of vital bone and residual graft were 37.5% ± 21.3% and 12.5% ± 8.9%, respectively. New vital bone showed a negative correlation with patient age. Percentage of vital bone formation in sockets was correlated with neither postgraft wound healing time nor peri-implant marginal bone level.

Histological and Histomorphometric Response to SocketKAP™ and SocketKAGE™ Used for Ridge Preservation and Repair: Results From a Randomized Controlled Clinical Trial.

PURPOSE: This study investigated the histologic tissue response to SocketKAP and SocketKAGE as novel devices designed for ridge preservation. MATERIALS AND METHODS: This randomized controlled clinical trial recruited participants among patients who presented to a university dental clinic. The study protocol entailed randomization into 5 intervention groups after tooth extraction: unassisted healing of intact sockets (group A), SocketKAP (group B), anorganic bovine bone minerals (ABBM) plus SocketKAP (group C), unassisted healing of sockets with dehiscence (group D), and SocketKAGE plus ABBM plus SocketKAP (group E). The primary outcome variable was bone volume fraction of total volume (BV/TV). Secondary outcome variables were percentages of residual graft material (RG) and void volume (VV). One-way analysis of variance was run on BV/TV, RG, and VV based on the independent variable (treatment groups). RESULTS: Bone core samples were harvested from participants (N = 22) who presented for implant installation at 6 months after extraction. Sockets without biomaterial filler (groups A and B) showed more mature bone compared with grafted sockets. In groups in which sockets were filled with biomaterial (groups C and E), vital bone was observed in direct apposition to the graft particles. In group E, remnants of SocketKAGE were not readily discernable at 6 months. No substantial inflammatory infiltrate or other adverse histologic patterns were detected. Quantitative analysis showed a statistically significant difference in BV/TV between groups A and C (P = .028) and between groups A and E (P = .019). CONCLUSIONS: Histologic and histomorphometric results showed that the application of SocketKAP and SocketKAGE did not interfere with wound healing of extraction sockets. In agreement with previous reports, the percentage of BV/TV within sites with ABBM was smaller than within sites without biomaterial. The favorable histologic response to SocketKAP and SocketKAGE observed in the present study provided additional insights to the authors' previous studies showing the benefits of these devices in decreasing postextraction dimensional alterations of alveolar bone and tissue contour.

Retrospective Analysis of the Outcome of Ridge Preservation with Anorganic Bovine Bone Minerals: Microcomputed Tomographic Assessment of Wound Healing in Grafted Extraction Sockets.

A total of 68 extraction sockets were grafted with anorganic bovine bone mineral and covered by dense polytetrafluoroethylene membrane. Quantitative analysis of three-dimensional microcomputed tomography imaging of core samples retrieved after a mean of 21.0 ± 14.2 weeks revealed 40.1% bone volume fraction (bone volume [BV]/total volume [TV]) and 12% residual graft. Evidence of de novo bone formation was observed in the form of discrete islands of newly formed bone in direct apposition to graft particles, separated from parent bone. Anterior sockets exhibited a significantly higher percentage of residual graft compared to premolar sockets (P = .05). The BV/TV and percentage of residual graft correlated well with histomorphometric analysis of the same sites, but not with implant outcomes.

Design, Synthesis, and Antimicrobial Evaluation of a Novel Bone-Targeting Bisphosphonate-Ciprofloxacin Conjugate for the Treatment of Osteomyelitis Biofilms.

Osteomyelitis is a major problem worldwide and is devastating due to the potential for limb-threatening sequelae and mortality. Osteomyelitis pathogens are bone-attached biofilms, making antibiotic delivery challenging. Here we describe a novel osteoadsorptive bisphosphonate-ciprofloxacin conjugate (BV600022), utilizing a "target and release" chemical strategy, which demonstrated a significantly enhanced therapeutic index versus ciprofloxacin for the treatment of osteomyelitis in vivo. In vitro antimicrobial susceptibility testing of the conjugate against common osteomyelitis pathogens revealed an effective bactericidal profile and sustained release of the parent antibiotic over time. Efficacy and safety were demonstrated in an animal model of periprosthetic osteomyelitis, where a single dose of 10 mg/kg (15.6 µmol/kg) conjugate reduced the bacterial load by 99% and demonstrated nearly an order of magnitude greater activity than the parent antibiotic ciprofloxacin (30 mg/kg, 90.6 µmol/kg) given in multiple doses. Conjugates incorporating a bisphosphonate and an antibiotic for bone-targeted delivery to treat osteomyelitis biofilm pathogens constitute a promising approach to providing high bone-antimicrobial potency while minimizing systemic exposure.

An open randomized controlled clinical trial to evaluate ridge preservation and repair using SocketKAP(™) and SocketKAGE(™) : part 2 - three-dimensional alveolar bone volumetric analysis of CBCT imaging.

OBJECTIVES: The aims of this study were (i) to evaluate the efficacy of ridge preservation and repair procedures involving the application of SocketKAP(™) and SocketKAGE(™) devices following tooth removal and (ii) to evaluate alveolar bone volumetric changes at 6 months post-extraction in intact sockets or those with facial wall dehiscence defects using 3-dimensional pre- and postoperative CBCT data. MATERIALS AND METHODS: Thirty-six patients required 61 teeth extracted. Five cohorts were established: Group A: Intact Socket Negative Control Group B: Intact Socket + SocketKAP(™) Group C: Intact Socket Filled with Anorganic Bovine Bone Mineral (ABBM) + SocketKAP(™) Group D: Facial Dehiscence Socket Negative Control Group E: Facial Dehiscence Socket Filled with ABBM + SocketKAP(™) + SocketKAGE(™) . Preoperative CBCT scans were obtained followed by digital subtraction of the test teeth. At 6 months post-extraction, another CBCT scan was obtained. The pre- and postoperative scans were then superimposed, allowing highly accurate quantitative determination of the 3D volumetric alveolar bone volume changes from baseline through 6 months. RESULTS: Significant volumetric bone loss occurred in all sockets, localized mainly in the 0-3 mm zone apical to the ridge crest. For intact sockets, SocketKAP(™) + ABBM treatment led to a statistically significant greater percentage of remaining mineralized tissue volume when compared to negative control group. A significant difference favoring SocketKAP(™) + SocketKAGE(™) + ABBM treatment was observed for sockets with facial dehiscence defects compared to the negative control group. CONCLUSIONS: SocketKAP(™) , with ABBM, appears effective in limiting post-extraction volumetric bone loss in intact sockets, while SocketKAP(™) + SocketKAGE + ABBM appears effective in limiting post-extraction bone loss in sockets with dehiscence defects.

An open randomized controlled clinical trial to evaluate ridge preservation and repair using SocketKAP(™) and SocketKAGE(™) : part 1-three-dimensional volumetric soft tissue analysis of study casts.

OBJECTIVES: The aims of this study were to evaluate (i) the efficacy of ridge preservation and repair involving SocketKAP(™) and SocketKAGE(™) devices following tooth removal; and (ii) ridge contour changes at 6 months post-extraction in intact sockets and sockets with dehiscence defects. MATERIAL AND METHODS: Thirty-six patients required a total of 61 teeth to be extracted. Five cohorts were established with groups A-C involving intact sockets and groups D and E involving facial dehiscence: (A) Negative Control; (B) SocketKAP(™) alone; (C) Anorganic Bovine Bone Mineral (ABBM) + SocketKAP(™) ; (D) Negative Control; and (E) ABBM + SocketKAP(™)  + SocketKAGE(™) . Preoperative CBCT and laser-scanned casts were obtained. Teeth segmented from preoperative CBCT were merged with study cast images to allow for digital removal of teeth from the casts. Volumetric measurements of ridge contour were performed. Images of preoperative and 6 months post-operative casts were superimposed to measure ridge contour changes. RESULTS: Post-extraction contour loss occurred in all sockets primarily in the crestal 3 mm but was also detected up to 6 mm from alveolar crest. For intact sockets, SocketKAP(™) or SocketKAP(™)  + ABBM interventions led to greater percentages of remaining ridge contour when compared to controls. A significant difference favoring SocketKAP(™)  + SocketKAGE(™)  + ABBM treatment was observed for sockets with facial dehiscence when compared to controls. CONCLUSION: SocketKAP(™) , with or without ABBM, significantly limited post-extraction ridge contour loss in intact sockets. In the absence of a group treated with only the SocketKAGE(™) , it is not possible to determine its efficacy, although the combination of SocketKAGE(™)  + SocketKAP(™)  + ABBM was effective in limiting post-extraction ridge contour loss in sockets with dehiscence defects.

Accidental migration of a dental implant into the ethmoid sinus following a transalveolar sinus elevation procedure.

BACKGROUND: Migration of a dental implant into the paranasal sinuses may be the result of sinus membrane perforation, loss of osseointegration, and lack of initial stability. The majority of displaced implants migrate into the maxillary sinus, which may cause sinusitis. PURPOSE: The purpose of this study is to report an extremely rare ethmoid sinus migration of a dental implant after crestal approach in a resorbed posterior maxilla. MATERIALS AND METHODS: A 60-year old Korean male with a noncontributory medical history was referred from a local clinic to remove the migrated dental implant in the right ethmoid sinus. The patient had symptoms of mild sinusitis. The implant had been placed 6 months earlier through the bone-added transalveolar approach in a severely resorbed maxilla. RESULTS: The displaced implant was removed through the intraoral approach. A lateral window was made and an endoscopic surgery was performed to remove the implant. Healing was uneventful, and sinusitis symptom had ceased. CONCLUSION: The crestal approach for severely resorbed posterior maxillae should be performed when there is a potential for primary stability. If bone quality is poor and initial stability cannot be achieved, lateral window sinus elevation procedure is a better option for successful implant placement. Migrated implant may be removed with antrostomy and endoscopic surgery.

Accuracy of linear measurement using cone-beam computed tomography at different reconstruction angles.

PURPOSE: This study was performed to evaluate the effect of changing the orientation of a reconstructed image on the accuracy of linear measurements using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Forty-two titanium pins were inserted in seven dry sheep mandibles. The length of these pins was measured using a digital caliper with readability of 0.01 mm. Mandibles were radiographed using a CBCT device. When the CBCT images were reconstructed, the orientation of slices was adjusted to parallel (i.e., 0°), +10°, +12°, -12°, and -10° with respect to the occlusal plane. The length of the pins was measured by three radiologists, and the accuracy of these measurements was reported using descriptive statistics and one-way analysis of variance (ANOVA); p<0.05 was considered statistically significant. RESULTS: The differences in radiographic measurements ranged from -0.64 to +0.06 at the orientation of -12°, -0.66 to -0.11 at -10°, -0.51 to +0.19 at 0°, -0.64 to +0.08 at +10°, and -0.64 to +0.1 at +12°. The mean absolute values of the errors were greater at negative orientations than at the parallel position or at positive orientations. The observers underestimated most of the variables by 0.5-0.1 mm (83.6%). In the second set of observations, the reproducibility at all orientations was greater than 0.9. CONCLUSION: Changing the slice orientation in the range of -12° to +12° reduced the accuracy of linear measurements obtained using CBCT. However, the error value was smaller than 0.5 mm and was, therefore, clinically acceptable.

Effect of titanium and stainless steel posts in detection of vertical root fractures using NewTom VG cone beam computed tomography system.

PURPOSE: Vertical root fracture (VRF) is a common complication in endodontically treated teeth. Considering the poor prognosis of VRF, a reliable and valid detection method is necessary. Cone beam computed tomography (CBCT) has been reported to be a reliable tool for the detection of VRF; however, the presence of metallic intracanal posts can decrease the diagnostic values of CBCT systems. This study evaluated and compared the effects of intracanal stainless steel or titanium posts on the sensitivity, specificity, and accuracy of VRF detection using a NewTom VG CBCT system. MATERIALS AND METHODS: Eighty extracted single-rooted teeth were selected and sectioned at the cemento-enamel junction. The roots were divided into two groups of 40. Root fracture was induced in the test group by using an Instron machine, while the control group was kept intact. Roots were randomly embedded in acrylic blocks and radiographed with the NewTom VG, both with titanium and stainless steel posts and also without posts. Sensitivity, specificity, and accuracy values were calculated as compared to the gold standard. RESULTS: The sensitivity, specificity, and accuracy of VRF diagnosis were significantly lower in teeth with stainless steel and titanium posts than in those without posts. Interobserver agreement was the highest in teeth without posts, followed by stainless steel posts, and then titanium posts. CONCLUSION: Intracanal posts significantly decreased the VRF diagnostic values of CBCT. The stainless steel posts decreased the diagnostic values more than the titanium posts.

Dietary phosphorus exacerbates bone loss induced by cadmium in ovariectomized rats.

OBJECTIVE: Postmenopausal bone loss can be exacerbated by environmental contaminants, including the heavy metal cadmium (Cd). We hypothesized that incorporating phosphorus (P) into the diet would lead to the chelation of Cd into P, preventing its absorption and subsequent bone loss. METHODS: To test this hypothesis, we used ovariectomized rats as a model of postmenopausal osteoporosis to examine the deleterious effects of Cd on bone with and without added P. Fifty 3-month-old ovariectomized Sprague-Dawley rats were assigned to five treatment groups (n = 10 per group) for 3 months as follows: (1) control; (2) 50 ppm Cd; (3) 50 ppm Cd plus 1.2% P; (4) 200 ppm Cd; and (5) 200 ppm Cd plus 1.2% P. RESULTS: Cd plus P caused a significant loss of whole body (P = 0.0001 and P < 0.001) and femoral (P = 0.0005 and P < 0.001) bone mineral density (BMD) and bone mineral content, respectively, and a loss of fourth lumbar vertebra BMD and bone mineral content (P < 0.0001 and P < 0.001, respectively). Nonetheless, 200 ppm Cd plus 1.2% P had the most deleterious effects on whole body and femoral BMD. For femoral neck microstructural properties, 50 ppm Cd plus 1.2% P caused an increase in trabecular separation, whereas 200 ppm Cd plus 1.2% P caused a decrease in bone volume-to-total volume ratio, a decrease in trabecular number, and an increase in trabecular separation and structural model index. CONCLUSIONS: Our findings indicate that Cd exposure, along with high intake of P, may be a public health hazard with respect to bone health.

Biocompatibility and microstructural analysis of osteopromotive property of allogenic demineralized dentin matrix.

PURPOSE: Bone grafting materials and methods have been used to compensate anatomical limitations and improve ridge and sinus structure for implant placement. The objective of this study was to evaluate the osteopromotive property of allogenic demineralized dentin matrix (DDM) as a bone grafting material using micro-computed tomography and blood biomarkers. MATERIALS AND METHODS: Two surgical bone defects were created on the skull of 30 female New Zealand White rabbits. Experimental defects in 24 rabbits were filled with allogenic DDM applying guided bone regeneration technique, while the control defects were covered by membrane without receiving the graft. In the remaining six rabbits, both defects were left empty and these rabbits served as control for blood biomarkers. The 24 experimental rabbits were sacrificed after 15, 30, 60, and 90 days (n = 6 at each time point). Blood samples were collected from all rabbits at the baseline, 48 hours postsurgery, and at each time point. RESULTS: Bone thickness was significantly higher in the experimental group at all time points. Micro-computed tomography results showed increased bone mass and superior bone quality in the experimental group. At all time points except for 48 hours postsurgery, the white blood cell count was numerically higher in control rabbits compared to experimental rabbits, suggesting a lack of inflammation or infection due to allogenic DDM. Bone-specific alkaline phosphatase activities were lower in both experimental and control groups at all time points in comparison to baseline values, which is indicative of either a lower rate of bone formation or bone turnover. CONCLUSIONS: Within the limitations of this study, allogenic demineralized dentin matrix significantly increased bone mass and improved bone quality without causing an inflammatory reaction or infection.

Flaxseed reverses atherosclerotic lesion formation and lowers lipoprotein(a) in ovarian hormone deficiency.

OBJECTIVE: The incidence of cardiovascular disease dramatically increases during menopause, and postmenopausal women seek natural alternatives to hormone therapy. Flaxseed can slow the progression of atherosclerotic lesion formation; however, it is not known whether it can reverse formation that has already occurred. METHODS: Seventy-two female Golden Syrian hamsters were randomly divided into six groups (n = 12), sham-operated (sham) or ovariectomized (ovx), and kept on the same diet for 120 days to allow for atherosclerotic lesion development. After this 120-day period, whole flaxseed was introduced to the diets of hamsters in three of the groups: group 1 (sham + casein); group 2 (ovx + casein); group 3 (ovx + 7.5% flaxseed); group 4 (ovx + 15% flaxseed); group 5 (ovx + 22.5% flaxseed); and group 6 (ovx + 17ß-estradiol). This diet was maintained for an additional 120 days. Lesion regression was examined histologically, and serum was analyzed for total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, Apo A, Apo B, and lipoprotein(a). RESULTS: Results showed that 15% and 22.5% flaxseed, compared with ovx animals, significantly reduced lipoprotein(a) (4.4 mg/dL [ovx] vs 2.15 mg/dL [15% flaxseed] and 0.3 mg/dL [22.5% flaxseed]; P < 0.05) and Apo B (2.8 mg/dL [ovx] vs 2.4 mg/dL [15% flaxseed] and 2.5 mg/dL [22.5% flaxseed]). Flax reduced by 67% the number of animals with aortic arch lesions. CONCLUSIONS: All three doses of flax reduce the severity of lesion formation compared with ovx controls. These results support the efficacy of flaxseed in reducing cardiovascular disease risk.