Faculty Bibliography

OBJECTIVES: To observe and to compare histologically and histomorphometrically, the combined effect of drilling sequence and implant diameter in vivo. MATERIAL AND METHODS: A total of 72 alumina-blasted and acid-etched Ti-6Al-4V implants with three different diameters (3.75, 4.2, and 5 mm, n = 24 for each group) were placed in the right and left tibiae of 12 beagle dogs. Within the same diameter group, half of the implants were inserted after a simplified drilling procedure (pilot drill + final diameter drill) on one tibia and the other half were placed using the conventional drilling procedure on the other tibia. After 1 week, half of the animals (n = 6) were sacrificed, and the other half was sacrificed after 5 weeks (n = 6). The retrieved bone-implant samples were subjected to non-decalcified histologic sectioning, and the bone-to-implant contact (BIC) and the bone area fraction occupancy (BAFO) were analyzed. Primary statistical analysis used a mixed model analysis of variance with significance level set at P < 0.05. RESULTS: Histologic observation showed that at 1 week, immature woven bone formed in vicinity of the implant, whereas at 5 weeks, the woven bone was replaced by lamellar bone, which formed in proximity with the implant. Histomorphometrically, the simplified technique was associated with significantly greater BIC and BAFO after 1 week. Differences between techniques were not longer apparent after 5 weeks, but BAFO was inversely and significantly associated with implant diameter at that time. CONCLUSIONS: The simplified technique did not impair either early or late bone formation for any tested implant diameter; however, wider diameters were associated with less bone formation at longer healing times for both techniques.

Purpose: This study aimed to evaluate the survival probability of four narrow-diameter implant systems when subjected to fatigue loading. Materials and Methods: Seventy-two narrow-diameter implants to be restored with single-unit crowns were divided into four groups (n = 18): Astra Tech (3.5-mm diameter), with a standard connection (ASC); BioHorizon (3.4-mm diameter), with a standard connection (BSC); Intra-Lock (3.4-mm diameter), with a standard multilobular connection (ISC); and Intra-Lock (3.4-mm diameter), with a modified square connection (IMC). The corresponding abutments were screwed onto the implants, and standardized metal crowns (maxillary central incisors) were cemented and subjected to step-stress accelerated life testing in water. Use-level probability Weibull curves and reliability for 100,000 cycles at 150 and 200 N (90% two-sided confidence intervals) were calculated. Polarized light and scanning electron microscopes were used to access the failure modes. Results: The calculated survival probability for 100,000 cycles at 150 N was approximately 93% in group ASC, 98% in group BSC, 94% in group ISC, and 99% in group IMC. At 200 N, the survival rate was estimated to be approximately < 0.1% for ASC, 77% for BSC, 34% for ISC, and 93% for IMC. Abutment screw fracture was the main failure mode for all groups. Conclusions: Although the probability of survival was not significantly different among systems at a load of 150 N, a significant decrease was observed at 200 N for all groups except IMC.

The purpose of this report is to present a case series of gingiva-colored abutments utilized to meet patients, esthetic needs. The color of the abutment was determined by evaluating the color of the patients, marginal gingiva using a digital shade guide. Thereafter, anodic oxidation was performed on computer-aided design/computer-assisted manufacture abutments. The baseline digital color information was compared with the color of the gingiva after 1.5 years in three patients. The gingival colors as well as the marginal bone and soft tissue levels after 1.5 years were comparable to the baseline values. Thus, the gingiva-colored abutments obtained by anodic oxidation provided improved esthetics, especially for patients with thin gingival biotypes.

I do not pretend to understand the moral universe. The arc is a long one. My eye reaches but little ways. I cannot calculate the curve and complete the figure by experience of sight. I can divine it by conscience. And from what I see I am sure it bends toward justice. -Theodore Parker, 19th century abolitionist and Unitarian minister Four years ago, I wrote a chapter for a volume since published titled, "The Search for the Legacy of the USPHS Syphilis Study at Tuskegee: Reflective Essays Based Upon Findings From the Tuskegee Legacy Project."1 (Am J Public Health. Published online ahead of print July 17, 2014: e1-e3. doi:10.2105/AJPH.2014.302127).

BACKGROUND: Nipple-sparing mastectomy (NSM) is a recent advance in the therapeutic and prophylactic management of breast cancer; however, the procedure is associated with increased reconstructive complications. Data on NSM after previous breast augmentation are limited. OBJECTIVES: The authors compared reconstructive complications after NSM between patients with previously augmented breasts and a larger cohort that had not undergone prior augmentation. An approach to NSM that involves 2-stage reconstruction in augmented patients is also described. METHODS: Medical records of NSMs performed at New York University Langone Medical Center from 2006 to 2013 were reviewed. Data points evaluated included patient characteristics, comorbidities, breast implant plane, and reconstructive complications. Fisher's exact and t tests were used for the comparisons. RESULTS: During the study period, NSMs were performed in 17 augmented breasts at this institution. After NSM, 15 of these breasts underwent implant-based reconstruction and 2 breasts underwent microvascular free flaps. Reconstructive complications included 1 hematoma managed nonoperatively (5.9%) and 1 partial necrosis of the nipple-areola complex (NAC) (5.9%). Compared with the larger nonaugmented cohort (n = 332), patients with previously augmented breasts had fewer complications, and there were no statistically significant differences in the rates of mastectomy flap necrosis, partial NAC necrosis, complete NAC necrosis, hematoma, capsular contracture, explantation, implant displacement, seroma, or breast cellulitis. CONCLUSIONS: The results indicate that NSM reconstruction is associated with minimal complications in patients with previous augmentation mammaplasty. Level of Evidence: 4.

PURPOSE:: This clinical and histological study evaluated the healing of extraction sockets after implantation of a biphasic calcium sulfate (CS) alone or in combination with a gamma-radiated human mineralized allograft. MATERIALS AND METHODS:: Ten healthy adult patients participated in the study. A minimum of 2 teeth, per patient, extracted for different reasons were evaluated. Each socket was randomly filled to the crest with either (a) a biphasic CS or (b) large particulate gamma-radiated human mineralized allograft in combination with a biphasic CS. RESULTS:: No complications during reentry of the socket site during bone core retrieval, such as inflammation/immunogenic response, were observed. Histological findings showed a mean new bone (NB) of 33% for sockets filled with biphasic CS and 31% for sockets filled with biphasic CS in combination with allograft material. There was no statistically significant difference in the percentage of NB and the presence of soft tissue between graft materials. CONCLUSION:: Biphasic CS used alone or in combination with an allograft resulted in the same amount of NB formation in alveolar ridge preservation procedures.

Osseointegration of metallic devices has been one of the most successful treatments in rehabilitative dentistry and medicine over the past five decades. While highly successful, the quest for designing surgical instrumentation and associated implantable devices that hastens osseointegration has been perpetual and has often been approached as single variable preclinical investigations. The present manuscript presents how the interplay between surgical instrumentation and device macrogeometry not only plays a key role on both early and delayed stages of osseointegration, but may also be key in how efficient smaller length scale designing (at the micrometer and nanometer scale levels) may be in hastening early stages of osseointegration.

BACKGROUND: It is known that physico/chemical alterations on biomaterial surfaces have the capability to modulate cellular behavior, affecting early tissue repair. Such surface modifications are aimed to improve early healing response and, clinically, offer the possibility to shorten the time from implant placement to functional loading. Since FAK and Src are intracellular proteins able to predict the quality of osteoblast adhesion, this study evaluated the osteoblast behavior in response to nanometer scale titanium surface texturing by monitoring FAK and Src phosphorylations. METHODOLOGY: Four engineered titanium surfaces were used for the study: machined (M), dual acid-etched (DAA), resorbable media microblasted and acid-etched (MBAA), and acid-etch microblasted (AAMB). Surfaces were characterized by scanning electron microscopy, interferometry, atomic force microscopy, x-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. Thereafter, those 4 samples were used to evaluate their cytotoxicity and interference on FAK and Src phosphorylations. Both Src and FAK were investigated by using specific antibody against specific phosphorylation sites. PRINCIPAL FINDINGS: The results showed that both FAK and Src activations were differently modulated as a function of titanium surfaces physico/chemical configuration and protein adsorption. CONCLUSIONS: It can be suggested that signaling pathways involving both FAK and Src could provide biomarkers to predict osteoblast adhesion onto different surfaces.

Found in most mesenchymally derived organs, mesenchymal stem cells are undifferentiated cells capable of developing into many cell types. Adipose stem cells are a type of mesenchymal stem cell easily extracted from lipoaspirate, often readily available, and are conformable to the tissue defect. Their ability for self-renewal, unlimited proliferation and proangiogenic, and immunomodulatory properties have made them attractive adjuncts in plastic surgery. Since the discovery of pluripotent cells in adipose tissue, plastic surgeons have applied the technology toward improving wound healing, soft tissue augmentation, and tissue engineering. More recently, some surgeons have used adipose stem cells in cancer reconstruction. By mixing lipoaspirate with concentrated fractions of adipose stem cells through a technique termed cell-assisted lipotransfer, plastic surgeons have claimed improved aesthetic results. Promising early results have been tempered by in vitro and animal studies demonstrating increased tumor proliferation and metastasis rates with the use of adipose and other mesenchymal stem cells. This review provides a succinct yet comprehensive overview of the current literature evaluating the oncologic risks associated with adipose stem cell use in cancer.

STRUCTURED ABSTRACT: Study Design. Animal modelObjective. Determine whether Amicar and TXA inhibit spine fusion volumeSummary of Background Data. Amicar and TXA are antifibrinolytics used to reduce perioperative bleeding. Prior in vitro data showed that antifibrinolytics reduce osteoblast bone mineralization. This study tested whether antifibrinolytics Amicar and TXA inhibit spine fusion.Methods. Posterolateral L4-L6 fusion was performed in fifty mice, randomized into groups of ten, that received the following treatment before and after surgery: (1) Saline; (2) TXA 100mg/kg; (3) TXA 1000mg/kg; (4) Amicar 100 mg/kg; (5) Amicar 1000 mg/kg. High-resolution plane radiography was performed after 5 weeks and micro-CT was performed at the end of the 12-week study. Radiographs were graded using the Lenke scale. Micro-CT was used to quantify fusion mass bone volume. One-way analysis of variance (ANOVA) by ranks with Kruskal-Wallis testing was used to compare the radiographic scores. One-way ANOVA with least-significant differences (LSD) post-hoc testing was used to compare the micro-CT bone volume.Results. The average (+/- SD) bone volume/total volume (%) measured in the saline, TXA 100 mg/kg, TXA 1000 mg/kg, Amicar 100 mg/kg and Amicar 1000 mg/kg groups were 10.8+/-2.3, 9.7+/-2.2, 13.4+/-3.2, 15.5+/-5.2 and 17.9+/-3.5%, respectively. There was a significant difference in the Amicar 100 mg/kg (p < 0.05) and Amicar 1000 mg/kg (p < 0.001) groups compared to saline. There was greater bone volume in the Amicar groups compared to the TXA group (p < 0.001). There was more bone volume in the TXA 1000 mg/kg group compared to TXA 100 mg/kg (p < 0.05) but the bone volume in neither of the TXA groups was different to saline (p = 0.49). There were no between-group differences observed using plane radiographic scoring.Conclusions. Amicar significantly enhanced the fusion bone mass in a dose-dependent manner while TXA did not have a significant effect on fusion compared to saline control.These data are in contrast to prior in vitro data that antifibrinolytics inhibit osteoblast bone mineralization.