Browsing by Subject "Implant"
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Item Breast Implant Reconstruction in the Ptotic Patient: Evaluation of Wise and Vertical Skin Sparing Mastectomy(Sage, 2024-03-12) Holohan, M. Margaret; Diaz, Stephanie M.; Newsom, Keeley; Smith, Alex; Fan, Betty; Imeokparia, Folasade O.; Fisher, Carla S.; Ludwig, Kandice K.; Lester, Mary E.; Hassanein, Aladdin H.; Surgery, School of MedicineIntroduction: Post-mastectomy reconstruction in patients with severe breast ptosis can be challenging. Traditionally, a skin sparing mastectomy (SSM) with a circumareolar incision or a horizontal elliptical extension results in a long, horizontally-oriented scar in the central breast. The Wise pattern SSM with an inferiorly-based dermal flap addresses skin redundancy and provides added vascularized implant coverage in ptotic patients with macromastia. The purpose of this study is to compare outcomes in ptotic patients undergoing SSM with Wise pattern and a modified vertical technique which also uses de-epithelialized excess skin under the incision. Methods: A retrospective chart review was performed on patients that underwent SSM using a Wise or vertical skin reducing technique. The Wise pattern was performed using an inferiorly-based dermal flap and the vertical method used a laterally-based dermal flap covering the implant/tissue expander (TE). Results: SSM with the use of autoderm was performed in 42 patients (67 breasts) using either the Wise (n = 49 breasts) or vertical (n = 18 breasts) method. Both groups had similar BMI (35.4). The prepectoral plane was used in 93.5% of Wise pattern patients and all vertical patients. All cases of seroma and hematoma occurred in the Wise pattern group (10.2%). Mastectomy skin necrosis requiring unplanned return to surgery for debridement occurred in 20.4% of those undergoing Wise pattern SSM and 11.1% undergoing the vertical pattern (p = 0.49). Conclusion: Severely ptotic patients undergoing SSM have a high risk of skin necrosis. A dermal flap under the closure has the advantage of vascularized tissue reinforcing the wound in implant based reconstruction. The vertical pattern SSM using a laterally-based dermal flap may be a safe, simple alternative to the Wise pattern in select patients.Item Contraceptive implant use duration is not associated with breakthrough pregnancy among women living with HIV and using efavirenz: a retrospective, longitudinal analysis(Wiley, 2022) Stalter, Randy M.; Amorim, Gustavo; Mocello, A. Rain; Jakait, Beatrice; Shepherd, Bryan E.; Musick, Beverly; Bernard, Caitlin; Bukusi, Elizabeth A.; Wools-Kaloustian, Kara; Cohen, Craig R.; Yiannoutsos, Constantin T.; Patel, Rena C.; Implant/Efavirenz Study Group; East Africa IeDEA regional consortium; Biostatistics, School of Public HealthIntroduction: Contraceptive implants containing etonogestrel and levonorgestrel have emerged as popular contraceptive options among women in areas of high HIV burden in sub-Saharan Africa. However, recent pharmacokinetic data have shown drug-drug interactions between implants and efavirenz-containing antiretroviral therapy (ART), reducing the effectiveness of the implants. Here, we evaluated pregnancy incidence in 6-month intervals following implant initiation among women using efavirenz and contraceptive implants to assess whether the risk of breakthrough pregnancy is higher after specific periods of implant use. Methods: We used data from a retrospective longitudinal analysis of women living with HIV ages 18-45 years in western Kenya who attended HIV-care facilities between 2011 and 2015. We used Cox proportional hazard models to compute hazard ratios (HRs) for breakthrough pregnancy by implant type and ART regimen. Depending on the model, we adjusted for socio-demographic and clinical factors, programme, site and interaction between calendar time and ART regimen. We utilized inverse probability weights (IPWs) to account for three sampling phases (electronic medical record [EMR], chart review and phone interview) and calculated overall parameter estimates. Results: Women contributed 14,768 woman-years from the largest sampling phase (EMR). The median age was 31 years. Women used etonogestrel implants for 26-69% of the time and levonorgestrel implants for 7-31% of the time, depending on the sampling phase. Women used efavirenz, nevirapine or no ART for 27-33%, 40-46% and 15-26% of follow-ups, respectively. When combining sampling phases, there was little evidence to suggest that the relative hazard of pregnancy among efavirenz-containing ART users relative to nevirapine-containing ART changed with length of time on implants: IPW-adjusted HR of 3.1 (CI: [1.5; 6.4]) at 12 months, 3.4 (CI: [1.8; 6.3]) at 24 months, 3.8 (CI: [1.9; 7.7]) at 36 months and 4.2 (CI: [1.6; 11.1]) at 48 months (interaction p-value = 0.88). Similarly, no significant change in HRs over time was found when comparing women not using ART to nevirapine-containing ART users (interaction p-value = 0.49). Conclusions: We did not find evidence to suggest implants being more fallible from drug-drug interactions with efavirenz at later time intervals of implant use. Thus, we would not recommend shortening the duration of implant use or replacing implants sooner when concomitantly used with efavirenz.Item Fracture Resistance Behaviors of Titanium-Zirconium and Zirconia Implants(Wiley, 2021) Hanes, Brenda; Sochacki, Sabrina Feitosa; Phasuk, Kamolphob; Levon, John A.; Morton, Dean; Lin, Wei-Shao; Prosthodontics, School of DentistryPurpose To evaluate the fracture resistance behaviors of titanium-zirconium, one-piece zirconia, and two-piece zirconia implants restored by zirconia crowns and different combinations of abutment materials (zirconia and titanium) and retention modes (cement-retained and screw-retained zirconia crowns). Material and Methods Three research groups (n=12) were divided according to combinations of abutment material, retention mode, and implant type. In the control group (TTC), titanium-zirconium implants (∅ 4.1 mm RN, 12 mm, Roxolid; Straumann USA) and prefabricated titanium abutments (RN synOcta Cementable Abutment, H 5.5 mm; Straumann USA) were used to support cement-retained zirconia crowns. In the second group (ZZC), one-piece zirconia implants (PURE Ceramic Implant Monotype, ∅ 4.1 mm RD, 12 mm, AH 5.5 mm; Straumann USA) were used to support cement-retained zirconia crowns. In the third group (ZTS), two-piece zirconia implants (PURE Ceramic Implant, ∅ 4.1 mm RD, 12 mm) and prefabricated titanium abutments (CI RD PUREbase Abutment, H 5.5 mm) were used to support screw-retained zirconia crowns. All zirconia crowns were manufactured in the same anatomic contour with a 5-axis dental mill and blended 3 and 5 mol% yttria-stabilized zirconia (LayZir A2). Implants were inserted into specimen holders made of epoxy resin-glass fiber composite. All specimens were then subject to artificial aging in an incubator at 37 C° for 90 days. Fracture resistance of specimen assemblies was tested under static compression load using the universal testing machine following ISO14801 specification. The peak fracture loads were recorded. All specimens were examined at the end of the test microscopically at 5 × and 10 × magnification to detect any catastrophic failures. Comparisons between groups for differences in peak fracture load were made using Wilcoxon Rank Sum tests and Weibull and Kaplan-Meier survival analyses (α = .05). Results The TTC group (942 ±241 N) showed significantly higher peak fracture loads than the ZZC (645 ±165 N) and ZTS (650 ±124 N) groups (p < .001), while there was no significant difference between ZZC and ZTS groups (p = 0.940). The survival probability based on the Weibull and Kaplan-Meier models demonstrated different failure molds between titanium- zirconium and zirconia implants, in which the TTC group remained in the plastic strain zone for a longer period before fracture when compared to ZZC and ZTS groups. Catastrophic failures, with implant fractures at the embedding level or slightly below, were only observed in the ZZC and ZTS groups. Conclusions Cement-retained zirconia crowns supported by titanium-zirconium implants and prefabricated titanium abutments showed superior peak fracture loads and better survival probability behavior. One-piece zirconia implants with cement-retained zirconia crowns and two-piece zirconia implants with screw-retained zirconia crowns on prefabricated titanium abutment showed similar peak fracture loads and survival probability behavior. Titanium-zirconium and zirconia implants could withstand average intraoral mastication loads in the incisor region. This study was conducted under static load, room temperature (21.7 °C), and dry condition, and full impacts of intraoral hydrothermal aging and dynamic loading conditions on the zirconia implants should be considered and studied further.Item Novel bioactive tetracycline-containing electrospun polymer fibers as a potential antibacterial dental implant coating(SpringerLink, 2017-07) Shahi, R. G.; Albuquerque, M. T. P.; Münchow, E. A.; Blanchard, S. B.; Gregory, R. L.; Bottino, M. C.; Biomedical Sciences and Comprehensive Care, School of DentistryThe purpose of this investigation was to determine the ability of tetracycline-containing fibers to inhibit biofilm formation of peri-implantitis-associated pathogens [i.e., Porphyromonas gingivalis (Pg), Fusobacterium nucleatum (Fn), Prevotella intermedia (Pi), and Aggregatibacter actinomycetemcomitans (Aa)]. Tetracycline hydrochloride (TCH) was added to a poly(DL-lactide) [PLA], poly(ε-caprolactone) [PCL], and gelatin [GEL] polymer blend solution at distinct concentrations to obtain the following fibers: PLA:PCL/GEL (TCH-free, control), PLA:PCL/GEL + 5 % TCH, PLA:PCL/GEL + 10 % TCH, and PLA:PCL/GEL + 25 % TCH. The inhibitory effect of TCH-containing fibers on biofilm formation was assessed by colony-forming units (CFU/mL). Qualitative analysis of biofilm inhibition was done via scanning electron microscopy (SEM). Statistical significance was reported at p < 0.05. Complete inhibition of biofilm formation on the fibers was observed in groups containing TCH at 10 and 25 wt%. Fibers containing TCH at 5 wt% demonstrated complete inhibition of Aa biofilm. Even though a marked reduction in CFU/mL was observed with an increase in TCH concentration, Pi proved to be the most resilient microorganism. SEM images revealed the absence of or a notable decrease in bacterial biofilm on the TCH-containing nanofibers. Collectively, our data suggest that tetracycline-containing fibers hold great potential as an antibacterial dental implant coating.Item Pregnancies among women living with HIV using contraceptives and antiretroviral therapy in western Kenya: a retrospective, cohort study(BMC, 2021-08-13) Patel, Rena C.; Amorim, Gustavo; Jakait, Beatrice; Shepherd, Bryan E.; Mocello, A. Rain; Musick, Beverly; Bernard, Caitlin; Onono, Maricianah; Bukusi, Elizabeth A.; Wools-Kaloustian, Kara; Cohen, Craig R.; Yiannoutsos, Constantin T.; Biostatistics, School of Public HealthBackground: Preventing unintended pregnancies is paramount for women living with HIV (WLHIV). Previous studies have suggested that efavirenz-containing antiretroviral therapy (ART) reduces contraceptive effectiveness of implants, but there are uncertainties regarding the quality of the electronic medical record (EMR) data used in these prior studies. Methods: We conducted a retrospective, cohort study of EMR data from 2011 to 2015 among WLHIV of reproductive age accessing HIV care in public facilities in western Kenya. We validated a large subsample of records with manual chart review and telephone interviews. We estimated adjusted incidence rate ratios (aIRRs) with Poisson regression accounting for the validation sampling using inverse probability weighting and generalized raking. Results: A total of 85,324 women contributed a total of 170,845 women-years (w-y) of observation time; a subset of 5080 women had their charts reviewed, and 1285 underwent interviews. Among implant users, the aIRR of pregnancy for efavirenz- vs. nevirapine-containing ART was 1.9 (95% CI 1.6, 2.4) using EMR data only and 3.2 (95% CI 1.8, 5.7) when additionally using both chart review and interview validated data. Among efavirenz users, the aIRR of pregnancy for depomedroxyprogesterone acetate (DMPA) vs. implant use was 1.8 (95% CI 1.5, 2.1) in EMR only and 2.4 (95% CI 1.0, 6.1) using validated data. Conclusion: Pregnancy rates are higher when contraceptive implants are concomitantly used with efavirenz-containing ART, though rates were similar to leading alternative contraceptive methods such as DMPA. Our data provides policymakers, program staff, and WLHIV greater confidence in guiding their decision-making around contraceptive and ART options. Our novel, 3-phase validation sampling provides an innovative tool for using routine EMR data to improve the robustness of data quality.Item Prolonged Use of the Etonogestrel Implant and Levonorgestrel Intrauterine Device - Two Years Beyond FDA-Approved Duration(Elsevier, 2017-06) McNicholas, Colleen; Swor, Erin; Wan, Leping Wan; Peipert, Jeffrey F.; Medicine, School of MedicineThe subdermal contraceptive implant, and the 52mg levonorgestrel intrauterine device (IUD) are currently FDA-approved for three and five years of use respectively. Limited available data has suggested both of these methods are effective beyond that time. Demonstration of prolonged effectiveness will improve the cost-effectiveness of the device, and potentially patient continuation and satisfaction. Objective To evaluate the effectiveness of the contraceptive implant and the 52-mg hormonal intrauterine device (IUD) in women using the method for two years beyond the current FDA-approved duration. Study Design We initiated this ongoing prospective cohort study in January 2012. We are enrolling women using the contraceptive implant or 52-mg levonorgestrel IUD for a minimum of 3 and 5 years, respectively (started IUD in 2007 or later or implant in 2009 or later). Demographic and reproductive health histories, as well as objective body mass index (BMI) were collected. Implant users were offered periodic venipuncture for analysis of serum etonogestrel levels. The primary outcome, unintended pregnancy rates, was calculated per 100 woman-years. We analyzed baseline demographic characteristics using chi-square test and Fisher Exact test, and compared serum ENG levels stratified by body mass index using the Kruskal-Wallis test. Results Implant users (n=291) have contributed 444.0 women-years of follow-up. There have been no documented pregnancies in implant users during the two years of post-expiration follow-up. Calculated failure rates in the fourth and fifth years for the implant are calculated as 0 (one-sided %97.5 confidence interval (CI) 0–1.48) per 100 woman years at four years and 0 (one-sided %97.5 CI 0–2.65) per 100 women years at five years. Among 496 levonorgestrel IUD users, 696.9 women-years of follow-up have been completed. Two pregnancies have been reported. The failure rate in the sixth year of use of the levonorgestrel IUD is calculated as 0.25(%95 CI 0.04–1.42) per 100 women year; failure rate during the seventh year is 0.43 (%95 CI 0.08–2.39) per 100 women years. Among implant users with serum etonogestrel results, the median etonogestrel level at the time of method expiration was 207.7 pg/mL (range 63.8–802.6 pg/mL), 166.1 pg/mL (range 67.9 25.0 – 470.5 pg/mL) at the end of the fourth year, and 153.0 pg/mL (range 72.1–538.8 pg/mL) at the end of the fifth year. Median ENG levels were compared by BMI at each time point and a statistical difference was noted at the end of four years of use with overweight women having the highest serum ENG (195.9 pg/ml: range 25.0–450.5) when compared to normal (178.9 pg/ml: range 87.0–463.7) and obese (137.9 pg/ml: range 66.0–470.5) women (p=0.04). Conclusion This study indicates that the contraceptive implant and 52-mg hormonal IUD continue to be highly effective for at least two additional years of use. Serum etonogestrel evaluation demonstrates median levels remain above the ovulation threshold of 90pg/ml for women of in all BMI classes.