The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients

Microleakage and microtensile bond strength of silorane-based and dimethacrylate-based restorative systems.

To evaluate the microleakage and bond strengths (microTBS) of silorane-based (SBC) and dimethacrylate-based (DBC) restorative systems. The null hypotheses are: 1) there is no difference in microleakage between the resin composites and the adhesive systems tested at the enamel and dentin margins; 2) there is no significant difference in microTBS between the composite restorative systems using self-etch and etch-and-rinse adhesive versions. Microleakage: Class V cavity preparations with cervical margin in dentin were performed on pristine extracted human molars and were randomly distributed among the following three groups: Group 1-DBC/etch-and-rinse adhesive system (Filtek™ Supreme Ultra/Adper™ Single Bond Plus, 3M ESPE, www.3MESPE.com); Group 2-SBC/self-etch adhesive (Filtek LS Low Shrink Posterior Restorative System/LS self-etch adhesive, 3M ESPE); Group 3-DBC/self-etch adhesive (Filtek Supreme Ultra/ Adper Easy Bond Self-Etch, 3M ESPE). Restorations were thermocycled and immersed in 0.2 percent methylene blue dye for 24 hours. Samples were assessed visually under 10x magnification; microTBS: Bond sticks (0.9 mm2) were prepared from each group and tested on a universal testing machine. The Kruskal-Wallis test revealed no significant difference in microleakage among the experimental groups at the enamel margin (P=0.191). At the dentin margins, silorane/self-etch restorative system showed significantly less leakage than the dimethacrylate/etch-and-rinse restorative system (P=0.008). Tukey\u27s B rank order test showed that the dimethacrylate/etch-and-rinse restorative system presented the highest microTBS. SBC/self-etch system showed less microleakage at the dentin margins, while DBC/etch-and-rinse system presented higher bond strength

Comparison of mechanical properties of five commercial dental core build-up materials.

This study aimed to evaluate and compare the mechanical properties of five commercial core materials using fracture toughness (FT), Knoop hardness number (KHN), diametral tensile strength (DTS), and dynamic elastic moduli (DEM). Composite material specimens were produced (Rock Core, CosmeCore, ParaCore, MultiCore Flow, and Filtek Supreme Plus). The FT test (n = 15) was performed using notchless triangular prism (NTP) specimens. FT was determined using an Instron testing machine. KHN (n = 3) was evaluated using three indentations applied on each specimen. DTS test (n = 15) was measured using an Instron testing machine. The density. of the specimens (n = 3) was determined by water displacement method. Dynamic Young\u27s, shear moduli, and Poisson\u27s ratio (n = 3) were measured by an ultrasonic method. Statistical analysis was conducted using ANOVA and a Tukey B rank order test (P = 0.05). Rock Core presented the lowest FT values. Filtek Supreme Plus and CosmeCore exhibited significantly higher KHN values than the rest of the materials. CosmeCore had the highest DTS value, which was statistically significant only compared to Rock Core. For DEM, Filtek Supreme Plus exhibited significantly higher Young\u27s and shear moduli than the rest of the materials (P \u3c 0.05). Results demonstrated significant differences in the FT, KHN, and DTS values of the core build-up materials tested. According to the elastic behavior of the core composite materials, Rock Core had the lowest Young\u27s values

Enamel wear opposing different surface conditions of different CAD/CAM ceramics

Objective: The aim of this study was to evaluate bovine enamel wear opposed to four different ceramic substrates (CEREC) in the glazed and polished conditions. Method and Materials: Sixty-three ceramic (IPS Empress CAD, Paradigm C, Vitablocs Mark II) and fourteen composite resin (MZ100) styli were prepared. Ceramics were subdivided into three surface conditions (n = 7), unpolished, polished, and glazed, and the composite resin (n = 7) into unpolished and polished. All styli were used as wear antagonists opposing bovine enamel blocks (8 mm × 9 mm) in an oral wear simulator. Wear tests were conducted at 30 N abrasion and 70 N attrition forces applied at 1.7 Hz for 5,000 simulated mastication cycles. Abrasion and attrition wear were evaluated using an automatic profilometer. Statistical analyses were conducted using Tukey’s B rank order test, P = .05. Results: For bovine enamel opposing glazed Vitablocs, abrasion and attrition wear showed a volume loss significantly higher than bovine enamel opposing polished Vitablocs (P \u3c .05). For attrition wear, bovine enamel opposing glazed Vitablocs and untreated Paradigm C showed a volume loss higher than bovine enamel opposing the other ceramic conditions. Conclusion: Abrasion and attrition wear of bovine enamel opposing antagonist ceramic was affected according to the ceramic surface condition and the ceramic material. Antagonistic wear against the studied ceramic materials and conditions exhibited wear rates within the range of normal enamel. In addition, the glaze layer presented as a protection, exhibiting fewer cracks and less loss of material on the ceramic surface. © 2013 by Quintessence Publishing Co Inc

Failure modes of Y-TZP abutments with external hex implant-abutment connection determined by fractographic analysis

© 2016 Elsevier Ltd. Yttria-stabilized tetragonal zirconia (Y-TZP) was introduced as ceramic implant abutments due to its excellent mechanical properties. However, the damage patterns for Y-TZP abutments are limited in the literature. Fractographic analyses can provide insights as to the failure origin and related mechanisms. The purpose of this study was to analyze fractured Y-TZP abutments to establish fractographic patterns and then possible reasons for failure. Thirty two prefabricated Y-TZP abutments on external hex implants were retrieved from a single-load-to failure test according to the ISO 14801. Fractographic analyses were conducted under polarized-light estereo and scanning electro microscopy. The predominant fracture pattern was abutment fracture at the connecting region. Classic fractographic features such as arrest lines, hackle, and twist hackle established that failure started where Y-TZP abutments were in contact with the retention screw edges. The abutment screw design and the loading point were the reasons for localized stress concentration and fracture patterns

Effects of artificial aging conditions on yttria-stabilized zirconia implant abutments

© 2016 Editorial Council for the Journal of Prosthetic Dentistry Statement of problem Most ceramic abutments are fabricated from yttria-stabilized tetragonal zirconia (Y-TZP). However, Y-TZP undergoes hydrothermal degradation, a process that is not well understood. Purpose The purpose of this in vitro study was to assess the effects of artificial aging conditions on the fracture load, phase stability, and surface microstructure of a Y-TZP abutment. Material and methods Thirty-two prefabricated Y-TZP abutments were screwed and tightened down to external hexagon implants and divided into 4 groups (n = 8): C, control; MC, mechanical cycling (1×106 cycles; 10 Hz); AUT, autoclaving (134°C; 5 hours; 0.2 MPa); and TC, thermal cycling (104 cycles; 5°/55°C). A single-load-to-fracture test was performed at a crosshead speed of 0.5 mm/min to assess the assembly\u27s resistance to fracture (ISO Norm 14801). X-ray diffraction (XRD) analysis was applied to observe and quantify the tetragonal-monoclinic (t-m) phase transformation. Representative abutments were examined with high-resolution scanning electron microscopy (SEM) to observe the surface characteristics of the abutments. Load-to-fracture test results (N) were compared by ANOVA and Tukey test (α=.05). Results XRD measurements revealed the monoclinic phase in some abutments after each aging condition. All the aging conditions reduced the fracture load significantly (P\u3c.001). Mechanical cycling reduced the fracture load more than autoclaving (P=.034). No differences were found in the process of surface degradation among the groups; however, the SEM detected grinding-induced surface flaws and microcracks. Conclusions The resistance to fracture and the phase stability of Y-TZP implant abutments were susceptible to hydrothermal and mechanical conditions. The surface microstructure of Y-TZP abutments did not change after aging conditions

Therapeutic mammaplasty is a safe and effective alternative to mastectomy with or without immediate breast reconstruction

Background: Therapeutic mammaplasty (TM) may be an alternative to mastectomy, but few well designed studies have evaluated the success of this approach or compared the short-term outcomes of TM with mastectomy with or without immediate breast reconstruction (IBR). Data from the national iBRA-2 and TeaM studies were combined to compare the safety and short-term outcomes of TM and mastectomy with or without IBR. Methods: The subgroup of patients in the TeaM study who underwent TM to avoid mastectomy were identified, and data on demographics, complications, oncology and adjuvant treatment were compared with those of patients undergoing mastectomy with or without IBR in the iBRA-2 study. The primary outcome was the percentage of successful breast-conserving procedures in the TM group. Secondary outcomes included postoperative complications and time to adjuvant therapy. Results: A total of 2916 patients (TM 376; mastectomy 1532; mastectomy and IBR 1008) were included in the analysis. Patients undergoing TM were more likely to be obese and to have undergone bilateral surgery than those having IBR. However, patients undergoing mastectomy with or without IBR were more likely to experience complications than the TM group (TM: 79, 21·0 per cent; mastectomy: 570, 37·2 per cent; mastectomy and IBR: 359, 35·6 per cent; P < 0·001). Breast conservation was possible in 87·0 per cent of patients who had TM, and TM did not delay adjuvant treatment. Conclusion: TM may allow high-risk patients who would not be candidates for IBR to avoid mastectomy safely. Further work is needed to explore the comparative patient-reported and cosmetic outcomes of the different approaches, and to establish long-term oncological safety