A novel cryo-embedding method for in-depth analysis of craniofacial mini pig bone specimens.

The disconnect between preclinical and clinical results underscores the imperative for establishing good animal models, then gleaning all available data on efficacy, safety, and potential toxicities associated with a device or drug. Mini pigs are a commonly used animal model for testing orthopedic and dental devices because their skeletons are large enough to accommodate human-sized implants. The challenge comes with the analyses of their hard tissues: current methods are time-consuming, destructive, and largely limited to histological observations made from the analysis of very few tissue sections. We developed and employed cryo-based methods that preserved the microarchitecture and the cellular/molecular integrity of mini pig hard tissues, then demonstrated that the results of these histological, histochemical, immunohistochemical, and dynamic histomorphometric analyses e.g., mineral apposition rates were comparable with similar data from preclinical rodent models. Thus, the ability to assess static and dynamic bone states increases the translational value of mini pig and other large animal model studies. In sum, this method represents logical means to minimize the number of animals in a study while simultaneously maximizing the amount of information collected from each specimen.

Effect of staining and denture cleaning on color stability of differently polymerized denture base acrylic resins.

BACKGROUND: Denture hygiene is an important factor to remove dental plaque and discoloration, to provide optimal oral health, and to prevent denture stomatitis. AIM: The purpose of this study was to evaluate the effect of coffee staining and denture cleaner on the color stability of two differently polymerized (heat and microwave) denture acrylic resin in vitro. MATERIALS AND METHODS: Two commonly used denture base acrylic resins and effervesecnt tablet form denture cleaner were used in this study. Disc-shaped specimens from each acrylic resin were polymerized according to the manufacturer's instructions (n = 7). Color values were recorded before and after immersion in distilled water (I), denture cleaner (II), coffee (III), and coffee + denture cleaner (IV) with a tristimulus colorimeter using CIEDE2000 color difference formula. Two-way analysis of variance (ANOVA) and Fisher's least significant difference tests were used for multiple comparisons at a 95% confidence level (P < 0.05). Surface topography of the acrylic resin denture base specimens before and after immersion were taken under 500 × magnification. RESULTS: The two-way ANOVA revealed significant interactions between denture base resins and solutions (P < 0.001). Immersion in denture cleaner and coffee solution caused significant color changes in acrylic resin denture bases. CONCLUSION: Heat- and microwave-polymerized acrylic denture base resins can show different color stability. Immersion in coffee and denture cleaner solutions can cause noticeable color changes.

Augmentation of chronic rotator cuff healing using adipose-derived stem cell-seeded human tendon-derived hydrogel.

Rotator cuff (RTC) repair outcomes are unsatisfactory due to the poor healing capacity of the tendon bone interface (TBI). In our preceding study, tendon hydrogel (tHG), which is a type I collagen rich gel derived from human tendons, improved biomechanical properties of the TBI in a rat chronic RTC injury model. Here we investigated whether adipose-derived stem cell (ASC)-seeded tHG injection at the repair site would further improve RTC healing. Rats underwent bilateral supraspinatus tendon detachment. Eight weeks later injured supraspinatus tendons were repaired with one of four treatments. In the control group, standard transosseous suture repair was performed. In the ASC, tHG, tHGASC groups, ASC in media, tHG, and ASC-seeded tHG were injected at repair site after transosseous suture repair, respectively. Eight weeks after repair, the TBI was evaluated biomechanically, histologically, and via micro CT. Implanted ASCs were detected in ASC and tHGASC groups 7 weeks after implantation. ACS implantation improved bone morphometry at the supraspinatus insertion on the humerus. Injection of tHG improved biomechanical properties of the repaired TBI. RTC healing in tHGASC group was significantly better than control but statistically equivalent to the tHG group based on biomechanical properties, fibrocartilage area at the TBI, and bone morphometry at the supraspinatus insertion. In a rat RTC chronic injury model, no biomechanical advantage was gained with ASC augmentation of tHG. Clinical Significance: Tendon hydrogel augmentation with adipose derived stem cells does not significantly improve TBI healing over tHG alone in a chronic rotator cuff injury model. © 2019 Orthopaedic Research Society. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

An individualised treatment algorithm for tumour stage 1 glottic squamous cell carcinoma.

OBJECTIVE: To report and discuss the outcome of a treatment algorithm for patients with tumour stage 1 glottic squamous cell carcinoma. METHOD: A retrospective outcome analysis study was performed using data from a tertiary referral centre. RESULTS: Sixty-nine patients were treated with radiotherapy and 26 with surgery, in accordance with the treatment algorithm. Five-year overall survival rates were the same for both treatment groups (92 per cent). Five-year disease-specific survival rates were 100 per cent for surgery, 98 per cent for radiotherapy and 99 per cent overall. The overall 5-year laryngeal preservation rate was 89.1 per cent, being 95.7 per cent for surgery patients and 86.7 per cent for radiotherapy patients (p = 0.502). There was no significant association between laryngeal preservation rates and age (p = 0.779), anterior commissure involvement (p = 0.081), tumour stage (1a or 1b) (p = 0.266) or treatment modality (surgery or radiotherapy; p = 0.220). There was no significant difference in local recurrence rates between the two treatment groups (19.3 per cent for radiotherapy vs 10.0 per cent for surgery; p = 0.220). The overall 5-year regional recurrence rate was 1.2 per cent. CONCLUSION: Tumour stage 1 glottic carcinoma can be managed with different treatment modalities, following an individualised treatment algorithm, with results comparable to published outcomes.