Passing The Scalpel: A Student Initiative in Identifying and Addressing Unmet Needs in Dental Education.

PURPOSE: Becoming an oral-maxillofacial surgeon is often challenging for young trainees. The purpose of this manuscript is to explore how a student-led group, which emphasizes networking, mentorship, and academic opportunities, may impact one's journey to becoming an oral-maxillofacial surgeon. PATIENTS AND METHODS: This was a cross-sectional descriptive study where a 5-question Likert-type survey was administered to students who matriculated into residency and participated in a student-led group called Passing The Scalpel (PTS). This survey evaluated the value of PTS in providing exposure, career decision-making, networking/mentorship, and camaraderie. The results were analyzed, and statistical outcomes were evaluated. RESULTS: There was an 80.5% response rate (n = 29). Question 1 regarding first exposure to oral-maxillofacial surgery had a mean score of 2.55 (standard deviation [SD] = 1.35; χ2 = 15.39; P < .05). Question 2 regarding choosing oral-maxillofacial surgery as a career had a mean score of 3.66 (SD = 1.11; χ2 = 10.84; P < .05). Question 3 regarding offering mentorship and networking had a mean score of 4.14 (SD = 0.92; χ2 = 27.81; P < .05). Question 4 regarding increasing applicant camaraderie had a mean score of 4.21 (SD = 0.77; χ2 = 36.71; P < .05). Question 5 regarding the importance of PTS within a dental curriculum had a score of 4.48 (SD = 0.68; χ2 = 41.89; P < .05). CONCLUSION: PTS is an effective student-led initiative that emphasizes early exposure, networking, and mentorship opportunities and encourages students in choosing oral-maxillofacial surgery as a specialty. PTS demonstrates that student-led initiatives can fulfill unmet needs in the dental curriculum.

Successive Reimplantation of Dental Implants Into Sites of Previous Failure.

PURPOSE: To evaluate the survival rates of dental implants that had been reimplanted in sites of previous failure, including first, second, and third reimplantations, and investigate the various factors that could affect the reimplantation outcomes. MATERIALS AND METHODS: All dental implants placed in sites of previous implant failure were identified, including first, second, and third reimplantations. The survival rates were assessed, and epidemiologic and clinical data were collected and analyzed to evaluate the effects on reimplantation survival. RESULTS: The survival rate for the total number of initial implants placed was 95.4% (5280 of 5532). For the 208 patients with failed implants, the survival rate was 62.0% (412 of 664). The survival rate of the implants placed in the sites of previous failure (first reimplantation) was 77.4% (137 of 177 implants). A statistically significant difference was found (P = .0001) between the survival rates of implants placed for the first time and implants placed into sites of previous failure. The survival rate of the second reimplantations was 72.7% (16 of 22). The survival rate of the third reimplantations was 50.0% (1 of 2). Each implant and reimplant group demonstrated a statistically significant greater percentage of postoperative pain reports in the failure group than in the survival group. A significantly greater percentage of early failures (failures occurring before abutment connection) occurred compared with late failures for each implant and reimplant group. CONCLUSIONS: Dental implants placed in sites of previous implant failure had lower survival rates than those of the initial implants, and our findings suggested that the survival rates will be consecutively lower with each successive reimplantation at the same site. Implant and reimplant failures were associated with higher rates of postoperative pain reports and were more often early failures. Such suggestions could improve clinicians' prediction for implant failure and allow for optimization of the conditions to improve implant survival.

The effect of α-mating factor secretion signal mutations on recombinant protein expression in Pichia pastoris.

The methylotrophic yeast, Pichia pastoris, has been genetically engineered to produce many heterologous proteins for industrial and research purposes. In order to secrete proteins for easier purification from the extracellular medium, the coding sequence of recombinant proteins is initially fused to the Saccharomyces cerevisiae α-mating factor secretion signal leader. Extensive site-directed mutagenesis of the prepro-region of the α-mating factor secretion signal sequence was performed in order to determine the effects of various deletions and substitutions on expression. Though some mutations clearly dampened protein expression, deletion of amino acids 57-70, corresponding to the predicted 3rd alpha helix of α-mating factor secretion signal, increased secretion of reporter proteins horseradish peroxidase and lipase at least 50% in small-scale cultures. These findings raise the possibility that the secretory efficiency of the leader can be further enhanced in the future.

Conserved C-terminal domain of spider tubuliform spidroin 1 contributes to extensibility in synthetic fibers.

Spider silk is renowned for its extraordinary mechanical properties, having a balance of high tensile strength and extensibility. To date, the majority of studies have focused on the production of dragline silks from synthetic spider silk gene products. Here we report the first mechanical analysis of synthetic egg case silk fibers spun from the Latrodectus hesperus tubuliform silk proteins, TuSp1 and ECP-2. We provide evidence that recombinant ECP-2 proteins can be spun into fibers that display mechanical properties similar to other synthetic spider silks. We also demonstrate that silks spun from recombinant thioredoxin-TuSp1 fusion proteins that contain the conserved C-terminal domain exhibit increased extensibility and toughness when compared to the identical fibers spun from fusion proteins lacking the C-terminus. Mechanical analyses reveal that the properties of synthetic tubuliform silks can be modulated by altering the postspin draw ratios of the fibers. Fibers subject to increased draw ratios showed elevated tensile strength and decreased extensibility but maintained constant toughness. Wide-angle X-ray diffraction studies indicate that postdrawn fibers containing the C-terminal domain of TuSp1 have more amorphous content when compared to fibers lacking the C-terminus. Taken together, these studies demonstrate that recombinant tubuliform spidroins that contain the conserved C-terminal domain with embedded protein tags can be effectively spun into fibers, resulting in similar tensile strength but increased extensibility relative to nontagged recombinant dragline silk proteins spun from equivalently sized proteins.