The effects of keratin-coated titanium on osteoblast function and bone regeneration.

Wool derived keratin, due to its demonstrated ability to promote bone formation, has been suggested as a potential bioactive material for implant surfaces. The aim of this study was to assess the effects of keratin-coated titanium on osteoblast functionin vitroand bone healingin vivo. Keratin-coated titanium surfaces were fabricated via solvent casting and molecular grafting. The effect of these surfaces on the attachment, osteogenic gene, and osteogenic protein expression of MG-63 osteoblast-like cells were quantifiedin vitro. The effect of these keratin-modified surfaces on bone healing over three weeks using an intraosseous calvaria defect was assessed in rodents. Keratin coating did not affect MG-63 proliferation or viability, but enhanced osteopontin, osteocalcin and bone morphogenetic expressionin vitro. Histological analysis of recovered calvaria specimens showed osseous defects covered with keratin-coated titanium had a higher percentage of new bone area two weeks after implantation compared to that in defects covered with titanium alone. The keratin-coated surfaces were biocompatible and stimulated osteogenic expression in adherent MG-63 osteoblasts. Furthermore, a pilot preclinical study in rodents suggested keratin may stimulate earlier intraosseous calvaria bone healing.

Aniracetam: An Evidence-Based Model for Preventing the Accumulation of Amyloid-ß Plaques in Alzheimer's Disease.

 Alzheimer's disease is the leading cause of dementia in the world. It affects 6 million people in the United States and 50 million people worldwide. Alzheimer's disease is characterized by the accumulation of amyloid-ß plaques (Aß), an increase in tau protein neurofibrillary tangles, and a loss of synapses. Since the 1990s, removing and reducing Aß has been the focus of Alzheimer's treatment and prevention research. The accumulation of Aß can lead to oxidative stress, inflammation, neurotoxicity, and eventually apoptosis. These insults impair signaling systems in the brain, potentially leading to memory loss and cognitive decline. Aniracetam is a safe, effective, cognitive-enhancing drug that improves memory in both human and animal studies. Aniracetam may prevent the production and accumulation of Aß by increasing α-secretase activity through two distinct pathways: 1) increasing brain derived neurotrophic factor expression and 2) positively modulating metabotropic glutamate receptors. This is the first paper to propose an evidence-based model for aniracetam reducing the accumulation and production of Aß.

Clinician- and Patient-Centred Outcomes of Digital Impressions in Infants with Cleft Lip and Palate: A Systematic Review.

This systematic review examines the effectiveness of digital impressions in infants with cleft lip and palate (CLP), focusing on accuracy, operator preferences, and parents' perceptions. The PICO-formulated focused questions assessed the accuracy and operator preference of digital impressions compared to conventional impressions in infants with cleft lip and palate, while also exploring parents' perceptions as patient-centred outcomes. Electronic and manual searches were conducted in five databases including PubMed, Scopus, Web of Science, Embase, and Cochrane Library; to acquire grey literature, Google Scholar was also consulted. Both experimental and observational studies that used digital impressions in the clinical care of infants with CLP were included. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the quality of the included studies. Out of 503 records, 12 studies met the inclusion criteria. The accuracy assessment included surface discrepancy and intra-arch measurements. Surface discrepancy studies showed variations in the premaxillary segments, while intra-arch measurements revealed no significant differences. Operators preferred digital impressions, citing reduced stress and streamlined workflows. Parents expressed a clear preference for digital over conventional impressions. The conclusions drawn were substantiated by weak evidence due to the limited number and the high risk of bias of the included studies. Challenges remain here, warranting continued research to enhance accuracy and assess parents' preferences, ensuring optimal outcomes for infants with CLP.

Impact of root canal preparation using two single-file systems on the intra-radicular microbiome of teeth with primary apical periodontitis.

OBJECTIVES: This study aimed to describe the effects of two single-file systems on the diversity of the endodontic microbiome of teeth with primary asymptomatic apical periodontitis. MATERIALS AND METHODS: The root canals from single-rooted teeth with apical periodontitis were prepared using either the Reciproc Blue (RB) or the XP-endo Shaper (XPS) instrument system. The latter was followed by a supplementary step with the XP-endo Finisher (XPF) instrument. For irrigation, 5.25% sodium hypochlorite was used. Root canal samples were taken at the baseline (S1), after preparation (S2), and after the supplementary step (S3). DNA was extracted and subjected to high-throughput sequencing using the MiSeq Illumina platform. RESULTS: Samples from 10 teeth from the RB and 7 from the XPS group were subjected to DNA sequencing. Initial samples differed significantly from post-preparation samples in bacterial diversity, with no significant difference when comparing the two instrument systems. The most dominant phyla in S2 were Bacteroidetes, Proteobacteria, Firmicutes, Fusobacteria, and Actinobacteria. The same phyla were found to dominate baseline samples and samples taken after using XPF, but with differences in the ranking of the most dominant ones. At the genus level, the most dominant genera identified after RB instrumentation were Bacteroidaceae [G-1], Fusobacterium, and Staphylococcus, while the most dominant genera after XPS instrumentation were Fusobacterium and Porphyromonas. These genera were also dominant in the initial samples. CONCLUSIONS: Both treatment protocols had measurable effects on the root canal microbial diversity, with no significant differences between them. Most of the dominant taxa involved in the primary infection and probably in the aetiology of apical periodontitis were eliminated or substantially reduced. CLINICAL RELEVANCE: The most dominant taxa that persisted after instrumentation were Fusobacterium, Porphyromonas, Staphylococcus, and Bacteroidaceae [G-1].

A retrospective study on the prognostic factors and success, survival, and failure outcomes of treated endodontic-periodontal lesions.

OBJECTIVES: The objective of this retrospective study was to determine possible prognostic factors of endodontic-periodontal lesions and to compare success, survival, and failure outcomes of treated endodontic-periodontal lesions across different treatment modalities, demographic variables, and anatomical tooth variations. MATERIALS AND METHODS: Data was collected from patient records in the patient management system (Salud, Titanium Solutions) from the Griffith University Dental Clinic between January 2008 and December 2021. The search strategy used the terms "endodontic periodontal lesion," "periodontal endodontic lesion," "endo perio lesion," "perio endo lesion," and "EPL." The 88 cases which met inclusion and exclusion criteria were analyzed. RESULTS: The overall success rate was 46.6%, with 21.6% of teeth surviving and 31.8% of teeth failing. Bone loss extending to the apical third (OR = 0.3, 95% CI [0.104, 0.866]), and probing depths of 5-7 mm (OR = 0.147, 95% CI [0.034, 0.633]) and 8-10 mm (OR = 0.126, 95% CI [0.029, 0.542]) were associated with a statistically significant lower odds of success (p < .05). A history of no periodontal disease (OR = 7.705, 95% CI [1.603, 37.037]) was associated with a statistically significant higher odds of success (p < .05). CONCLUSION: Practitioners should be aware of bone loss to the apical third, deep probing depths, and a history of periodontal disease as possible prognostic factors that can affect the success rate when treating endodontic-periodontal lesions. Further research with more stringent control over operator factors should be done to investigate these variables.

Efficacy of an impression disinfectant solution after repeated use: An in vitro study.

Statement of problem: There are very few studies using Benzalkonium Chloride (BAC) as an active disinfection agent for immersion techniques and there are no studies investigating the efficacy of repeated use of a disinfectant solution. Purpose: This study evaluated an impression disinfectant by testing bacterial contamination of disinfectant batches used in a clinical setting after repeated use. Materials and methods: Liquid samples were collected from impression disinfectant solutions used to disinfect dental impressions taken at a university dental clinic. The experimental samples (500 ml from 1 L of solution) were collected from teaching and professional clinics and the in-house commercial processing laboratory and stored at room temperature each day of clinic operation over five weeks. To determine to what extent the disinfectant efficacy of the active product decreased over time, the following tests were carried out: a. Inoculation b. Gram staining technique c. Matrix Assisted Laser Desorption/Ionization Mass spectrometry (MALDI- MS). Microbial growth was monitored and photographed. A culture revival was made from colonies grown on sheep blood agar, to isolate pure colonies incubated for 24 h at 37 °C. Each morphologically distinct type of colony was gram stained and MALDI spectrometry analysis was performed using the VITEK MS (BioMerieux Inc.). Results: Evidence of growth of bacteria was detected in teaching clinics' samples, and no growth from the professional clinic or the commercial laboratory. Conclusions: The study demonstrated that the impression disinfectant solution tested is effective against common oral bacteria, despite some rare species such as Bacillus circulans, Bacillus horneckiae, Bacillus altitudinis/pumilus and Bacillus cereus showing evidence of survival in solutions used for disinfection of impressions. However, in a high use teaching clinic environment its efficacy deteriorated. Though a second level disinfection protocol in the commercial laboratory-maintained impression disinfection.

Effect of pulp capping materials on odontogenic differentiation of human dental pulp stem cells: An in vitro study.

OBJECTIVES: Migration and differentiation of human dental pulp stem cells (hDPSCs) is a vital and key factor in the success of reparative dentin formation for maintenance of pulp vitality. Pulp capping materials are used to stimulate DPSCs to induce new dentin formation. Thus, the aim of the present study was to compare the response of DPSCs to four commercially available pulp capping materials: a bioactive bioceramic (Material 1), a nonresinous ready-to-use bioceramic cement (Material 2), a bioactive composite (Material 3), and a biocompatible, dual-cured, resin-modified calcium silicate (Material 4). MATERIALS AND METHODS: hDPSCs were isolated and cultured from freshly extracted teeth and were then characterized by flow cytometry and multilineage differentiation. Discs prepared from pulp capping materials were tested with hDPSCs and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, cell migration assay and odontogenic differentiation assay was performed. Expression of osteogenic markers (osteopontin, RUNX family transcription factor 2, osteocalcin) and the odontogenic marker (dentin sialophosphoprotein) was detected using reverse transcription-polymerase chain reaction. RESULTS: Materials 1, 2, and 3 generated more cell viability than Material 4. Furthermore, Material 4 showed the least wound exposure percentage, while Material 3 showed the highest percentage. Enhanced mineralization was found in hDSCPs cultured with Material 3, followed by Material 1, and then Material 2, while Material 4 revealed the least calcified mineralization. CONCLUSIONS: The results of this study were inconclusive regards contemporary bioceramic materials designed for vital pulp therapy as they have different effects on hDPSC. Further testing for cytotoxicity using live-dead staining, animal experiments, clinical trials, and independent analyses of these biomaterials is necessary for clinicians to make an informed decision for their use.

In vitro effects of wool-derived keratin on human dental pulp-derived stem cells for endodontic applications.

In this study we examine the influence of wool-derived keratin intermediate filament proteins (kIFPs) on human dental pulp-derived stem cells (hDPSCs). kIFPs were diluted (10 mg/mL to 0.001 mg/mL) in cell culture media. Effects on hDPSCs proliferation were measured using Alamar blue assay. Keratin concentrations of 1 mg/mL and 0.1 mg/mL were tested for odontogenic differentiation and mineralisation. Alkaline phosphatase (ALP) quantification (7th, 14th, and 21st days), alizarin red S (AR-S) staining and calcium quantification (21st day), reverse transcription polymerase chain reaction (RT-PCR, collagen expression), and immunocytochemical staining for dentin matrix protein (DMP) were performed. hDPSCs showed higher proliferation with kIFPs of 0.1 mg/mL or less (p < 0.0001). The 0.1 mg/mL keratin concentration promoted odontogenic differentiation, confirmed by increased ALP activity, significant calcium deposits (AR-S staining, p < 0.05), up-regulated collagen expression (RT-PCR, p < 0.05), and positive DMP staining. These results suggest that kIFPs could be a potential biomaterial for pulp-dentin regeneration.

Impact of Removable Partial Dentures on Masticatory Performance in Partial Edentulism: A Systematic Review.

PURPOSE: Removable partial dentures (RPDs) are widely used in clinical dental practice as a cost-effective treatment to restore the oral function. Clear understanding of the effect of partial dentures on masticatory performance is important for clinical decision making in prosthodontics. The purpose of this systematic review is to evaluate the impact of RPDs on masticatory performance (MP) of partially edentulous subjects. MATERIAL AND METHODS: Electronic database and hand searches were conducted to explore clinical trials reporting the evidence of the effect of metal and acrylic based removable partial dentures on mastication. The validated objective and subjective measures of assessment of mastication were included. The article selection, data extraction and assessment of risk of bias were conducted by two reviewers independently. RESULTS: Out of 11200 studies, one randomised control trial and 23 clinical trials met the inclusion criteria. Positive impact on different parameters of masticatory function after RPD treatment, was reported in 14 studies. Subjective evaluation of chewing ability (CA) displayed an improvement in 83.3% of studies, while improvement was evidenced only in 69.5% of studies upon objective evaluation. Majority of the studies were reporting data on free end saddles. Out of the 13 studies associated with bilateral free end saddle dentures, 9 studies showed a positive effect on masticatory efficiency. Various factors were found to have an impact on the masticatory performance (MP) of RPDs. Conclusion Subjective evaluation displays higher positive impact of RPDs in MP than objective evaluation. Assessment of patients' perspectives is important in clinical decision making. Multiple factors affect the MP with RPD treatment.

The mechanical properties of 3D printed denture base resin incorporating essential oil microcapsules.

Purpose: The aim of this study was to investigate the mechanical properties of three-dimensional (3D) printed denture base resin incorporating microcapsules containing plant essential oils. Materials and Methods: Denture base specimens containing up to 3% w/v essential oil microcapsule powders (MCPs), i.e., eucalyptus, geranium, lavender, menthol, and tea tree, in two resins (Detax and NextDent 3D+) were 3D printed using two printers (Asiga and NextDent 5100). The dispersion and interaction of the MCPs in the resin were assessed by SEM while the mechanical properties of the incorporated denture base including flexural strength (MPa), flexural modulus (MPa), Vickers hardness (VHN), and surface roughness (Ra) were also subsequently evaluated. Statistical analysis of any differences in mean values was determined using a two-way ANOVA with Tukey's post hoc testing (α = .05). Results: The spherical shape of the MCPs was maintained during the mixing and polymerization/printing process. However, the Detax-Asiga group showed significant agglomeration of the MCPs even at the lowest MCP concentration levels (0.5% w/v). Overall, as the microcapsule concentration increased, the mean flexural strength decreased, though the menthol MCP groups remained compliant with the ISO standard. The flexural modulus and harness remained relatively unchanged, and the flexural modulus complied with the ISO standard regardless of the MCP concentration. Surface roughness increased with the addition of the MCPs but also remained below that required for clinical acceptance. Conclusion: Incorporation of microencapsulated plant essential oils into 3D printed denture base resin was successfully achieved. While incorporation negatively influenced flexural strength and surface roughness, little effect on flexural modulus and Vickers hardness was demonstrated.

Material extrusion of thermoplastic acrylic for intraoral devices: Technical feasibility and evaluation.

With global demand for 3D printed medical devices on the rise, the search for safer, inexpensive, and sustainable methods is timely. Herein, we assessed the practicality of the material extrusion process for acrylic denture bases of which successful outcomes can be extended to implant surgical guides, orthodontic splints, impression trays, record bases and obturators for cleft palates or other maxillary defects. Representative materials comprising denture prototypes and test samples were designed and built with in-house polymethylmethacrylate filaments using varying print directions (PDs), layer heights (LHs) and reinforcements (RFs) with short glass fiber. The study undertook a comprehensive evaluation of the materials to determine their flexural, fracture, and thermal properties. Additional analyses for tensile and compressive properties, chemical composition, residual monomer, and surface roughness (Ra) were completed for parts with optimum parameters. Micrographic analysis of the acrylic composites revealed adequate fiber-matrix compatibility and predictably, their mechanical properties improved simultaneously with RFs and decreased LHs. Fiber reinforcement also improved the overall thermal conductivity of the materials. Ra, on the other hand, improved visibly with decreased RFs and LHs and the prototypes were effortlessly polished and characterized with veneering composites to mimic gingival tissues. In terms of chemical stability, the residual methyl methacrylate monomer contents are well below standards threshold for biological reactions. Notably, 5 vol% acrylic composites built with 0.05 mm LH in 0° on z-axis produced optimum properties that are superior to those of conventional acrylic, milled acrylic and 3D printed photopolymers. Finite element modeling successfully replicated the tensile properties of the prototypes. It may well be argued that the material extrusion process is cost-effective; however, the speed of manufacturing could be longer than that of established methods. Although the mean Ra is within an acceptable range, mandatory manual finishing and aesthetic pigmentation are required for long-term intraoral use. At a proof-of-concept level, it is evident that the material extrusion process can be applied to build inexpensive, safe, and robust thermoplastic acrylic devices. The broad outcomes of this novel study are equally worthy of academic reflection, and further translation to the clinic.

Medication-related osteonecrosis of the jaw: A disease of significant importance for older patients.

BACKGROUND: Medication-related osteonecrosis of the jaw (MRONJ) is clinically defined as a non-healing jawbone ulcerative-necrotic lesion appearing after dental therapy or minor trauma in patients treated previously with anti-resorptive, anti-angiogenic or immunomodulators. Older patients with osteoporosis and cancer receive these pharmacological agents regularly. As these patients are long-term survivors, efficient treatment is of paramount importance for their quality of life. METHODS: Literature searches via PubMed were conducted to identify relevant MRONJ studies. Basic information on MRONJ classification, clinical features, and pathosphysiology is presented herein as well as various clinical studies dealing with MRONJ in patients with osteoporosis and cancer. Lastly, we discuss current managment of patients and new trends in treatment of MRONJ. RESULTS: Although close follow-up and local hygiene have been advocated by some authors, severe forms of MRONJ are not responsive to conservative therapy. At present, there is no "gold standard" therapy for this condition. However, as the physiopathological basis of MRONJ is represented by the anti-angiogenic action of various pharmacological agents, new methods to increase and promote local angiogenesis and vascularization have recently been successfully tested in vitro, limited preclinical studies, and in a pilot clinical study. CONCLUSIONS: It appears that the best method implies application on the lesion of endothelial progenitor cells as well as pro-angiogenic factors such as Vascular Endothelial Growth Factor (VEGF) and other related molecules. More recently, scaffolds in which these factors have been incorporated have shown positive results in limited trials. However, these studies must be replicated to include a large number of cases before any official therapeutic protocol is adopted.

A 3-year qualitative evaluation of interprofessional team-based clinical education at an Australian dental school.

PURPOSE/OBJECTIVES: This article describes a qualitative evaluation of interprofessional (IP) team-based treatment planning (TBTP) involving dentistry, oral health therapy, dental prosthetics, and dental technology students at the Griffith University School of Dentistry and Oral Health (DOH). Using the same data from a recently published article that looked solely at the quantitative evaluation of TBTP, this article focuses on the qualitative evaluation of TBTP. This evaluation explores the contextual meaning related to the previously published aspects of TBTP that contributed positively toward oral health students' IP clinical learning and identifies themes reflecting students' IP clinical experience. METHODS: Thematic analysis of transcripts from nine focus groups, comprised of 46 final year students and open-ended questions collected from 544 students through an online instrument from 2012 to 2014, explored the question: "What is the contribution of IP student team-based processes on students' perceptions of IP learning and practice at DOH?" RESULTS: Responses from online participants and student focus groups revealed three major themes: useful role learning, communication confidence, and pro-active collaborative teamwork. Throughout each of these themes, students stated they possessed a confidence in collaborating with other oral health students as exhibited through an understanding of profession-specific and IP roles, self-assurance in communicating, and teamwork skills. CONCLUSION: Aspects of TBTP that contributed positively toward students' IP clinical learning and practice were meaningfully identified.

Overview of incorporation of inorganic antimicrobial materials in denture base resin: A scoping review.

STATEMENT OF PROBLEM: Dental hygiene for institutionalized patients and recurring Candida-associated denture stomatitis remain problematic because of a patient's limited dexterity or inability to eliminate Candida from denture surfaces. Although there has been extensive research into antimicrobial modification of denture base resins with inorganic materials, scoping reviews of the literature to identify knowledge gaps or efficacy of inorganic antimicrobial materials in denture base resins are lacking. PURPOSE: The purpose of this scoping review was to provide a synopsis of the efficacy of the major classes of inorganic antimicrobial materials currently incorporated into denture base resins. MATERIAL AND METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews was applied. Four electronic databases, including Embase, PubMed, Web of Science, and Google Scholar, were accessed for articles in the English language, up to February 2019, without restrictions on the date of publication. RESULTS: From the 53 articles selected, 25 distinguishable inorganic materials were found and divided into 3 subgroups. Forty-three articles evaluated nanomaterials, where mostly silver ion nanoparticles and/or titanium dioxide nanoparticles were incorporated into denture base resins. Fourteen articles examined antimicrobial drugs and medications, including azole group medications, amphotericin-B, Bactekiller, chlorhexidine, Novaron, and Zeomic. Two articles classified as others explored hydroxyapatite- and fiber-incorporated denture base resins. CONCLUSIONS: Although nanotechnology and antimicrobial medications or drugs have been successfully used to reduce Candida-associated denture stomatitis, long-term solutions are still lacking, and their disadvantages continue to outweigh their advantages.

Microbial Analysis of Obturators During Maxillofacial Prosthodontic Treatment Over an 8-Year Period.

The aim of the study was to investigate the microbial colonization (by Candida species, anaerobic and facultative anaerobic bacteria) of maxillary obturators used for the restoration of maxillary defects, including during radiotherapy.Retrospective cohort study.Fifteen patients requiring a maxillary obturator prosthesis had swabs of their obturators and adjacent tissues taken at different stages of their treatment over a period of 8 years.Identification of microbial species from the swabs was carried out using randomly amplified polymorphic DNA polymerase chain reaction (RAPD PCR) analysis, checkerboard DNA-DNA hybridization, CHROMagar Candida chromogenic agar, and DNA sequencing.Candida species were detected in all patients and all patients developed mucositis and candidiasis during radiotherapy which was associated with an increase in colonization of surfaces with Candida spp., particularly C albicans. Microbial colonization increased during radiotherapy and as an obturator aged, and decreased following a reline, delivery of a new prosthesis, or antifungal treatment during radiotherapy.Microbial colonization of maxillary obturators was related to the stage of treatment, age of the obturator material, radiotherapy and antifungal medications, and antifungal treatment may be recommended if C albicans colonization of palatal tissues is greater than 105 colony-forming units per cm2 following the first week of radiotherapy.

Sphericity of Periapical Lesion and Its Relation to the Novel CBCT Periapical Volume Index.

BACKGROUND: The purpose of this study was to assess the sphericity of periapical lesions and its relation to the cone-beam computed tomography periapical volume index (CBCTPAVI). METHODS: A total of 261 periapical lesions were assessed using cone-beam computed tomography images from InteleViewer. Three-dimensional analysis of the lesions was conducted using analytical imaging software Mimics Research. Lesion volume and surface area measurements were determined using the semiautomatic segmentation technique, and these measurements were then used to determine lesion sphericity and CBCTPAVI score. One-way analysis of variance with post hoc Tukey test was used to assess for differences in sphericity among CBCTPAVI groups. RESULTS: The mean sphericity of periapical lesions was 62%. Periapical lesions with larger CBCTPAVI scores were significantly less spherical than lesions with smaller CBCTPAVI scores. CONCLUSIONS: Periapical lesions of endodontic origin are mostly semi-spherical in their spread, and as CBCTPAVI score increases, sphericity decreases, indicating that larger lesions expand less uniformly compared with smaller lesions. Clinicians should be aware that lesions of increased volume have less sphericity, and are thus elongated or stretched in 1 or more anatomic plane. This information will assist clinicians in planning and performing periapical surgery and may aid in differential diagnosis of radiolucent jaw lesions.

Effectiveness of photobiomodulation in reducing pain and producing dental analgesia: a systematic review.

PURPOSE: Photobiomodulation (PBM) is reported in many studies to produce dental analgesia without producing thermal damage to tissues. This systematic review aims to assess in vivo studies to support the statement that PBM can produce dental analgesia. METHOD: A systematic search strategy was constructed, and PubMed, Scopus, and Embase databases were searched. Subsequently, inclusion and exclusion criteria were applied, reference lists were scanned, and hand searched to identify other suitable studies. RESULTS: Five studies met the inclusion criteria. Meta-analysis was not undertaken due to the heterogenous nature of the studies and data. Positive analgesia outcome was obtained in four out of five studies, and one study with no significant results was criticized for poor reporting of laser parameters, small sample size (six). CONCLUSION: In general, all studies were criticized for poor discussion of all covariates that could have modified the results, consequently resulting in poor quality of evidence, moderate risk of bias, and poor internal validity, as well as external validity. The systematic review also discussed the potential implications of all variables to be considered for future trials, including pulsing mode, contact modes, and tooth characteristics.

Trueness assessment of additively manufactured maxillary complete denture bases produced at different orientations.

STATEMENT OF PROBLEM: The trueness of the intaglio surface of an additively manufactured maxillary denture base may be influenced by the build orientation and the inclusion of support struts. PURPOSE: The purpose of this in vitro study was to compare the trueness of a photopolymer additively manufactured maxillary complete denture base created at different orientations with different support strut designs. Optimizing the build is critical for adopting best practice when fabricating maxillary complete dentures through additive manufacturing techniques. MATERIAL AND METHODS: Denture bases (N=70) were additively manufactured at 5 different build orientations (0-, 15-, 45-, 60-, and 90-degrees) with 10 specimens per orientation. Another 2 groups of 10 were manufactured by using the optimal printing orientation with and without support struts. The denture bases were scanned after storage in artificial saliva at 37 °C, and the scan data were analyzed with a 3D metrology software program. Statistical differences were determined with 1-way analysis of variance (ANOVA) and the Kruskal-Wallis test (α=.05). Color deviation heat maps were used to determine areas of clinically significant dimensional errors. RESULTS: Significant differences were found among groups for positive mean deviation (F=44.09, P<.001), negative mean deviation (F=11.69, P<.001), and root mean square deviation (F=17.11, P<.001) for the different orientations. One-way ANOVA revealed significant differences with the use of support struts in relation to negative mean deviation (F=3.857, P<.001) and RMSE (F=11.215, P<.001) and positive mean deviation (Kruskal-Wallis H=0.070, P=.007). The color deviation maps showed that a 45- to 90-degree print orientation was truest overall and that the addition of support struts to the cameo and intaglio surfaces improved the trueness of the maxillary denture bases. CONCLUSIONS: The build orientation and inclusion of support struts influenced the accuracy of the intaglio surface of additively manufactured maxillary denture bases. A 45- to 90-degree build orientation with support struts on the cameo and intaglio surfaces resulted in the truest denture base.

A 3-year quantitative evaluation of interprofessional team-based clinical education at an Australian dental school.

PURPOSE/OBJECTIVES: Clinical educational challenges led to the Griffith University School of Dentistry and Oral Health (DOH) introducing interprofessional team-based treatment planning (TBTP). This paper evaluates the interprofessional contribution made to student clinical learning and experience among dentistry, oral health therapy, dental prosthetics, and dental technology students. METHODS: A mixed methodology approach targeting 845 students collected data annually employing a prevalidated online instrument from 2012 to 2014 to answer the question: "What is the contribution of interprofessional student team-based processes on students' perceptions of interprofessional practice at DOH?" RESULTS: A representative study sample with a 64.4% response rate (N = 544) reported TBTP creating a supportive environment for interprofessional clinical learning. Significant improvements in learning shared across disciplines indicated improvements in mutual respect, understanding roles, and constructive communication enhancing teamwork. There were increasing significant correlations between shared learning and positive clinical experiences from 2012 (r = .642, p < .000) to 2013 (r = .678, p < .000) and 2014 (r = .719, p < .000). A combination of TBTP predictors accounted for 53% of the variance in clinical learning and experience in 2014 compared to 40% in 2012. CONCLUSION: Learning with other students, developing teamwork abilities, improved communication skills, and respect for other oral health professions were aspects of TBTP that positively impacted clinical learning and practice at DOH. Further study would assist to determine specific elements that made the greatest contribution to student learning experiences.

Root Canal Microbiome Associated With Asymptomatic Apical Periodontitis as Determined by High-Throughput Sequencing.

INTRODUCTION: Advanced DNA sequencing technology allows more detailed analysis and description of the endodontic microbiome. This study used the MiSeq high-throughput sequencing platform (Illumina, San Diego, CA) to describe the endodontic microbiome of teeth with primary asymptomatic apical periodontitis with no sinus tract. METHODS: Root canal samples from 25 patients were prepared for DNA sequencing analysis. Bacterial diversity of the microbiome was identified and compared between cases and according to the size of the related apical periodontitis lesions. Statistical analyses of the operational taxonomic unit distribution was performed using principal component analysis with the Bray-Curtis distance and a principal coordinate analysis, 2-way permutational multivariate analysis of variance. The chi-square or Fisher exact test was used to evaluate the prevalence of different operational taxonomic units related to small and large apical periodontitis lesions. RESULTS: Although there was a very high bacterial diversity in the microbiome of teeth with asymptomatic apical periodontitis, 4 phyla dominated the microbiome: Firmicutes (27%), Bacteroidetes (21%), Proteobacteria (21%), and Actinobacteria (12%). There was high variability in species composition between root canal samples with no common species pattern for the cases. Large lesions showed a higher number of species but did not significantly differ from small lesions in bacterial diversity indexes. Bacteroidaceae [G-1] bacterium HMT 272, a previously uncultivated but still unnamed and uncharacterized taxon, was the most prevalent and abundant phylotype. CONCLUSIONS: High-throughput sequencing technology confirmed the complexity of the endodontic microbiome and revealed that microbial heterogeneity is a feature between cases. This indicates that various microbial combinations of the endodontic microbiome are able to illicit periapical inflammatory diseases.