Positive ethics and dental students.

Recent negative publicity has drawn attention away from recognizing and celebrating the ways today's dental students differ in a positive fashion from previous generations of dental students who may have suffered the same ethical lapses we are hearing about now. Dental students are more diverse than their predecessors and learn to develop a sense of integrity that encompasses more toleration of alternative cultures. They are group-oriented, which expresses itself in sharing responsibility for their colleagues, both in educational settings and in their practices.

Biglycan overexpression on tooth enamel formation in transgenic mice.

Previously, it was shown that the volume of forming enamel of molar teeth in biglycan-null mice was greater than that in genetically matched wild-type mice. This phenotypic change appeared to result from an increase in amelogenin expression, implying that biglycan directly influences amelogenin synthesis. To determine whether biglycan overexpression resulted in decreased amelogenin expression, we engineered transgenic mice to overexpress biglycan in the enamel organ epithelium.

Pharmacologic stem cell based intervention as a new approach to osteoporosis treatment in rodents.

Background: Osteoporosis is the most prevalent skeletal disorder, characterized by a low bone mineral density (BMD) and bone structural deterioration, leading to bone fragility fractures. Accelerated bone resorption by osteoclasts has been established as a principal mechanism in osteoporosis. However, recent experimental evidences suggest that inappropriate apoptosis of osteoblasts/osteocytes accounts for, at least in part, the imbalance in bone remodeling as occurs in osteoporosis.

Measuring salivary flow: challenges and opportunities.

Background: Saliva is being studied extensively and is being used for risk assessment, diagnosis and monitoring high-risk behavior and disease progression. A variety of medical conditions and medications are associated with salivary gland hypofunction. The major disadvantage in the use of saliva for health-related purposes is the lack of standardization in saliva collection methods.

Clinically based diagnostic wax-up for optimal esthetics: the diagnostic mock-up.

A diagnostic wax-up can enhance the predictability of treatment by modeling the desired result in wax prior to treatment. It is critical to correlate the wax-up to the patient to avoid a result that appears optimal on the casts but does not correspond to the patient's smile. This article reviews the applications and techniques for clinically based diagnostic wax-up, and focuses on the diagnostic mock-up philosophy as a means to obtain predictable esthetics and function.

Periodontally accelerated osteogenic orthodontics combined with autogenous bone grafting.

This case report documents the first use of particulate autogenous bone graft with the corticotomy-assisted rapid orthodontic procedure known as periodontally accelerated osteogenic orthodontics (PAOO). A 41-year-old man, with class II, division 2 crowded occlusion, was treated with the PAOO procedure. Buccal mucoperiosteal flaps were reflected, and selected vertical and horizontal corticotomy was performed around the roots in both the maxillary and mandibular arches.

Clinical and microbiological determinants of ailing dental implants.

Background: The failure of the host tissue to establish or maintain osseointegration around dental implants is due to either occlusal or parafunctional forces, premature loading, ill-directed stress, or microbial infection. The long-term failure rate of dental implants is generally 5-10%. Although a variety of etiologies of early peri-implant bone loss (from implant placement to 1-year post-loading) have been proposed, factors associated with late implant failures are less well understood but are probably related to both the peri-implant microbial environment and host factors.

Direct dentin bonding technique sensitivity when using air/suction drying steps.

Statement Of Problem: Moisture control before and after application of the primer/adhesive components of etch-and-rinse dentin bonding agents is usually achieved using a stream of air delivered by an air syringe. Suction drying with a suction tip is a common alternative for moisture control, but data about the use of suction drying instead of the air syringe is scarce or nonexistent.

Purpose: The purpose of this study was to compare the dentin microtensile bond strength (MTBS) using either the air syringe or the suction tip to control the amount of moisture.

SloR modulation of the Streptococcus mutans acid tolerance response involves the GcrR response regulator as an essential intermediary.

Streptococcus mutans, the primary causative agent of human dental caries, grows as a biofilm on the tooth surface, where it metabolizes dietary carbohydrates and generates acid byproducts that demineralize tooth enamel. A drop in plaque pH stimulates an adaptive acid-tolerance response (ATR) in this oral pathogen that allows it to survive acid challenge at pHs as low as 3.0.

Immunology, microbiology, and virology following placement of NobelPerfect scalloped dental implants: analysis of a case series.

Background: Cytokine-microbiology-virology monitoring after implant placement may help to develop profiles of variables that can help to explain interaction between the immune system and alveolar bone. Descriptive information at the molecular and cellular levels after implant placement is important in the emerging field of osteoimmunology and may help to formulate hypotheses and intervention strategies in periodontology and implantology.

Purpose: The purpose of this study was to determine the presence or absence of selected cytokines in association with periodontopathogens and human cytomegalovirus (HCMV) after placement of dental implants.

Microbiology and cytokine levels around healthy dental implants and teeth.

Background: Elicitation of the relationship of periodontopathogens and pro-inflammatory cytokines to bone resorption and formation is significant to a growing body of research known as osteoimmunology. It is essential that clinically healthy peri-implant and periodontal sites are studied to contribute comparison data for investigations that are addressing diseased sites.

Purpose: The purpose of this study was to describe levels of selected pro-inflammatory cytokines in clinically healthy peri-implant and periodontal sites, and to examine whether cytokine levels may be related to specific bacterial/viral pathogens.

Characterization of the apical papilla and its residing stem cells from human immature permanent teeth: a pilot study.

Mesenchymal stem cells (MSCs) have been isolated from the pulp tissue of permanent teeth (dental pulp stem cells or DPSCs) and deciduous teeth (stem cells from human exfoliated deciduous teeth). We recently discovered another type of MSCs in the apical papilla of human immature permanent teeth termed stem cells from the apical papilla (SCAP). Here, we further characterized the apical papilla tissue and stem cell properties of SCAP using histologic, immunohistochemical, and immunocytofluorescent analyses.

PBL Core Skills Faculty Development Workshop 3: understanding PBL process assessment and feedback via scenario-based discussions, observation, and role-play.

Tutorial assessment in PBL is thought to be a valid assessment approach and is believed to exert a positive impact on the learning process. Reports, however, have demonstrated that assessment by the facilitator can be unreliable. Training of faculty to conduct this type of assessment has tended to be lacking and is a likely contributor to this inconsistency.

Leucine-rich amelogenin peptide induces osteogenesis in mouse embryonic stem cells.

Leucine-rich amelogenin peptide (LRAP), an alternatively spliced amelogenin protein, possesses a signaling property shown to induce osteogenic differentiation. In the current study, we detected LRAP expression during osteogenesis of wild-type (WT) embryonic stem (ES) cells and observed the absence of LRAP expression in amelogenin-null (KO) ES cells. We explored the signaling effect of LRAP on wild-type ES cells, and the ability of LRAP to rescue the impaired osteogenesis phenotype observed in KO ES cells.

Fabrication of an all-ceramic abutment crown under an existing removable partial denture using CAD/CAM technology.

Fabricating a crown beneath an existing removable partial denture is technique sensitive, difficult, and time consuming. A procedure is described using CAD/CAM technology to fabricate an all-ceramic crown under an existing removable partial denture that is simple, esthetic, and convenient for the patient and the clinician.

Perspectives on the 2007 AHA Endocarditis Prevention Guidelines.

From 2005 to 2007, the American Heart Association convened a consensus panel of experts to revisit the guidelines for the premedication of patients with cardiac defects prior to dental treatment. Presented in this article is a summary of the guidelines as well as commentary on the process.

Adhesive restorations, centric relation, and the Dahl principle: minimally invasive approaches to localized anterior tooth erosion.

The purpose of this article is to review biomechanical and occlusal principles that could help optimize the conservative treatment of severely eroded and worn anterior dentition using adhesive restorations. It appears that enamel and dentin bonding, through the combined use of resin composites (on the palatal surface) and indirect porcelain veneers (on the facial/incisal surfaces) can lead to an optimal result from both esthetic and functional/biomechanical aspects. Cases of deep bite combined with palatal erosion and wear can be particularly challenging.

Determination of protein regions responsible for interactions of amelogenin with CD63 and LAMP1.

The enamel matrix protein amelogenin is secreted by ameloblasts into the extracellular space to guide the formation of highly ordered hydroxyapatite mineral crystallites, and, subsequently, is almost completely removed during mineral maturation. Amelogenin interacts with the transmembrane proteins CD63 and LAMP (lysosome-associated membrane protein) 1, which are involved in endocytosis. Exogenously added amelogenin has been observed to move rapidly into CD63/LAMP1-positive vesicles in cultured cells.

Human Hertwig's epithelial root sheath cells play crucial roles in cementum formation.

Unlabelled: Hertwig's epithelial root sheath (HERS) cells are a unique population of epithelial cells in the periodontal ligament compartment. To date, their functional role has not been fully elucidated. Our hypothesis was that HERS cells may be involved in regulating differentiation of periodontal ligament stem cells (PDLSCs) and forming cementum in vivo.

Problem-based learning in undergraduate dental education: faculty development at the University of Southern California School of Dentistry.

The University of Southern California School of Dentistry (USCSD) seeks to educate oral health professionals with a balanced curriculum covering health promotion, risk assessment and disease prevention, diagnostics, treatments, and therapeutics. Based on critical analyses of a 5-year educational demonstration project, the USCSD proposed to use problem-based learning (PBL) to achieve its goals. Among the many changes required to convert a traditional dental educational curriculum to PBL, none is more important than that of faculty development.

The response regulator ComE in Streptococcus mutans functions both as a transcription activator of mutacin production and repressor of CSP biosynthesis.

In Streptococcus pneumoniae, competence and bacteriocin genes are controlled by two two-component systems, ComED and BlpRH, respectively. In Streptococcus mutans, both functions are controlled by the ComED system. Recent studies in S.

PBL core skills faculty development workshop 1: An experiential exercise with the PBL process.

This report describes the first in a series of foundation-building faculty development workshops focused on the instructional methodology of problem-based learning (PBL). The PBL Process workshop reported here introduced the learning theory topics supporting PBL and utilized an extended roleplay method to provide participants with personal experience with the PBL learning cycle. Overall, participants were satisfied with the methods and content of the workshop.