LRP5 and bone mass regulation: Where are we now?

The discovery of causal mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene underlying conditions of altered bone mass ushered in a new era in bone research. Since those original publications, the role of Lrp5 and the Wnt/β-catenin signaling pathway controlled by Lrp5 and its homologs, Lrp6 and Lrp4, in bone mass regulation has been an intense area of investigation. Studies to date have implicated this pathway in skeletal development, osteoblast differentiation and proliferation, osteoblast/osteocyte apoptosis, regulation of the balance between osteogenesis-chondrogenesis-adipogenesis, regulation of osteoclastogenesis and the response of bone to mechanical loading.

Interproximal cervical lesions caused by incorrect flossing technique.

Unlabelled: This case report describes an interproximal cervical lesion caused by the incorrect use of dental floss. A 58-year-old man who was asymptomatic, presented with unusual notch-like cervical lesions. After clinical and radiographical examinations, it was concluded that the aetiology of these lesions was an incorrect flossing technique.

Activation of β-catenin signaling in MLO-Y4 osteocytic cells versus 2T3 osteoblastic cells by fluid flow shear stress and PGE2: Implications for the study of mechanosensation in bone.

The osteocyte is hypothesized to be the mechanosensory cell in bone. However, osteoblastic cell models have been most commonly used to investigate mechanisms of mechanosensation in bone. Therefore, we sought to determine if differences might exist between osteocytic and osteoblastic cell models relative to the activation of β-catenin signaling in MLO-Y4 osteocytic, 2T3 osteoblastic and primary neonatal calvarial cells (NCCs) in response to pulsatile fluid flow shear stress (PFFSS).

Efficacy of cone-beam computed tomography as a modality to accurately identify the presence of second mesiobuccal canals in maxillary first and second molars: a pilot study.

Introduction: The achievement of successful nonsurgical endodontic therapy relies on the location, disinfection, and obturation of all canals in the root canal system. This study evaluated the ability of the i-CAT cone-beam computed tomography (CBCT) unit (Imaging Sciences International, Hatfield, PA) to accurately identify the presence or absence of the second mesiobuccal canal (MB2) in maxillary first and maxillary second human molars.

Methods: Twenty completely intact maxillary first and second molars were used as test subjects.

Evidence-based practice of periodontics.

Evidence-based practice involves complex and conscientious decision making based not only on the available evidence but also on patient characteristics, situations, and preferences. It recognizes that care is individualized and ever-changing and involves uncertainties and probabilities. The specialty of periodontics has abundant high-level evidence upon which treatment decisions can be determined.

Articaine: a new alternative in dental hygiene pain control.

Purpose: Local anesthesia administration is integral to pain control in dental hygiene. As of 2006, 40 licensing jurisdictions in the United States include local anesthesia administration in the scope of dental hygiene practice. While the risks associated with use of intraoral local anesthesia are not great, careful attention to recommended practices helps foster patient safety.

Surface quality and long-term dimensional stability of current elastomeric impression materials after disinfection.

Purpose: The objectives of this investigation were to evaluate the effect of disinfection on surface quality and dimensional stability of more recent, reformulated vinylpolysiloxane (VPS) and polyether (PE) materials.

Methods: Using ANSI/American Dental Association (ADA) specification 19 protocols, 50 impressions of stainless steel dies were made with each material. Ten impressions of each material were randomly assigned to a treatment group: (1) no disinfectant; (2) 10-minute dual phenol immersion; (3) 1-hour dual phenol; (4) 10-minute sodium hypochlorite (NaOCl); and (5) 1-hour NaOCl.

Diseases of Wnt signaling.

The Wnt signaling pathways play fundamental roles in the differentiation, proliferation, death and function of many cells and as a result are involved in critical developmental, growth and homeostatic processes in animals. There are four currently known pathways of Wnt signaling; the so-called canonical or Wnt/beta-catenin pathway, the Wnt/Ca(+2) pathway involving Protein Kinase A, the planar cell polarity pathway and a pathway involving Protein Kinase C that functions in muscle myogenesis. The best studied of these is the Wnt/beta-catenin pathway.

New insights into extracellular matrix assembly and reorganization from dynamic imaging of extracellular matrix proteins in living osteoblasts.

The extracellular matrix (ECM) has been traditionally viewed as a static scaffold that supports cells and tissues. However, recent dynamic imaging studies suggest that ECM components are highly elastic and undergo continual movement and deformation. Latent transforming growth factor beta (TGFbeta) binding protein-1 (LTBP1) is an ECM glycoprotein that binds latent TGFbeta and regulates its availability and activity.

Sealing ability of three materials in the orifice of root canal systems obturated with gutta-percha.

There were 130 single roots randomly assigned to one of 12 experimental or two control groups. Forty specimens each were sealed with 1, 2, 3, or 4 mm of Cavit, ProRoot MTA, or Tetric. After creation of a uniform orifice diameter, the smear layer was removed and the canal systems obturated using warm lateral compaction of gutta-percha (GP).

Assessing interdisciplinary education in U.S. dental hygiene programs.

This study was done to examine the role of interdisciplinary education in dental hygiene curricula, identify factors associated with its implementation, explore the perceptions of dental hygiene educators related to interdisciplinary education, and explore these educators' perception of its validity and barriers to implementation. A 36-item questionnaire mailed to directors of all 216 dental hygiene programs in the United States elicited program demographics and information about participation in clinical and didactic interdisciplinary educational experience as well as attitudes regarding such experiences. The response rate was 63% (n = 136).

Influence of additional acid etch treatment on resin cement dentin infiltration.

Purpose: The purpose of this study was to compare the penetration of a resin cement into dentin surfaces pretreated with self-etching primer with or without conventional acid etch.

Materials And Methods: Dentin surfaces of 8 unerupted human third molars were treated with self-etch primer (Panavia 21; Kuraray Co, Ltd, Osaka, Japan) with or without conventional acid etch treatment. A resin cement (Panavia 21) was applied according to manufacturer's instructions.

Validity and reliability of the oral health-related quality of life instrument for dental hygiene.

Purpose: The purpose of this study was to examine reliability, construct validity, and produce a concise instrument for assessing Oral Health-Related Quality of Life (OHRQL).

Method: The OHRQL model for dental hygiene served as the theoretical basis in the development of this instrument. The survey utilized five-point Likert scale items, designed to assess the domains of symptom status, functional status, and health perceptions.

The effect of ultrasonics on sealer distribution and sealing of root canals.

The purpose of this study was to compare the ultrasonic and hand methods of sealer placement using three types of sealers: Sultan "Grossman's formula," AH-26, and CRCS. The effect of these methods on radiographic density, sealer distribution, and on the apical seal of the different sealers was evaluated. The in vitro experiment was carried out using human extracted mandibular incisors and mesio-buccal roots of maxillary first and second molars.

Effects of dentin age and bonding on microgap formation.

This study compared the effectiveness of dentin adhesives in extracted molars from younger (16-26) and older (58-87) human subjects. Extracted molars were selected to be restored with one of two dentin bonding agents (n = 22 per group). Opposite sides of each molar were ground flat and a 3 mm x 3 mm cylindrical preparation was milled into each surface.

Aerobic bacterial contamination in dental materials.

Current concern about disease transmission points out the need for better infection control in dentistry. The purpose of this study was to test samples of dental materials in factory-sealed containers for aerobic bacterial contamination. Multiple unopened containers of 12 different dental materials were obtained from the dental school dispensary.

Barrier techniques to infection: a national survey of pediatric dentists.

Pediatric dentists are at increasing risk of exposure to the human immunodeficiency virus (HIV). Therefore, a nationwide survey was conducted to describe pediatric dentists' use of barrier techniques and infection-control procedures and to identify factors that might impede their use. Questionnaires were mailed to a random sample of 1581 practicing pediatric dentists.

Developing population profiles from dental claims data for conceptualizing effectiveness of care.

The purpose of this study was to explore longitudinal observational analysis of insurance claims data with goal of graphically demonstrating that effective dental care leads to the diminished use of services in subsequent time intervals. Using the Rand HIE claims data, definitions of the best patients for whom claims data would be profiled and the best parameters to use in rate calculations for the time series graphs were empirically derived. Profiles using these definitions were found to be very similar to a conceptual model of such profiles.

Dentofacial trauma in children.

Most of the literature on dental injury pertains to the classification, incidence, prevalence, and treatment of fractured teeth. A major finding here is that the five leading causes of dentofacial injuries, regardless of severity, were falls, being struck by an object, bicycle accidents, assaults, and motor vehicle accidents.