The effect of food medium on the wear behaviour of veneering porcelain: An in vitro study using the three-body abrasion mode.

Objectives: The present study examined the effect of food medium on the three-body wear behaviour of veneering porcelain derived from porcelain-fused-to-metal crowns.

Methods: Seventy-four rectangular metal-ceramic specimens were prepared using Ceramco III as the veneering porcelain. After storage in distilled water at 37 °C for 2 days, the specimens were tested with a custom-designed chewing machine with a stainless steel ball as antagonist (350 N loads, 2.

Management of Large Radicular Lesions Using Decompression: A Case Series and Review of the Literature.

The purpose of this study was to report the clinical efficacy of decompression for 3 cases with large periapical lesions and to review technique details. Three cases with large periapical cystic lesions were treated with decompression after root canal treatment. A traditional decompression technique was used for the first case.

Recent progress in the industrial and biomedical applications of tragacanth gum: A review.

Natural polymers have distinct advantages over synthetic polymers because of their abundance, biocompatibility, and biodegradability. Tragacanth gum, an anionic polysaccharide, is a natural polymer which is derived from renewable sources. As a biomaterial, tragacanth gum has been used in industrial settings such as food packaging and water treatment, as well as in the biomedical field as drug carriers and for wound healing purposes.

Carbodiimide inactivation of matrix metalloproteinases in radicular dentine.

Objectives: The present in vitro study evaluated the effect of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), a cross-linking agent used as an additional therapeutic primer for luting fiber posts to radicular dentine to prevent hybrid layer degradation.

Methods: Root canal treatment was performed on 80 extracted single-rooted human teeth. A 10-mm post space was prepared and pecimens were randomly assigned to four groups (n=20) according to the bonding system: 1) All Bond 3 (Bisco); 2) All Bond 3 + 0.

Postprocessing of all-zirconia restorations in digital dental radiographs: a quality assurance predicament.

Objectives: The aim of this study was to describe a quality assurance issue, that is, the production of nondiagnostic high-contrast radiographs when imaging teeth restored with all-zirconia crowns on bitewing radiographs.

Study Design: All-zirconia crowns were imaged with DIGORA Optime photostimulable phosphor (PSP) plates (Soredex/Orion Corp., Helsinki, Finland).

Bimodal antibacterial system based on quaternary ammonium silane-coupled core-shell hollow mesoporous silica.

Hollow mesoporous silica (HMS) have been extensively investigated as a biomaterial for drug delivery. The present study developed quaternary ammonium silane-grafted hollow mesoporous silica (QHMS) to create a metronidazole (MDZ) sustained delivery system, MDZ@QHMS, with bimodal, contact-kill and release-kill capability. The QHMS was assembled through a self-templating method.

Novel Biomedical Applications of Crosslinked Collagen.

Collagen is one of the most useful biopolymers because of its low immunogenicity and biocompatibility. The biomedical potential of natural collagen is limited by its poor mechanical strength, thermal stability, and enzyme resistance, but exogenous chemical, physical, or biological crosslinks have been used to modify the molecular structure of collagen to minimize degradation and enhance mechanical stability. Although crosslinked collagen-based materials have been widely used in biomedicine, there is no standard crosslinking protocol that can achieve a perfect balance between stability and functional remodeling of collagen.

Isocyanate-terminated urethane-based dental adhesive bridges dentinal matrix collagen with adhesive resin.

Commercially available dental adhesives fail to chemically unite the demineralized collagen matrix with resinous materials within the resin-dentin interface. Sub-micron separations between the collagen fibrils and polymerized resin provide the backdrop for bond deterioration. Here, novel isocyanate-terminated urethane methacrylate precursors (UMP) were synthesized with the capacity to bond chemically to dentin collagen via covalent and hydrogen bonds.

Associations among Bruxism, Gastroesophageal Reflux Disease, and Tooth Wear.

The relationship between bruxism and tooth wear is contentious in the literature. The pathophysiological processes of tooth wear may be complicated by the relationship between bruxism and gastroesophageal reflux disease (GERD). The objective of this study was to evaluate the associations among bruxism, GERD, and tooth wear.

Biochemical and immunohistochemical identification of MMP-7 in human dentin.

Objectives: Matrix metalloproteinases (MMPs) are dentinal endogenous enzymes claimed to have a vital role in dentin organic matrix breakdown. The aim of the study was to investigate presence, localization and distribution of MMP-7 in sound human dentin.

Methods: Dentin was powdered, demineralized and dissolved in isoelectric focusing buffer.

Contribution of Mitophagy to Cell-Mediated Mineralization: Revisiting a 50-Year-Old Conundrum.

Biomineralization in vertebrates is initiated via amorphous calcium phosphate (ACP) precursors. These precursors infiltrate the extracellular collagen matrix where they undergo phase transformation into intrafibrillar carbonated apatite. Although it is well established that ACP precursors are released from intracellular vesicles through exocytosis, an unsolved enigma in this cell-mediated mineralization process is how ACP precursors, initially produced in the mitochondria, are translocated to the intracellular vesicles.

Quaternary ammonium silane-based antibacterial and anti-proteolytic cavity cleanser.

Objective: Secondary caries and degradation of hybrid layers are two major challenges in achieving durable resin-dentin bonds. The objectives of the present study were to investigate the effects of a 2% quaternary ammonium silane (QAS) cavity cleanser on bacteria impregnated into dentin blocks and the gelatinolytic activity of the hybrid layers.

Methods: Microtensile bond strength was first performed to evaluate if the 2% QAS cavity cleanser adversely affected bond strength.

Chitosan-Based Extrafibrillar Demineralization for Dentin Bonding.

Instability of resin-dentin bonds is the Achilles' heel of adhesive dentistry. To address this problem, a chelate-and-rinse extrafibrillar dentin demineralization strategy has been developed that keeps intrafibrillar minerals within collagen fibrils intact to prevent activation of endogenous proteases that are responsible for collagen degradation within hybrid layers. The objective of the present study was to evaluate the potential of using chitosan >40 kDa as an antimicrobial extrafibrillar dentin-chelating agent to enhance bond durability.

Anti-biofilm efficacy of root canal irrigants against in-situ Enterococcus faecalis biofilms in root canals, isthmuses and dentinal tubules.

Objective: To investigate the anti-biofilm efficacy of root canal irrigants in canal spaces, isthmi and dentinal tubules of root canals ex vivo.

Methods: Fifty-one single-rooted premolars, each containing an isthmus, were instrumented, autoclaved and inoculated with Enterococcus faecalis for 4 weeks. One specimen was sectioned for bacteria-specific staining to confirm the presence of biofilms using light microscopiy.

Effect of simulated intraosseous sinusoidal pressure on NaOCl extrusion.

Introduction: The present study examined the effects of irrigant flow rate and simulated intraosseous sinusoidal pressure on the rate of NaOCl extrusion from the apical terminus of a faux root canal.

Methods: An extrusion setup was designed to enable irrigant extrusion to be opposed by 30 mm Hg simulated intraosseous pressure. The faux canal apex was opposed by atmospheric + 30 mm Hg pressure (experimental) or atmospheric pressure only (control group).

Association between bruxism and symptomatic gastroesophageal reflux disease: A case-control study.

Objectives: To examine the relation between bruxism and gastroesophageal reflux disease (GERD) and the contribution of depression, anxiety and impaired sleep quality to that association.

Methods: A three-centre case-control study was conducted consisting of 887 consecutive clinically-diagnosed bruxism patients aged 18-75 years and 887 matched controls. Diagnosis of GERD was based on the Montreal definition: moderate/severe symptoms ≥ one day/week or mild symptoms ≥ two days/week.

From manual periodontal probing to digital 3-D imaging to endoscopic capillaroscopy: Recent advances in periodontal disease diagnosis.

Deepened periodontal pockets exert a significant pathological burden on the host and its immune system, particularly in a patient with generalized moderate to severe periodontitis. This burden is extensive and longitudinal, occurring over decades of disease development. Considerable diagnostic and prognostic successes in this regard have come from efforts to measure the depths of the pockets and their contents, including level of inflammatory mediators, cellular exudates and microbes; however, the current standard of care for measuring these pockets, periodontal probing, is an analog technology in a digital age.

Antibacterial efficacy of an endodontic sonic-powered irrigation system: An in vitro study.

Objective: To evaluate the efficacy of EDDY, a new sonic-powered irrigation system, in reducing intracanal bacteria load.

Methods: Thirty-eight instrumented, autoclaved single-rooted human premolars were inoculated with Enterococcus faecalis (ATCC-29212) for 21 days. Two teeth were used as negative control without bacterial contamination.

Optimizing resin-dentin bond stability using a bioactive adhesive with concomitant antibacterial properties and anti-proteolytic activities.

Unlabelled: Secondary caries and hybrid layer degradation are two major challenges encountered in long-term resin-dentin bond stability. As a link between resin and dentin, adhesives that possess both antimicrobial and anti-proteolytic activities are in demand for eliminating bacteria-induced secondary caries and preventing hybrid layers from degradation. In the present study, a new quaternary ammonium methacryloxy silane (QAMS) prepared from sol-gel chemistry was incorporated into experimental adhesives to examine their antimicrobial effect and anti-proteolytic potential.

Biological Activities and Potential Oral Applications of N-Acetylcysteine: Progress and Prospects.

N-Acetylcysteine (NAC), a cysteine prodrug and glutathione (GSH) precursor, has been used for several decades in clinical therapeutic practices as a mucolytic agent and for the treatment of disorders associated with GSH deficiency. Other therapeutic activities of NAC include inhibition of inflammation/NF-B signaling and expression of proinflammatory cytokines. N-Acetylcysteine is also a nonantibiotic compound possessing antimicrobial property and exerts anticarcinogenic and antimutagenic effects against certain types of cancer.

The Photoshop Smile Design Technique.

Esthetic or cosmetic dentistry has become one of the main areas of dental practice emphasis and growth for the past several decades. Many articles have been written and courses taught over the years on concepts of smile design to develop a treatment plan for an esthetic outcome for the patient. The beauty of digital smile design is that patients can see the potential esthetic outcomes of treatment options in minutes.

Microbiologic effect of two topical anti-infective treatments on ligature-induced peri-implantitis: A pilot study in dogs.

Background: The aim of this split-mouth design pilot study in dogs was to assess microbiologic effects of two topical anti-infective treatment protocols on dental implants subjected to ligature-induced peri-implantitis, without use of systemic antibiotics.

Methods: Eight adult Beagle dogs each received four dental implants in contralateral, edentulated, mandibular jaw quadrants. After 8 weeks, silk ligatures were installed, to be removed after another 8 weeks.

Water-associated attributes in the contemporary dentin bonding milieu.

Objectives: The water-associated attributes of resin-dentin interfaces created by contemporary adhesives are important determinants of bond integrity and stability. In the present work, these attributes were estimated from the perspectives of causality, to examine the behavior of the first and most-recently launched versions of universal adhesives when applied in either the etch-and-rinse mode or the self-etch mode.

Methods: The immediate cause of interfacial permeability and the time-dependent cause of water sorption were investigated in conjunction with the intermediate effect of interface degradation and the more long-term effect of loss of mechanical strength, before and after thermomechanical cycling.

Changes in the radicular pulp-dentine complex in healthy intact teeth and in response to deep caries or restorations: A histological and histobacteriological study.

Introduction: The present study reported the histological events that occurred in the radicular pulp of human mature teeth in the presence of medium/deep untreated caries lesions, and those teeth with restorations or direct pulp capping, with particular emphasis on the morphology of the canal wall dentine and the odontoblast layer.

Methods: Sixty-two teeth with medium/deep caries lesions, extensive restorations or after application of a direct pulp capping procedure were obtained from 57 subjects. Fourteen intact mature teeth served as controls.