Labial Reduction Guide for Laminate Veneer Preparation

This article describes a method of fabricating a labial reduction guide for laminate veneer preparations by using a digital tire tread depth gauge and orthodontic wire. The labial reduction guide can help clinicians to achieve accurate reduction of the labial surface. Minimally invasive porcelain laminate veneers have become a popular option in esthetic dentistry. Porcelain laminate veneers require only 25% to 50% of the amount of tooth reduction required for complete coverage restorations.Nevertheless, adequate labial reduction is important in creating optimal esthetics. However, excessive reduction can lead to compromised bond strength due to penetration of the enamel surface. Typically, the appropriate reduction is determined from a diagnostic waxing, and then a silicone index or thermoplastic matrix is made to guide preparation. Verifying the amount of reduction during tooth preparation from the guide can be problematic because the range of labial reduction for laminate veneers is small (0.3 to 0.9 mm). Freehand labial reduction can result in insufficient tooth removal.The purpose of this article was to describe the fabrication and use of a labial reduction guide (LRG) for laminate veneers

Custom Total Occlusal Convergence Angle Sticker Fabrication

This article describes a method of fabricating a custom total occlusal convergence angle sticker with photo editing software and label stickers. The custom total occlusal convergence angle sticker can help clinicians achieve an accurate degree of taper during axial wall reduction of tooth preparation

Sensory Competition in the Face Processing Areas of the Human Brain

The concurrent presentation of multiple stimuli in the visual field may trigger mutually suppressive interactions throughout the ventral visual stream. While several studies have been performed on sensory competition effects among non-face stimuli relatively little is known about the interactions in the human brain for multiple face stimuli. In the present study we analyzed the neuronal basis of sensory competition in an event-related functional magnetic resonance imaging (fMRI) study using multiple face stimuli. We varied the ratio of faces and phase-noise images within a composite display with a constant number of peripheral stimuli, thereby manipulating the competitive interactions between faces. For contralaterally presented stimuli we observed strong competition effects in the fusiform face area (FFA) bilaterally and in the right lateral occipital area (LOC), but not in the occipital face area (OFA), suggesting their different roles in sensory competition. When we increased the spatial distance among pairs of faces the magnitude of suppressive interactions was reduced in the FFA. Surprisingly, the magnitude of competition depended on the visual hemifield of the stimuli: ipsilateral stimulation reduced the competition effects somewhat in the right LOC while it increased them in the left LOC. This suggests a left hemifield dominance of sensory competition. Our results support the sensory competition theory in the processing of multiple faces and suggests that sensory competition occurs in several cortical areas in both cerebral hemispheres

The Post–endodontic Adhesive Interface: Theoretical Perspectives and Potential Flaws

Introduction The aim of this review was to analyze the potential of successful bonds of endodontic posts to radicular dentin as well as the limitations of the post–endodontic adhesive interface. Methods The MEDLINE/PubMed and Web of Science electronic databases were searched. The search was augmented by a manual search of the pertinent bibliographies. Results The post–endodontic adhesive interface finds application in the endodontic cohesive units. Many techniques and materials exist to improve the bond between endodontic posts and resin-based materials as well as between resin-based materials and radicular dentin. Different techniques used for the adhesion of metallic and fiber-reinforced posts are discussed and critically analyzed. Conclusions Although adhesive cementation of endodontic posts is popular, a long-term predictable bond may be compromised because of procedures related to the endodontic treatment and/or the adhesive cementation procedures. Microleakage and degradation phenomena may further jeopardize the post–endodontic adhesive interface

Fracture Resistance of Compromised Endodontically Treated Teeth Restored with Bonded Post and Cores: An in Vitro Study

Statement of problem: It is unclear which post and core system performs best when bonded to severely compromised endodontically treated teeth. Purpose: The purpose of this study was to investigate the fracture resistance and mode of failure of severely compromised teeth restored with 3 different adhesively bonded post and core systems. Material and methods: Thirty extracted endodontically treated maxillary anterior teeth were randomly divided into 3 groups, CPC, gold cast post and core; TPC, titanium prefabricated post/composite resin core; and FPC, quartz fiber reinforced post/composite resin core. All posts were adhesively cemented. All cores resembled a central incisor preparation with no remaining tooth structure above the finish line. Cast gold crowns were fabricated and cemented adhesively. The specimens were aged with thermocycling and cyclic loading. Two specimens per group were randomly selected for micro-computed tomographic imaging before and after aging. Failure was induced with a universal testing machine. The mode of failure was characterized by the interface separation. Data were analyzed with 1-way ANOVA (α=.05) followed by post hoc tests (Bonferroni). Results: A statistically significant difference was found among the 3 groups (P=.002). CPC was significantly different than TPC (P=.008) or FPC (P=.003). The primary mode of failure for CPC and TPC was root fracture, and for FPC post debonding. Conclusions: Severely compromised endodontically treated teeth restored with bonded gold cast post and cores showed significantly higher fracture resistance

Agglutinated foraminifera from neritic to bathyal facies in the Palaeogene of Spitsbergen and the Barents Sea

Late Palaeocene to Early Eocene foraminiferal assemblages have been analysed from an exploratory well (7119/7-1) drilled in the Tromsø Basin (southwestern Barents Sea) and from two onshore sections, Basilikaelva and Kovalskifjella, exposed in the Central Tertiary Basin of Spitsbergen. The assemblages reveal marked differences in taxonomic composition and diversity, reflecting inner neritic to middle bathyal conditions. Within this depth range, four foraminiferal biofacies (FB) are distinguished: FB 1 occurs in the Kolthoffberget Member (of the Firkanten Formation, Late Palaeocene) sampled in the Basilikaelva section. The member consists of interbedded shales, siltstones and sandstones deposited in a transitional delta front - prodelta environment, according to current sedimentological interpretation. The foraminiferal assemblages are entirely agglutinated, show extremely low species diversities and strong dominance of Reticulophragmium arcticum followed by Labrospira aff. turbida. FB 2 is recognised in the Basilika Formation (Late Palaeocene) exposed in the Kovalskifjella section. The formation consists of silty claystones deposited in a prodelta shelf setting. The foraminiferal assemblages show an increased species diversity, and consist mainly of agglutinated taxa with a strongly subordinate calcareous component. The two most abundant species are R. arcticum and L. aff. turbida. Species of Verneuilinoides and Trochammina occur in significant numbers while tubular taxa are rare. FB 3 is found in the Lower Eocene clay interval composing the upper part of the Torsk Formation in well 7119/7-1. It contains entirely agglutinated assemblages with comparatively high diversities. The dominant species are Recurvoides aff. turbinatus and Budashevaella multicamerata, while Reticulophragmium amplectens is typical and common in these strata. Tubular forms referred to Rhizammina occur locally in significant quantities. The diversity and composition of the assemblages suggest an outer neritic to upper bathyal environment. FB 4 is developed in Palaeocene claystones comprising the lower part of the Torsk Formation in well 7119/7-1. In this interval the species diversity, as well as the frequency of tubular forms (referred to Rhizammina, Bathysiphon and Hyperammina) attains maximum values. Other common to dominant taxa include Spiroplectammina spectabilis, Haplophragmoides walteri, Ammosphaeroidina pseudopauciloculata, and Recurvoides sp. These wholly agglutinated assemblages are interpreted as reflecting upper to middle bathyal conditions

Prosthetic Rehabilitation Following Lateral Resection of the Mandible with a Long Cantilever Implant-Supported Fixed Prosthesis: A 3-Year Clinical Report

This clinical report describes the prosthetic management of the surgical reconstruction of a patient after mandibular resection. Complete oral rehabilitation was achieved with a maxillary complete denture and a mandibular implant-supported fixed prosthesis with a custom titanium framework and a long unilateral cantilever

Complete Mouth Rehabilitation and Gastroesophageal Reflux Disease: Conventional and Contemporary Treatment Approaches

This report describes the diagnosis and prosthodontic management of 2 patients with a history of chronic gastroesophageal reflux disease and worn dentition. Different treatment approaches were used for oral rehabilitation. Use of conventional and contemporary restorative materials resulted in functional and esthetic prosthodontic rehabilitation with a favorable prognosis. Gastroesophageal reflux disease (GERD) is a “condition which develops when the reflux of stomach contents causes troublesome symptoms and/or complications. Reflux episodes can be intensified by dietary habits, smoking, physical exercise, and obstructive sleep apnea.Complications of GERD are regurgitation, chest pain, esophagitis, Barrett’s esophagus, esophageal adenocarcinoma, cough, asthma, and dental erosion.GERD is associated with dental erosion and sleep bruxism,and dental erosion may be the only symptom of GERD. The purpose of this report was to present the oral diagnosis and management of 2 patients with chronic GERD who presented with tooth wear and required complete mouth rehabilitation. The restoration of dentition was achieved by following different treatment modalities