Fracture strength of various titanium-based, CAD-CAM and PFM implant crowns.

Objective: CAD-CAM has dramatically advanced dental restorative procedures to include implant-supported crowns. The purpose of this study was to compare the fracture resistance following mechanical loading and thermocycling of various screw-retained and cement-retained ceramic and polymethylmethacrylate material combinations using the TiBase abutment compared to PFM implant-supported crowns.

Overview: Twelve implant restorations were fabricated for each of eight groups.

Fabricating a chairside CAD-CAM radiographic and surgical guide for dental implants: A dental technique.

The conventional method of diagnosing and treatment planning an implant-supported restoration involves making a diagnostic alginate impression and fabricating a radiographic and surgical guide. The procedure described uses an intraoral scanner and milling unit to fabricate a chairside computer-aided design and computer-aided manufacturing radiographic and surgical guide for use with a cone beam computed tomography system.

Effect of Molar Preparation Axial Height on Retention of Adhesively-luted CAD-CAM Ceramic Crowns.

Purpose: To evaluate the effect of axial wall height (AWH) on failure resistance of CAD-CAM adhesively-bonded, all-ceramic crowns on molar preparations with a conservative total occlusal convergence (TOC).

Materials And Methods: 60 newly extracted maxillary third molars were divided into 5 groups (n = 12) and prepared for all-ceramic crowns with occlusal cervical AWH of 0, 1, 2, 3, and 4 mm, all containing a conservative 10-degree TOC. Scanned preparations were fitted with lithium-disilicate glass-ceramic crowns using a self-adhesive resin-composite luting agent after intaglio surface preparation with hydrofluoric acid and silane.

Fracture resistance of all-ceramic crowns based on different preparation designs for restoring endodontically treated molars.

Objectives: To evaluate endodontically treated molar fracture resistance restored with CAD/CAM lithium disilicate (LDS) crowns with different amalgam core preparation design.

Materials And Methods: Eighty-four recently extracted mandibular third molars were divided into seven groups (n = 12) and embedded in autopolymerizing resin. Coronal tooth structure was removed, pulp chamber exposed, and pulpal remnants removed.

'If experts differ, what are we to do in the matter?' The Medico-legal Investigation of Gunshot Wounds in a 1927 Scottish Murder Trial.

This article uses a notorious criminal trial, that of John Donald Merrett for the murder of his mother, as a case study to explore forensic medicine's treatment of gunshot wounding in pre-war Scotland. This topic, which has hitherto received little attention from historians, provides insight into two issues facing the discipline at this time. First, the competing attempts by prosecution and defence expert witnesses to recreate the wound in a laboratory setting, in order to determine the distance from which the shot had been fired, exposed the uncertainties surrounding the application of a well-known laboratory technique for which no fully agreed-upon protocol existed.

Effect of Premolar Axial Wall Height on Computer-Aided Design/Computer-Assisted Manufacture Crown Retention.

Purpose: To evaluate the effect of premolar axial wall height on the retention of adhesive, full-coverage, computer-aided design/computer-assisted manufacture (CAD/CAM) restorations.

Materials And Methods: A total of 48 premolar teeth randomized into four groups (n = 12 per group) received all-ceramic CAD/CAM restorations with axial wall heights (AWH) of 3, 2, 1, and 0 mm and 16-degree total occlusal convergence (TOC). Specimens were restored with lithium disilicate material and cemented with self-adhesive resin cement.

Bicuspid Axial Wall Height Effect on CAD/CAM Crown Fracture Mode on Preparations Containing Advanced Total Occlusal Convergence.

Purpose: To evaluate bicuspid axial wall height effect on the fracture mode of adhesively luted, all-ceramic CAD/CAM crowns with a 20° total occlusal convergence (TOC).

Materials And Methods: Recently extracted premolars were randomly divided into 4 groups (n = 12) with all-ceramic crown preparations accomplished using a high-speed handpiece inserted into a milling device. Specimens were prepared containing occlusogingival axial wall heights of 3, 2, and 1 mm as well as a group containing a flat preparation surface with no axial wall height.

Failure load effect of molar axial wall height with CAD/CAM ceramic crowns with moderate occlusal convergence.

Objectives: To evaluate the significance of axial wall height (AWH) in molar fracture resistance involving CAD/CAM adhesively bonded, all-ceramic full coverage restorations on preparations with moderate total occlusal convergence (TOC) (16°).

Materials And Methods: 60 newly extracted maxillary third molars were divided into 5 groups (n = 12). Specimens were prepared for full-coverage, all ceramic restorations with occlusal cervical AWHs of 4, 3, 2, 1 as well as a flat preparation (0 mm AWH) with all preparations with AWH containing a moderate 16° TOC.

'From Defensive Paranoia to …Openness to Outside Scrutiny': Prison Medical Officers in England and Wales, 1979-86.

This article examines how a branch of medicine based within the criminal justice system responded to a society which by the 1970s and 1980s was increasingly critical of the prison system and medical authority. The Prison Medical Service, responsible for the health care of prisoners in England and Wales, was criticised by prison campaigners and doctors alike for being unethical, isolated, secretive, and beholden to the interests of the Home Office rather than those of their patients. While prison doctors responded defensively to criticisms in the 1970s and 1980s, comparing their own standards of practice favourably with those found in the NHS, and arguing that doctors from outside would struggle to cope in the prison environment, by 1985 their attitudes had changed.

Preparation Ferrule Design Effect on Endocrown Failure Resistance.

Purpose: To evaluate the effect of preparation ferrule inclusion with fracture resistance of mandibular molar endocrowns.

Materials And Methods: Recently extracted mandibular third molars were randomly divided into 3 groups (n = 12) with the coronal tooth structure removed perpendicular to the root long axis approximately 2 mm above the cemento-enamel junction with a slow-speed diamond saw. The pulp chamber was exposed using a diamond bur in a high-speed handpiece with pulpal remnants removed and canals instrumented using endodontic hand instruments.

Selected physical properties of new resin-modified glass ionomer luting cements.

Statement Of Problem: Two resin-modified glass ionomer (RMGI)-based luting agents have been recently marketed without independent reports of their physical properties.

Purpose: The purpose of this in vitro study was to evaluate selected physical properties of 2 newly marketed RMGI luting agents and compare the findings with traditional materials.

Material And Methods: Specimens (N=12) of Nexus RMGI, UltraCem, GC Fuji Cem 2, and RelyX Luting Plus were fabricated using standardized molds for flexural strength and fracture toughness according to manufacturer recommendations and stored in physiologic phosphate-buffered saline solution at 37°C until testing.

The comparative efficacy of 0.12% chlorhexidine and amoxicillin to reduce the incidence and magnitude of bacteremia during third molar extractions: a prospective, blind, randomized clinical trial.

Objective: The purpose of this study was to directly compare the incidence and magnitude of bacteremia of a 0.12% chlorhexidine pre-procedure rinse to the AHA and the ADA/AAOS recommended 2 g amoxicillin antibiotic prophylaxis during third molar extractions.

Study Design: This study was a randomized, blind, placebo-controlled prospective clinical trial involving subjects assigned to a placebo, rinse, or antibiotic group.

Application of the functionally generated path technique to restore mandibular molars in bilateral group function occlusion.

The functionally generated path (FGP) is a static representation of the opposing cusps' dynamic eccentric movements from a centric position to achieve optimal articulation and occlusal harmony. When understood and appreciated, use of the FGP technique is a straightforward and practical method to achieve harmonious occlusal anatomy of restorations with the anterior determinant/anterior guidance, the posterior determinant/condylar guidance, existing occlusal and cuspal anatomy, and the neuromuscular system. Although the FGP technique is normally used in the fabrication of maxillary posterior indirect restorations, it is described and applied here in the fabrication of mandibular posterior restorations that maintained the patient's bilateral group function occlusion while eliminating the nonworking side and protrusive interferences.