Primary dental journal最新文献

Aim: The dental handpiece noise in a dental surgery is concerning to both patients and staff as a major cause of dental phobia in patients and potential hearing loss in clinical staff. High-frequency noise generated by dental handpieces is considered to be the worst of the many noises in a dental clinic. Methods to reduce this noise have been proposed and either passive or active noise reduction headphones are often suggested. However, in a dental surgery environment, the need for good verbal communication with the patient needs to be maintained. As a result, this paper aims to evaluate one proprietary anti-noise device considered suitable for this specific purpose.

Methods: Lab-based experiments were set up and carried out to evaluate QuietOn, using GRAS 43AG-1 Ear and Cheek Simulator to mimic a section of the human head and ear to represent the acoustic characteristics of an actual ear. Two types of dental drill noise recordings, one for electric motor-driven and another one for air turbine-driven, were played back through high-definition speakers. Sound data captured by the simulator are then visualised and plotted using MATLAB for analysis.

Main findings: QuietOn is effective at low frequencies (< 1kHz). However, when dealing with high-frequency noise such as dental handpieces it is ineffective yet subdues verbal communication.

Conclusions: Further development of passive or active noise cancellation earplugs is still needed to target dental handpiece noise while maintaining verbal communication.

Fibrous ridges on the edentulous maxillary arch are commonly found in combination syndrome or due to ill-fitting dentures. Often, these cases are managed conservatively using modified impression techniques to achieve better support and peripheral seal without displacing the movable tissue. Many impression techniques were proposed and justified with their respective ideologies, but some may complicate both the clinical and laboratory procedures. In this report, two simplified techniques are demonstrated to make an impression of the maxillary arch with fibrous ridges. Laboratory steps in custom tray fabrication are also emphasised for a successful and predictable impression.

Introduction: The preparation of parallel axial wall guide planes in abutment teeth is essential for providing a correct path of insertion and removal axis for removable partial dentures (RPDs). With the introduction of digital resources, new alternatives to the conventional method can be used to manufacture guide preparation for guide planes.

Aims: To describe the use of computer-aided design/computer-aided manufacturing (CAD/CAM) technology for the manufacture of guide planes to guide the reduction of the axial walls of abutment teeth according to the insertion and removal axis of the RPD.

Methods: This technique used the "bite splint" module of the Dental Wings software for the virtual planning of guide planes, to promote the construction of axial walls parallel to the abutment teeth. This was performed from the virtual design on a standard tessellation language (STL) file obtained by intraoral scanning, which determined the best trajectory for insertion and removal of the metallic structure.

Conclusion: Digital technology allows the design and production of guide planes for the preparation of abutment teeth, simplifying the conventionally used technique, with precision and speed.

Purpose: The purpose of this systematic review was to compare the clinical performance of lithium disilicate (LDS) and zirconia (Z) single crowns manufactured by computer-aided design/computer-aided manufacturing (CAD/CAM) systems using intraoral optical scanners (IOS).

Materials and methods: An electronic search for articles published between January 2012 and January 2022 in the English language was performed with the Medline/Pubmed database under the guidelines of Preferred Reporting Items for Systemic Reviews and Meta-analysis (PRISMA). The specific search terms used were "zirconia", "lithium disilicate", "CAD/CAM", "intraoral optical scanner", and "survival".

Results: The initial electronic search resulted in 278 articles. Most of the resulting articles were excluded, six clinical studies addressing the clinical outcomes of Z and LDS crowns fitted the inclusion criteria and were selected for review. Of these six studies, three were randomised controlled trials, two were retrospective studies, and one was a prospective study. To quantify the clinical performance of the crowns several parameters were recorded, including fractures, endodontic complications, periodontal complications, technical complications, aesthetic complications, and biological complications. It was noted that the most common technical complication of Z and LDS crowns was chipping at a rate of 1.4% and 5% respectively. Regarding Z crowns, aesthetic concerns were the most frequently observed complication.

Conclusion: The outcomes of this systematic review indicate that Z and LDS crowns display a similar incidence of periodontal and endodontic complications when compared to metal-ceramic crowns, suggesting that these all-ceramic materials are viable alternatives. The incidence of chipping was higher in LDS crowns compared to other materials, while Z crowns were inferior in terms of aesthetics.

This article is based upon a webinar presented by the author in July 2022 as part of the ongoing collaboration between CGDent and ProDental CPD, and the handouts provided for those webinar participants. It also reflects the author's seminar given at the Dentistry Show in London in October 2022. Some of the background information also appeared in lectures on this topic given by the author to the UK Committee of Postgraduate Dental Deans and Directors (COPDEND) and East Midlands Dental School in 2015-2017. It aims to bust some myths about the duty of candour as it applies to dentistry and explains its implications for practice owners, dentists and other team members, the conversations we need to be having and the records we need to keep in order to satisfy the legal, ethical and perhaps contractual aspects of this duty, as well as the human aspects. It should be noted that the situation regarding the legal duty of candour differs across the four nations of the UK; this article explains the dynamic nature of those differences, but in terms of detail it focuses upon the situation as it exists in England where the duty has existed for much longer and affecting more members of the dental profession.