Don Schwass

• BSc BDS(with distinction) DClinDent FPFA
• Professor (Associate) at University of Otago

Objective To investigate the perceived educational and health risks associated with the COVID‐19 pandemic amongst dental students and educators. Methods A 17‐item electronic survey was sent to 496 undergraduate dental students and 53 clinical faculty members who attended clinical sessions during the outbreak period. The survey explored various asp...

Purpose/objectives: Due to the nature of the profession, dental healthcare workers are exposed to infectious diseases such as coronavirus disease 2019 (COVID-19), and the severity of the pandemic presents challenges to dental education institutions worldwide. This study investigated dental students and clinical staff perceptions of health risks an...

Objectives: To evaluate the effect of Beam Hardening Correction tool (BHC) on Micro-CT images used in the diagnosis of incipient caries lesions. Methods: Six posterior teeth, with 6 sound proximal surfaces and 6 natural white spot lesions, were scanned using a SkyScan1174 device. Each tooth was imaged 16 times in various acquisition parameters,...

The objectives of the study were to quantify the dentine mineral concentration (DMC) in teeth restored conventionally, according to the atraumatic restorative treatment (ART) and ultraconservative (UCT) protocols (open cavities and small ART restorations), and the DMC underneath the open cavities of teeth managed by UCT versus nontreated, open cavi...

A novel silver nanoparticle (AgNP) formulation was developed as a targeted application for the disinfection of carious dentine. Silver nitrate (AgNO3) was chemically reduced using sodium borohydrate (NaBH4) in the presence of sodium dodecyl sulfate (SDS) to form micelle aggregate structures containing monodisperse 6.7- to 9.2-nm stabilized AgNPs. A...

Background Application of astringent hemostatic agents is the most widely used technique for gingival retraction, and a variety of products are offered commercially. However, these products may have additional unintended yet clinically beneficial properties. The authors assessed the antimicrobial activities of marketed retraction products against p...

This study aimed to assess whether resin infiltration of primary molar proximal lesions is more effective than noninvasive measures in radiographically controlling carious lesion progression into the dentin. A split-mouth randomized controlled trial included 90 children, each with 2 proximal lesions confined to the inner half of the enamel or ≤0.5...

Background Intraoral adjustment and polishing of dental ceramics often affect their surface characteristics, promoting increased roughness and consequent biofilm growth. This study correlated surface roughness to biofilm development with four commercially available ceramic materials. Methods Four ceramic materials (Vita Enamic®, Lava™ Ultimate, Vi...

The aim of this pilot study was to evaluate the feasibility of a new tooth preparation assessment software, Preppr, as an educational tool for dental students in achieving optimal parameters for a crown preparation. In February 2015, 30 dental students in their fourth year in a five-year undergraduate dental curriculum in New Zealand were randomly...

Objectives Success rates of dental crowns are influenced by the clinician’s ability to provide a retentive yet conservative preparation. The recommended total occlusal convergence (TOC) angles are between 10o – 20o and a minimal margin width of 1mm for all-ceramic crowns. Conventionally, dental students are provided written/pictorial instructions...

Aim: To assess the effectiveness of CBCT for quantifying tissue development around grafted sinus sites, using an animal model. Material and Methods: Sinus grafting in eight sheep with bovine xenograft was evaluated after a 16 week healing period. Specimens from each animal were analysed histomorphometrically using three techniques: 3-D computerise...

A strategy to prevent and treat tooth decay, which utilises electrophoretic movement of charged, antibacterial silver nanocomposite structures to infiltrate human dentine to target bacteria contained within the dentine tubules, has been developed and evaluated. Scanning electron microscopy and energy-dispersive X-ray spectroscopy have confirmed hig...

In this work we identify an effective cmc boundary for a model ionic surfactant/metal salt system (sodium dodecylsulfate/silver nitrate; SDS/AgNO3), and demonstrate the importance of this boundary with respect to surfactant- and/or micelle-templated synthesis of metal nanoparticles. By preparing SDS-stabilized silver nanocomposite materials using a...

With the Internet facilitating access to vast amounts of free information, dental practitioners face providing treatment for an increasingly informed public. However, the available content is not filtered, and it can be difficult for patients to discriminate between research-informed evidence and "glamorised" material of dubious origin. Patients re...

Teeth are important elements in studies of modern and fossil Cetacea (whales, dolphins), providing information on feeding habits, estimations of age and phylogenetic relationships. The growth layer groups (GLGs) recorded in dentine have demonstrated application for aging studies, but also have the potential to elucidate life history phenomena such...

We present a new twist on a conventional nanoparticle preparation method, which allows the one-pot synthesis of two fractions of size-controlled, spherical, monodisperse silver nanoparticles (Ag NPs), one fraction of which can be suspended in organic solvent, and the other can be suspended in aqueous or other polar solvents, with no significant cha...

Teeth are important elements in studies of modern and fossil Cetacea (whales, dolphins), providing information on feeding habits, estimations of age and phylogenetic relationships. The growth layer groups (GLGs) recorded in dentine have demonstrated application for aging studies, but also have the potential to elucidate life history phenomena such...

Objectives: It is of imperative clinical significance to define a safe threshold for planned immediate implant restoration. The aim of this report was to evaluate the prognostic accuracy of resonance frequency analysis (RFA) measurements recorded at two different times (implant placement and 8-week post-implant placement) and to determine the opti...

Objective: To use finite element analysis to investigate the influence of insertion torque on the stress distribution around an immediately placed oral implant. Method and materials: Finite element software was used to model a mandibular molar extraction socket. The properties of surrounding cancellous bone and thickness of cortical bone were mo...

BACKGROUND: In the replacement of missing teeth, a paradigm shift is currently observed with immediate implant placement and/or restoration, particularly in the aesthetic zone. In molar sites, however, anatomical, occlusal and biomechanical considerations remain deterrent factors influencing the outcome of this treatment paradigm. The aim of this r...

Desktop microcomputed tomography (micro-CT) offers a non-invasive 3-dimensional analysis of structures and their physical properties. To date, the use of micro-CT has mostly involved qualitative observations, with the extent of quantitative analysis relying on automated internal calibration by the micro-CT control software. However, the value of su...

The authors reviewed and compared gingival retraction techniques used for implants and teeth. The authors searched the literature using article databases Ovid MEDLINE up to May 2008, PubMED and Google Scholar (advanced search) and the following search terms: gingival retraction, implant abutment, impressions, cement-retained implant restoration, im...

The potential for cross infection through dental amalgam carriers was investigated in 37 Dunedin dental practices and in the University of Otago School of Dentistry. Eighteen practitioners had autoclavable carriers, but only 2 autoclaved them at least daily. The School of Dentistry disinfected plastic carriers and autoclaved metal carriers. Microbi...

Introduction: Micro-Computed Tomography (MicroCT) allows non-invasive investigation of 3-dimensional structures and analysis of mineral density profiles. The Er:YAG laser(KaVo Key III laser), operating at 294nm, is effective at removal of dental hard tissues. Autofluorescence, characteristic of carious dental hard tissues but not of sound tissues,...