Review of nanomaterials in dentistry: interactions with the oral microenvironment, clinical applications, hazards, and benefits.

Interest in the use of engineered nanomaterials (ENMs) as either nanomedicines or dental materials/devices in clinical dentistry is growing. This review aims to detail the ultrafine structure, chemical composition, and reactivity of dental tissues in the context of interactions with ENMs, including the saliva, pellicle layer, and oral biofilm; then describes the applications of ENMs in dentistry in context with beneficial clinical outcomes versus potential risks. The flow rate and quality of saliva are likely to influence the behavior of ENMs in the oral cavity, but how the protein corona formed on the ENMs will alter bioavailability, or interact with the structure and proteins of the pellicle layer, as well as microbes in the biofilm, remains unclear.

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method: dissolution behaviour and biological properties after crystallisation.

Hydroxyapatite (HA), fluor-hydroxyapatite (FHA) with varying levels of fluoride ion substitution and fluorapatite (FA) were synthesised by the sol-gel method as possible implant coating or bone-grafting materials. Calcium nitrate and triethyl phosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride were incorporated for the preparation of the FHA and FA sol-gels.

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method: bonding to titanium and scanning electron microscopy.

Objectives: Hydroxyapatite (HA), fluor-hydroxyapatite (FHA) with varying levels of fluoride ion substitution and fluorapatite (FA) production has been characterised and optimised by the sol-gel method and the dissolution and biological properties of these materials were investigated. It was the objective of this study to investigate the potential bond strength and interaction of these materials with titanium.

Methods: HA, FHA and FA were synthesised by a sol-gel method.

Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method. Optimisation, characterisation and rheology.

Objectives: Currently, most titanium implant coatings are made using hydroxyapatite and a plasma spraying technique. There are however limitations associated with plasma spraying processes including poor adherence, high porosity and cost. An alternative method utilising the sol-gel technique offers many potential advantages but is currently lacking research data for this application.

Orthodontics using an occlusal splint: a clinical report.

Careful management of the occlusion is necessary for successful prosthodontic treatment. A reorganized occlusal approach requires a more accurate registration of the desired jaw position, and where it is difficult to achieve this, an occlusal splint is indicated. This clinical report documents a 60-year-old man with a Prosthodontic Diagnostic Index Class IV dentition, who prior to a full-mouth reconstruction, underwent occlusal splint therapy with a Michigan-type splint that incorporated z-springs to allow concurrent orthodontic tooth movement of two anterior teeth to positions that would allow favorable restorations by correcting occlusal and esthetic form.

Taurodontism--a review.

Unlabelled: Taurodontism is the morpho-anatomical change in the shape of a tooth, which involves enlargement of the body of the tooth and shortening of the roots. It has been reported in permanent and deciduous teeth, in premolars and molars and associated with certain syndromes, particularly in those involving an ectodermal defect. It has clinical implications which are relevant to both the general dental practitioner and the orthodontist.

An analysis of the effect of a vent hole on excess cement expressed at the crown-abutment margin for cement-retained implant crowns.

Purpose: The labial margins of anterior implant-retained crowns are often positioned subgingivally for a superior esthetic appearance. One of the consequences of subgingival margins is the increased risk of leaving excess cement behind following cementation. This can lead to potential problems, including peri-implant inflammation, soft tissue swelling, soreness, bleeding or suppuration on probing, and bone loss.

The effect of engaging the screw access channel of an implant abutment with a cement-retained restoration.

Purpose: Factors affecting the retention of fixed prostheses to natural abutments are well understood. In contrast, little is known concerning the factors influencing the retention of fixed prostheses cemented to implant abutments. The purpose of this study was to investigate the effect that extending a casting into the screw access channel of an implant abutment has on the retention when cemented using Temp Bond.

Effect of a laboratory surfactant on compatibility of type IV dental stones with addition-cured silicone impression materials.

This study compared the effect of a surfactant on surface detail reproduction between combinations of addition-cured silicone impression materials and type IV stones. Six hundred impressions were made of a ruled test block using; Examix-NDS, Doric-Es Flo-Light, Panasil Contact Plus, Extrude Wash and President Plus Jet. Half of the impressions were treated with a surfactant (Aurofilm).

Part-time versus full-time retainer wear following fixed appliance therapy: a randomized prospective controlled trial.

Aim: To compare part-time and full-time Essix-type retainer wear regimens following fixed appliance treatment, with respect to dental alignment and occlusal changes.

Methods: In this prospective study, 60 patients were randomly allocated to either full-time or part-time Essix retainer wear following fixed appliance therapy. Study casts were taken before treatment, at debonding, and 6 months following debonding.

Resin-retained bridges as predictable and successful restorations.

Resin-retained bridges have been used clinically since the 1970s and offer a more conservative approach to the restoration of edentulous spaces than conventional bridgework. They are easy to place, cheap to fabricate, and have been shown to be cost-effective. Despite this, they are not frequently used in general dental practice and have an exaggerated reputation for premature failure.

The importance of dentin collagen fibrils on the marginal sealing of adhesive restorations.

This study evaluated the importance of the union between dentin collagen and three different adhesive materials. Sixty Class V restorations were prepared on the buccal and lingual surfaces of 30 recently extracted human premolars, with the cervical margins in dentin and the occlusal margins in enamel. These restorations were distributed to three groups of 20 cavities each based on the employed adhesive system used: Group A: Single Bond; Group B: Prime&Bond NT; Group C: One Coat Bond.

Smile aesthetics.

Unlabelled: The aim of this article is to outline some of the factors practitioners should take into consideration when planning optimal smile aesthetics. The components of the smile that will be discussed include the smile arc, incisor/gingival display, smile width, gingival aesthetics, tooth proportionality/symmetry, contacts/connectors/embrasures and the dental midlines.

Clinical Relevance: A systematic evaluation of the components of the smile when planning treatment will help to improve smile aesthetics and produce greater patient and dentist satisfaction.

The effects of abutment wall height, platform size, and screw access channel filling method on resistance to dislodgement of cement-retained, implant-supported restorations.

Purpose: Factors affecting the retention of fixed prostheses to natural abutments are well understood. In contrast, little is known concerning factors influencing the retention of fixed prostheses cemented to implant abutments. The purpose of this study was to investigate the effect that varying implant abutment wall height, platform size, and screw access channel filling method has on the retention of castings cemented to implant abutments using TempBond.

Influence of surface treatments on the shear bond strength of Panavia 21 to a Type III gold alloy.

Cylinders of Type III gold alloy were sandblasted with either: 50 micron Aluminium Oxide particles (Group 1); CoJet Sand (Group 2); the CoJet System - CoJet Sand followed by application of silane primer (Group 3). Shear testing was undertaken following apposition of Panavia 21 resin. Mean shear bond strengths (+/- standard deviation) were Group 1, 32.

Reproduction ofarticulator settings and movements with an ultrasonic jaw movement recorder.

The KaVo ARCUS digma is an ultrasonic mandibular movement recorder, which provides articulator setting information for Kavo articulators. The first part of this study examined the ability of the device to record condylar control values pre-set on Kavo's own articulators. Using a mechanical pantograph, the second part of the study tested the ability of the device to record, and then allow reproduction on a Kavo articulator, the movements of a Denar D5A articulator.

The effect of disinfection on irreversible hydrocolloid and type III gypsum casts.

Under standardised conditions, 80 impressions were made of a ruled stainless steel die (ISO Specification 1563) using irreversible hydrocolloid (alginate). The alginates were subsequently treated with 3 commercially available disinfectants, Perform-ID, ImpressiVand Dimenol and poured with type III gypsum. The alginates were evaluated for surface detail reproduction and the gypsum for surface detail reproduction and hardness.

Treatment approaches for developmentally absent second premolars.

Unlabelled: This paper sets out to discuss the treatment options available for the management of patients with agenesis of second premolars. These include: retention of the deciduous molar, extraction followed by space closure, extraction and utilization of the space for the correction of malocclusion and extraction followed by restoration of the edentulous space.

Clinical Relevance: Congenital absence of second premolars is a common clinical problem faced by practitioners.

Hydrogen peroxide tooth-whitening (bleaching): review of safety in relation to possible carcinogenesis.

Hydrogen peroxide in the form of carbamide peroxide is widely used in professionally and self-administered products for tooth whitening. Hydrogen peroxide is a highly reactive substance that can damage oral soft and hard tissues when present in high concentrations and with exposures of prolonged duration. This review examines the issue of oral mucosal damage and possible carcinogenicity relating to the use of hydrogen peroxide in the mouth for tooth whitening, with an emphasis on safety with prolonged exposure to low concentrations of peroxide products.

Effect of screw hole filling on retention of implant crowns.

The screw access channels of 15 degrees angled Esthetic Abutments (Brånemark System) were either (a) completely filled with a vinyl polysiloxane impression material (Memosil), (b) partially filled with Memosil or (c) had lower portion filled with Memosil and the remainder with composite resin. The force required to remove a temporarily cemented restoration was measured. The removal force was significantly reduced with the channel completely filled with Memosil compared to those partially filled with Memosil (p<0.

Type IV gypsum compatibility with five addition-reaction silicone impression materials.

Statement Of Problem: The compatibility of current addition-reaction silicone impression materials and Type IV gypsum products is not completely understood.

Purpose: The purpose of this study was to compare surface detail reproduction between various combinations of contemporary addition-reaction silicone impression materials and Type IV gypsum products.

Material And Methods: Under standardized conditions, 300 impressions were made of a ruled stainless steel die (ADA specification 19), using 5 addition-reaction silicones (Examix-NDS, Doric-ES Flo-Light, Panasil Contact Plus, Extrude Wash, and President Plus Jet).

Influence of flowable liner and margin location on microleakage of conventional and packable class II resin composites.

This in vitro study evaluated gingival wall microleakage in packable and microhybrid conventional composite restorations with and without a flowable composite liner. Each group was evaluated with gingival margins situated in both enamel and cementum/dentin. Two hundred and forty Class II cavities were prepared in extracted third molars, half with gingival margins in enamel and half with margins in dentin/cementum.