Education. Prepare to pair.
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Clinical Clerkship↗
Biomedical subjects
A J Qualtrough
Publications and source records attributed to A J Qualtrough.
Aesthetic inlays: composite or ceramic?
As the aesthetic aspect of dental care becomes increasingly important to patients, the dental practitioner should be aware of the applications and limitations of the various tooth-coloured restorative systems available for the restoration of posterior teeth. Among currently available systems are direct placement resin composites, which may find application in small to medium preparations, and composite or ceramic inlays, which may have wider applications. Similar principles of inlay cavity preparation and restoration placement may be applied to both composite or ceramic systems, with both having the advantage over directly placed composite materials of improved control over anatomic form. Ceramic inlays may provide a high level of wear resistance, but are less simple to construct or repair than composite inlays. While initial clinical trials of composite and ceramic inlays show promise, long-term trials are now required to more fully assess the longevity of these restorations in clinical use.
Bicuspid↗
A look at dental esthetics.
The surge of interest in the use of tooth-colored restorative materials and systems in recent years has been attributed partly to rapid developments in dental materials science and also to patient demand and operator interest. When overall dental appearance is considered, several factors are of significance, including tooth color, shape, and position; restoration quality; and the general arrangement of the dentition, especially of the anterior teeth. Each factor may be considered individually, but all components together act in concert to produce the final esthetic effect. However, although the clinician must be mindful of the patient's desires for a favorable cosmetic result, materials and techniques must be carefully selected, and restorations should be sufficient to withstand the forces of occlusion and mastication and provide long-term function.
Color↗
A comparison of two in vitro methods for assessing the fitting accuracy of composite inlays.
Composite inlays were fabricated in standardised cavities cut into aluminum and perspex blocks using a computer controlled milling process. Four materials were used to construct the inlays. These were fabricated using an indirect technique following the manufacturers' recommendations, where applicable. In addition, for one of the composites, the fabrication procedures were modified. The fitting accuracy of the restorations was assessed by taking elastomeric impression wash replicas of the luting space and by examination of sectioned restored units using image analysis. The former method indicated significantly reduced fitting accuracy when either use of die spacer or secondary curing was omitted from restoration construction resulting in incomplete seating. The sectioning technique indicated that more factors appeared to significantly reduce fitting accuracy including bulk packing, alteration in curing time, omission to die spacer and the final polishing procedure. This method also provided more specific information concerning sites of premature contact. One material gave rise to significantly greater film thicknesses using both methods of assessment. No direct correlation was found between the two techniques of fit evaluation but both methods taken together provided complementary information.
Acrylic Resins↗
Dental education in Japan.
Expanded roles for chairside assistants, infrequent use of amalgam, and dental technician courses over-subscribed by three to one. Perhaps this isn't the classic image of the advanced society that Japan has become over the last 40 years, yet the dentists working and researching in this economic spearhead were full of enthusiasm for their profession. On our journey to the far east we would be greeted with many surprises, especially in dental practice and hygienist education.
Dental Amalgam↗
Matrices: their development and in clinical practice.
Recent developments in amalgam alloys composite resin materials have highlighted the importance of meticulous restoration placement by the dentist. This paper discusses the selection and use of the matrix which is significant in both the quality and longevity of the final restoration.
Dental Restoration, Permanent↗
Fitting accuracy of indirect restorations: a review of methods of assessment.
The current interest in indirectly manufactured, tooth-coloured restorations has highlighted a need to identify factors pertinent to the success of both these and other indirect restorations. Although restoration longevity is limited by the degree of adaptation to the prepared tooth, there exists no standard method for either the assessment of marginal adaptation or the overall accuracy of fit. This review examines methods of assessment of both of these important parameters, and considers the problems associated with existing in vivo and in vitro techniques.
Crowns↗
Tooth coloured inlays: state of the art.
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Bicuspid↗
The history, development and use of interproximal wedges in clinical practice.
Wedges, when correctly selected and applied, can make an important contribution to the initial quality and the longevity of some restorations, and can greatly facilittae a number of clinical procedures. The authors outline the important role of interproximal wedges in restorative dentistry, and, in an historical perspective, describe how the principles elucidated when wedges were first employed in restorative dentistry more than 150 years ago are still applicable today.
Dental Restoration, Permanent↗
Dental ceramics--an update.
The application of certain industrial ceramics and processing techniques has facilitated the introduction of a wide range of new dental restorative products including castable glass-ceramics, shrink-free materials and an ion-strengthening paste. However, these recent advances must be evaluated against the well-established materials and techniques developed more than 20 years ago. This article outlines interesting developments in the evolution of dental ceramics over the past 30 years and considers the current state of the art.
Ceramics↗
An investigation into antibiotic prescribing at a dental teaching hospital.
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Adolescent↗
Dentine-bonded ceramic crowns: two case reports.
The dentine-bonded ceramic crown is a full coverage restoration luted to the underlying tooth tissue via a dentine bond and resin composite luting system. The main advantage of using this technique is that removal of tooth tissue can be kept to a minimum. Additionally, the final aesthetic results may be excellent. In this paper, the provision of dentine-bonded crowns on the upper anterior teeth for two patients is described.
Adolescent↗
Lithium ion strengthening of dental porcelain.
The effects of experimental lithium-containing ion exchange pastes on dental porcelain were compared with a commercial ion strengthening paste. Maximum biaxial flexure strength using the experimental pastes was obtained by firing lithium paste containing 200 g per L lithium sulphate dihydrate for 45 minutes at 750 degrees C onto the surface of the porcelain. However, the commercial paste produced the greatest strengthening overall.
Aluminum Oxide↗
Influence of different transitional restorations on the fracture resistance of premolar teeth.
Controversy exists over the most favorable material and type of restoration to be used to transitionally restore teeth destined to be crowned. This in vitro study uses fracture resistance testing to compare eight different transitional restorations in maxillary premolars. Ninety sound maxillary premolars were randomly selected and allocated to nine groups, each comprising 10 teeth. One group remained unrestored and was used as the control. Teeth in the remaining groups were prepared to a standard cavity form using: a copy milling process removing the palatal cusp. Restorations were placed using amalgam with dentin pins and cavity varnish; amalgam with an amalgam bonding agent; resin composite with dentin pins and a dentin bonding agent; resin composite with a dentin bonding agent only; resin-modified glass ionomer with dentin pins; resin-modified glass ionomer cement alone and cermet with dentin pins and cermet alone. Each restored tooth was then subjected to axial loading via a bar contacting the buccal and restored palatal cusps until failure of the restored tooth occurred. The mean load-to-fracture values were statistically compared and the modes of failure recorded. It was found that the choice of restorative material and type of restoration had little effect on the fracture resistance of the restored tooth with the exception of those teeth restored with reinforced glass ionomer cement alone, which exhibited a significantly lower resistance to fracture than the other restored teeth. However, the choice of restorative material/technique did influence the mode of failure. Failure in teeth restored with resin-modified glass ionomer cement alone produced the least damage to the remaining tooth tissue when failure occurred. Consequently, this material may offer the most favorable range of properties for the transitional restoration of extensively broken-down maxillary premolar teeth destined to be crowned. Furthermore, the findings of this study fail to support the use of dentin pins in the placement of bonded build-up restorations.
Analysis of Variance↗
An investigation of an ion strengthening paste for dental porcelains.
The effect of a commercial ion exchange paste on the tensile strength of high- and low-expansion dental porcelains was investigated. Strength measurements were correlated with changes in surface chemistry. The paste was found to be more effective for aluminous porcelains than for an inlay ceramic, although only when applied to the surface placed in tension. Surface finish also influenced the effectiveness of the paste. The depth of ion exchange was assessed by energy dispersive x-ray analysis and was found to extend to at least 100 microns, although the most marked change occurred within a 10-microns layer below the surface.
Aluminum Oxide↗
An in vitro evaluation of the marginal integrity of a porcelain inlay system.
There is currently no consensus of opinion regarding form of the finish line for porcelain inlays. This study compared beveled and nonbeveled finishing lines. Twenty-four Class II MOD cavities of a standardised design were prepared in extracted premolar teeth. Twelve were finished using a half enamel occlusal bevel and 12 were not beveled. Porcelain inlays were fabricated and luted with a dual-polymerizing resin material. The completed restorations were stored in water, thermocycled, and analysed using a scanning electron microscope. The quality of the enamel/composite resin interface was found to be considerably better than that of the inlay/composite resin interface. The adaptation of composite resin to enamel was of equal quality for both beveled and nonbeveled preparations.
Composite Resins↗
Porcelain inlay: a historical view.
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Dental Porcelain↗