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Biomedical subjects

G Soh

Publications and source records attributed to G Soh.

At least 37 records · Page 2Linked to original sources
PubMed1991

Dental care of institutionalized elderly in Singapore.

Previous studies have identified considerable barriers to dental care and unmet dental needs among institutionalized elderly. This study examined physical and financial arrangements for dental care of institutionalized elderly in Singapore. Chief administrators of the 68 homes for the elderly in Singapore were interviewed. Results showed that 48 homes (70.7%) assumed responsibility for arranging dental care and providing access to treatment facilities for its ambulant residents while only 33 homes (48.5%) had similar arrangements for semi- and non-ambulant residents. Four of the homes (5.9%) reported having in-house dental facilities while the rest arranged for its residents to be treated either in public dental facilities (44.2%) or in private dental offices (20.6%). Type of sponsorship of the homes and ambulatory status were closely associated with the type of arrangement for dental care. Over 64.6% of homes (44) required residents to be fully responsible for the costs of their dental care. The availability of subsidies for residents' dental costs was found to be associated with the type of sponsorship and type of arrangement for care. Lack of physical access and financial constraints were found to be potential problems in the utilization of dental services in this population group.

Aged↗
PubMed1991

Thermal effect on the dissolution of mercury from two dental amalgams.

Various factors affect dissolution of mercury from dental amalgams. In this study we examined the effect of temperature on the release of mercury from two dental amalgams, namely an admixed high-copper amalgam (Contour) and a new tin- and copper-free amalgam (Composil). Ten cylindrically-shaped specimens of each type of amalgam were used in this investigation, and were divided into two equal groups. The five specimens in each group were each incubated in 10 ml purified water at either 37 degrees C or 60 degrees C, with a change of water every 24 h over an 8-day period. The quantity of mercury released from each amalgam specimen during each incubation period was expressed as micrograms cm-2 24 h-1. The amount of mercury released was estimated by cold-vapour atomic spectrometry. The results demonstrate that specimens incubated at 60 degrees C released significantly larger amounts of mercury than specimens incubated at 37 degrees C for both types of amalgam. The release of mercury by Composil was significantly greater than that by Contour (P less than or equal to 0.0001) for both temperatures studied. Raising the incubation temperature caused a disproportionate increase in mercury release from Composil compared to Contour.

Copper↗
PubMed1991

Defects in automixed addition silicone elastomers prepared by putty-wash impression technique.

Voids presenting in impressions of five automixed addition silicone elastomers were investigated. Impressions were prepared with the putty-light body impression technique on stainless-steel cylinders with acrylic spacers. The number of voids was counted at a predetermined site on three separate days using a stereomicroscope at x7 magnification. Impression specimens of a hand-mixed addition silicone, and from hand-mixing of the automixed materials, were made for comparison. Express gave a significantly higher number of voids than other automixed materials, with President Jet having the lowest void count. Automixed materials generally produced impressions with significantly fewer voids than the hand-mixed material. Automixing was effective in reducing void defects in elastomeric impressions.

Dental Impression Materials↗
PubMed1991

Dental health of disabled children in Singapore.

The oral health status of the disabled has generally been poorer than the general population as the treatment and care afforded to them has been minimal. This paper examines the relationship of the various types of disabilities to dental health status. The dental status of a random sample of 322 disabled children aged between 6 and 18 years was assessed. The children had various disabilities: intellectual, hearing, visual, and musculo-skeletal. Most differences in the prevalence and severity of the dental conditions assessed among the children in the various disability groups were not significant. However, in comparison with normal schoolchildren aged 6 to 18, the disabled children had higher levels of disease and received less dental attention.

Adolescent↗
PubMed1991

Effectiveness of intraoral delivery tips in reducing voids in elastomeric impressions.

Voids in impressions made by five automixed addition silicone elastomers with and without intraoral delivery tips were investigated. The number of voids were counted at a predetermined site on 3 days. Hand-mixed impressions of the automixed materials were made for comparison. There was no statistically significant difference in the mean number of voids produced in each automixed silicone dispensed with the use of intraoral delivery tips and the number of voids produced without the use of the tips. However, there were significant differences in the number of voids among different materials. The rank order of the automixed silicone elastomers was fairly consistent, with Express producing the highest and Reprosil the lowest number of voids. Automixed silicone materials should only be prepared by automixing for optimal results.

Air↗
PubMed1991

Effect of interchanging automatic mixing tips on void formation for an automixed addition silicone impression.

This study examined the effect of interchanging mixing tips on void formation for impressions of an automixed addition silicone material. The impressions were made of a series of stainless-steel cylinders by two dentists. The voids were counted at a predetermined site with a binocular microscope. The results showed that there were no significant variations in the number of voids in impressions of the automixed addition silicone using the three different mixing tips. However, one dentist made impressions that had substantially less voids for all three mixing tips.

Air↗
PubMed1991

Patient satisfaction with physician care.

Patient satisfaction is known to be related to many desired outcomes in medical care. This study employees multidimensional scaling techniques to identify factors affecting satisfaction with physician care in 1,210 patients. Stepwise regression analysis of factors that met predetermined criteria showed that accessibility explained the greatest amount of variance in patient satisfaction. The patient's perceived efficacy of physician care and greater continuity of care also have significant correlations with satisfaction. Perceived susceptibility to illness, utilization of physician services, and levels of education have lesser but significant effects on patient satisfaction. Despite methodological constraints, economic and psychological benefits make evaluation of patient satisfaction an important exercise.

Adolescent↗
PubMed1991

Understanding prevention of dental caries and gum disease in an Asian community.

Prevention is recognized as a cost-effective method for the control of oral diseases. Knowledge of prevention can influence preventive dental behaviour. This study surveyed knowledge on the prevention of dental caries and gum diseases among a selected group of adults. Respondants were asked to indicate the importance of numerous preventive measures for prevention of both categories of oral diseases. Results showed that while respondents appropriately identified the importance of regular brushing for prevention, the role of flossing is underestimated. Similarly, there was a lack of appreciation for the value of various fluoride treatment modalities in preventing dental caries. A lack of understanding of dental sealants was also evident. It is concluded that public knowledge on prevention of dental caries and gum disease deviates greatly from current scientific information.

Adult↗
PubMed1991

Significance of hydrogen ion concentration on the dissolution of mercury from dental amalgam.

The potential risks of mercury dissolution from dental amalgam have long been recognized. This study examined the effect of hydrogen ion concentration on the release of mercury from two dental amalgams: an admixed high-copper amalgam and a new tin- and copper-free amalgam. Specimens of each type of amalgam were incubated citric acid buffer of pH 2.5 or pH 7.0. Results showed that, for both types of amalgam, specimens incubated at pH 2.5 released statistically significantly greater (P less than .0001) quantities of mercury than did specimens incubated at pH 7.0. Release of mercury from the tin- and copper-free amalgam was also statistically significantly greater (P less than .0001) than that of the higher-copper amalgam at both pH levels.

Citrates↗
PubMed1990

Relationship between contact angles of die stone on elastomeric impression materials and voids in stone casts.

Poor wettability of elastomeric impression materials results in surface defects on stone casts. This study examined the relationship between contact angles of die stone and voids in casts produced from five medium-viscosity impression materials. Contact angles of a die stone material formed against impression specimens made from polyether, addition and condensation silicones were measured by reflex microscope. The contact angle values achieved on the hydrophilic addition silicones were significantly higher than the polyether but lower than other silicone materials. Contact angle values correlated with the number of voids found at margins and line angles of stone casts but not with those on smooth surfaces.

Dental Impression Materials↗
PubMed1990

Effect of thermal stress on dentin adhesives used individually and in combination.

Polymerization shrinkage remains an inherent problem in composite restorations. Dentin adhesives generally improve bonding to dentin but do not consistently provide leak-free restorations. This study evaluated a dentin adhesive that bonds to dentinal calcium and another that bonds to dentinal collagen when used separately and in combination. The measurement of contraction gaps at the restoration-dentin interface was used as the means of testing the effectiveness of dentin adhesion. The effect of thermal stress on the dentin-polymer bond was also investigated. Results showed that the bisphenyl A glycidyl methacrylate (BISGMA)-based dentin adhesive was more effective when compared with the hydroxyethyl methacrylate (HEMA)-based adhesive. When used in combination, the mean contraction gaps of cavities were not found to be significantly better than those treated with only the BISGMA-based adhesive. Thermal stress reduced the effectiveness of dentin adhesives whether applied individually or in combination.

Composite Resins↗
PubMed1990

Relationship between critical convergence angle and surface defects in stone casts.

Surface defects on stone casts threaten the accuracy of cast restorations. The aim of this study was to examine the relationship between critical convergence angle and voids in stone casts. Three addition silicone materials, one condensation silicone material, and one polyether impression material were used. The highest convergence angle at which voids presented at the tip of the specimens was recorded, and the number of voids found at margins and line angles of the tooth preparations were counted. Results showed a positive and significant correlation between the critical convergence angle and the number of voids at margins and line angles of stone casts. Casts poured from polyether impressions registered significantly lower critical convergence angle values and presented with fewer voids than did those fabricated from silicone materials.

Calcium Sulfate↗
PubMed1990

Institutional advertising: boon or bane?

Dental advertising has long been considered an anathema by the dental profession. However, in recent years, legalisation of dental advertising in the United States and later, Britain, introduced a new dimension into dental advertising. Professional organisations which decided on institutional advertising had reported impressive returns. The benefits and shortcomings of institutional advertising are discussed.

Advertising↗
PubMed1990

Applications of computer technology in dentistry.

Technological advances in industrial manufacturing have contributed to improvement in productivity and quality of dental care. However, computer technology has also been exploited but not to the same extent as other forms of technology. This paper examines computer applications that have been utilised by various groups of dental professionals in the provision of dental care and in dental education. The benefits derived from existing applications and future possibilities are seen in the following fields. In practice management, besides the usual collecting, sorting and searching of data, productivity and efficiency are greatly increased through computer appointments, recall and practice analysis programmes. In patient education, the use of computer graphics has enabled simulation of cosmetic changes to be presented to the patient with before and after possibilities. Dental education and communications have moved forward with the introduction of Computer Assisted Instruction programmes, and bibliographic databases including electronic transmission of Continuing Dental Education which are now easily available. In the field of Diagnostics and Treatment planning, the advent of CAD-CAM has made possible the use of cutting devices which mills a 3-dimensional model of the designed restoration from solid blocks of gold. Computer applications has also been used in forensic dentistry where identification systems describe tooth conditions and other oral characteristics besides automated screening and matching of antemortem databases.

Computer-Assisted Instruction↗
PubMed1989

Comparison of release of mercury from three dental amalgams.

Mercury release from dental amalgams has generated considerable concern in recent years and is the subject of this study. Specimens of one admixed high-copper amalgam (Contour), one lathe-cut low-copper amalgam (SDI), and a new tin- and copper-free amalgam claimed to be non-mercury-releasing (Composil) were evaluated for release of mercury when incubated in purified water at 37 degrees C. Measurement of mercury was done by cold-vapor atomic absorption spectrophotometry, and the amount released was expressed as micrograms/cm2/24 hr. Study was conducted over a four-week period. Results show that Contour and SDI released similar insignificant amounts (mean release of less than 0.1 microgram/cm2/24 hr) compared with Composil (mean release of 41.0 micrograms/cm2/24 hr). The difference in release by Composil compared with that by Contour and SDI is highly significant (P less than 0.001). The implications of chronic release of mercury from dental amalgams are discussed. Long-term release studies are in progress.

Dental Amalgam↗
PubMed1989

Gluma dentin adhesive: effectiveness and shelf life.

The purpose of this study was to test the effectiveness and shelf life of a commercially available glutaraldehyde/methacrylate dentin adhesive (Gluma). The measurement of marginal contraction gaps in 320 cavities restored over a period of 415 days was the basis for these determinations. The results showed that Gluma dentin adhesive was more effective with one of the two composite restorative materials used for the study, and that the shelf life of Gluma exceeded 415 days.

Aldehydes↗