Acidogenic fermentation of pentose alcohols by human dental plaque microorganisms.

The potential non-cariogenicity of the pentose sugar alcohols xylitol, l-arabinitol and ribitol was estimated by determining their fermenting properties with 50 separate samples of dental plaque, collected from people of different ages. Sucrose and control cultures were included for comparison. For most subjects, sucrose was more acidogenic than the pentitols. Lactobacilli or propionibacteria which fermented xylitol were isolated in pure culture from 2 out of 50 plaque samples whereas lactobacilli which fermented l-arabinitol were purified from another. Tests were made for pentitol metabolism by saliva collected from 8 subjects: 3 carried lactobacilli or propionibacteria which fermented xylitol and at least 2 contained lactobacilli that used l-arabinitol anaerobically. Candida albicans isolated from 2 subjects metabolized xylitol aerobically. Thus xylitol-utilizing oral microorganisms may be widespread. Further research is desirable before encouraging the widespread substitution of xylitol for sucrose.     

Severe proliferative congenital temporomandibular joint ankylosis: a proposed treatment protocol utilizing distraction osteogenesis

The classical treatment for temporomandibular joint (TMJ) ankylosis in children: 1) joint release; 2) arthroplasty; 3) reconstruction; and 4) postoperative physical therapy (PT), is often unsuccessful. Postoperative physical therapy is difficult in the young patient due to poor cooperation. Moreover, there is a subgroup of patients who have a refractory congenital proliferative bony process that is the cause of their disease. In these patients, a role for distraction osteogenesis (DO) has been defined. We present a series of young patients with congenital proliferative TMJ ankylosis. Some have failed classic treatment. In such cases, DO is used to expand the mandibular size and soft tissue matrix. This creates a static open bite, facilitates mid-facial growth, and avoids compromise of the airway, speech, nutrition, and oral hygiene. To maintain these objectives, mandibular DO may be repeated as the child matures. Once skeletal maturity is reached, DO is used to normalize occlusion and further expand the soft tissue envelope prior to definitive reconstruction and aggressive post-op PT. In seven patients, this protocol has been used. Five patients are currently in the active phase of growth and undergoing interim treatment with mandibular DO. Two patients have reached skeletal maturity and have completed the protocol of DO with definitive arthroplasty and reconstruction. DO is a valuable aid in the treatment of the problematic child with congenital proliferative TMJ ankylosis. Interim DO, prior to definitive arthroplasty and reconstruction, can provide a static open bite that prevents progressive deformity and its associated functional disturbances.     

Dental caries prevalence and dental health behaviour in HIV infected children

Objectives . To determine dental caries prevalence in a group of HIV positive children and their reported dental health behaviour.
Design . Standardized epidemiological dental examination and structured interview.
Setting . Paediatric HIV outpatient department in a South London hospital.
Study population . HIV-positive children attending the above outpatient clinic over a 6-month period (30 subjects) and parents (20 informants).
Methods . Epidemiological examination of children was undertaken by one trained and calibrated examiner to determine caries prevalence using dmft/DMFT. Parents were interviewed to obtain information on their children's dental health behaviour: tooth-brushing, diet, fluoride; oral medication and dental attendance were explored.
Results . Sixty-three per cent ( n  = 19) of children had dental caries experience, much of it untreated. Mean dmft/DMFT was 4·4. Sixty per cent ( n  = 18) of all children presented with active or untreated caries and the care index for those at/under age 5 years was low (10%). Unfavourable dental health behaviour included: consumption of nonmilk extrinsic sugars at night, use of sugar-based medications, low fluoride intake, late commencement of toothbrushing and poor dental attendance. Dental health was not considered a priority for many of these children. Parents did not necessarily disclose their child's HIV status on dental attendance.
Conclusion . Caries prevalence was high, much of the disease untreated, and unfavourable dental health behaviour, including the use of sugar-based medicines was common. HIV infected children should be considered a high caries risk and receive appropriate dental care, in terms of both treatment and preventive services, following confirmation of seropositivity.     

Alterations of surface hardness with gypsum die hardeners

STATEMENT OF PROBLEM: Die stones require abrasion resistance, dimensional stability with time, and high surface wettability material properties. PURPOSE: The purpose of this study was to compare the surface microhardness (Knoop) of 4 contemporary gypsum materials with and without surface die hardener. MATERIAL AND METHODS: Materials used were a Type III stone (Microstone) and 3 die stones (Die-Keen, Silky-Rock, and ResinRock). Die hardener was cyanoacrylate (Permabond 910) or Clear Coat. Specimens of stone were hand mixed with distilled room temperature water and vacuum spatulated according to manufacturer's directions. Five cylinders (15 x 15 mm) per group were poured, using vibration, into phenolic ring molds positioned on top of a glass slide. The face of each specimen was polished with 2400-grit Al2O sandpaper. One face of each of 5 specimens/material was coated with cyanoacrylate; 5 specimens/material were coated with Clear Coat, air thinned and dried; and 5 specimens/material had no treatment (control). Knoop hardness (kg/mm2) readings were made on each face (5 readings/time point) 3, 12, and 24 hours after pouring. An ANOVA procedure with post hoc Tukey tests were performed (alpha=.05). RESULTS: Microhardness did not vary between 3 and 24 hours for any material (P>.05). Microstone had significantly lower surface hardness (P<.0001) than the die stones. Specimens coated with die hardener had lower hardness values (P<.001 in all cases) CONCLUSIONS: The 3 types of die stones evaluated in this study did not differ significantly in surface microhardness. Under these conditions, die hardener coatings reduced the surface hardness of the gypsum material.     

Associations of serum concentrations of IgG,IgA, IgM and interleukin-1beta with early-onset periodontitis classification and race

BACKGROUND: The significance of serum concentrations of various antibodies and cytokines in the pathogenesis of early-onset periodontitis (EOP) is not well understood. Recent reports suggest differences between young blacks and whites in certain humoral responses, regardless of periodontal status. This study was undertaken to compare the serum concentrations of IgG, IgA, IgM, and IL-1beta in EOP subjects with that of healthy controls, and to study the effect of race on these levels. MATERIAL AND METHODS: This case-control study included 228 individuals, 19-25 years old who were selected from a larger population examined in the National Survey of Oral Health of United States Children in 1986/1987. The subjects were classified by their EOP status and they included 166 subjects with EOP and 62 healthy controls. Blood samples were used to assess the serum concentrations of IgG, IgM, IgA, IgG subclass, and IL-1beta. RESULTS: The serum concentrations of IgG, IgG subclasses, IgA, and IgM in blacks were not significantly different in the generalized, localized and incidental EOP groups as compared to the healthy controls. The serum IL-1beta concentration was slightly and uniformly lower in the EOP groups than in the control group, although not statistically significant. Blacks had significantly higher serum concentrations of total IgG, and of IgG1, IgG2 and IgG3 than whites and Hispanics. Hispanics had significantly higher serum concentrations of IgM and IgG4 than whites and blacks. Hispanics also had a significantly higher serum concentration of IL-1beta than blacks. CONCLUSIONS: Total antibody response in blacks is not associated with EOP classification. Race has a significant effect on serum antibody concentrations irrespective of disease classification, with blacks having significantly higher serum concentrations of IgG1, IgG2 and IgG3 than whites and Hispanics.     

Prosthetic assessment in the treatment of denture hyperplasia.

The removal of denture-induced trauma is important in the treatment of denture hyperplasia and in the prevention of its redevelopment in susceptible patients. A simple approach to the assessment of dentures is described, which highlights potentially damaging areas of the borders and the fitting surface.     

A transcultural perspective on the emotional effect of tooth loss in complete denture wearers

PURPOSE: The purpose of this study was to compare the emotional effects of tooth loss in three edentulous populations. MATERIALS AND METHODS: A questionnaire study involved 142 edentulous subjects undergoing routine prosthodontic care at Guy's, King's and St Thomas's Dental Institute, London; the Dental School, Dundee, Scotland; and the Faculty of Dentistry, University of Hong Kong. Data were analyzed using the chi-squared test. RESULTS: Difficulty in accepting tooth loss was a relatively common experience (44%) in all groups, with almost half feeling that their confidence had been affected. The majority (66%) felt that their choice of food was restricted and that the overall eating experience was less enjoyable, particularly the Hong Kong group. A significant proportion of the participants were concerned about their appearance without dentures, although the trend was less marked in Hong Kong. Forty-three percent felt that they were not adequately prepared for tooth loss, although the Hong Kong group was least concerned. CONCLUSION: In general, the emotional effect of tooth loss was significant in all groups. The restrictions on daily activities were generally greater in the Hong Kong group. However, this group was much less inhibited by denture wearing. The differences observed in the Hong Kong Chinese are most likely due to different cultural values and expectations associated with these aspects of daily living.