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Biomedical subjects

P Cleaton-Jones

Publications and source records attributed to P Cleaton-Jones.

At least 19 recordsLinked to original sources
PubMed2005

Global trends in dental fluorosis from 1980 to 2000: a systematic review.

AIM: To determine trends in fluorosis prevalence at water fluoride levels <0.3, >0.3 to <0.7, and >0.7 to 1.4 ppm from 1980 to 2000. METHODS: A systematic review of 55 published articles identified in a Medline search for peer-reviewed articles on fluorosis published from 1 January 1980 to 31 December 2000. The prevalence recorded with any fluorosis index was pooled and the trends over time were determined in the three water concentration categories. RESULTS: The fluorosis prevalence for the three fluoride categories were 16.7, 27.4 and 32.2 percent, respectively. A 16-fold and a 2-fold increase in fluorosis prevalence compared with reported rates in the 1940s was seen in non-fluoridated (= 0.3 ppm F) and fluoridated (>0.7 to = 1.4 ppm F) areas, respectively. There has been an increase in fluorosis prevalence over time in the three fluoride water concentration categories but linear regression analysis showed that none are significantly different from zero. CONCLUSION: This systematic review concurs with recent reports of an increase in fluorosis prevalence in fluoridated and non-fluoridated communities.

Analysis of Variance↗
PubMed2004

Pulpitis induction in baboon primary teeth using carious dentine or Streptococcus mutans.

The objective of this equivalency study was to see if a colony of Streptococcus mutans placed into cavities in primary molar teeth produced pulpitis similar to an established pulpitis induction method using carious dentine. In two juvenile baboons (Papio ursinus), occlusal cavities were cut in all 16 primary molar teeth, followed by making a small pulpal exposure after which the cavity was swabbed with 37 per cent phosphoric acid. In one half of the teeth, fresh soft human carious dentine was placed over the pulpal exposure; in the remaining teeth the exposure was covered with a colony of Streptococcus mutans in agar. All the cavities were restored with unlined light-cured composite resin. After 14 days specimens were harvested and examined under the light microscope with the examiner blind to the induction method. In both groups of teeth there was recognisable pulp, hyperaemia, micro-abscesses in the pulp and peri-apical abscesses. Reactions to soft caries were more severe than to Streptococcus mutans. The results show that Streptococcus mutans placed in a cavity with an exposure produces comparable pulpitis to fresh soft human carious dentine in the same type of cavity and that both methods produce pulpitis suitable for testing pulpotomy or pulpectomy treatments.

Abscess↗
PubMed2004

Zinc oxide-eugenol and calcium hydroxide pulpectomies in baboon primary molars: histological responses.

AIM: To compare histological responses to zinc oxide-eugenol (ZOE) and calcium hydroxide (CH) pulpectomies in primary molar teeth with inflamed pulps. STUDY DESIGN: This was an experimental study in 17 juvenile baboons (Papio ursinus). METHODS: Pulpitis was induced with fresh human carious dentine or Streptococcus mutans placed into occlusal cavities in 78 primary molars; after 14 days a pulpectomy was performed on the same primary molars with the two root fillings randomly allocated. The root canal openings were then covered with IRM and the cavity filled with amalgam. After 90 days specimens were harvested and examined under the light microscope with the examiner blind to the treatment. RESULTS: Reaction frequencies in the ZOE-treated versus CH-treated teeth were: no recognisable pulp 89% and 82%, internal root resorption 0% and 1%, external root resorption 11% and 24%, presence of bacteria 5% and 18%, periapical abscesses 24% and 52%. STATISTICS: Fisher's exact probability test showed a statistically significant higher prevalence of periapical abscesses in the CH-treated group (P=0.03, relative risk 2.2). CONCLUSIONS: ZOE pulpectomy is preferred to CH for the treatment of infected pulps in primary molars.

Animals↗
PubMed2002

Ferric sulphate and formocresol pulpotomies in baboon primary molars: histological responses.

AIM: To compare pulpal reactions to ferric sulphate and formocresol pulpotomies in primary molar teeth with inflamed pulps. STUDY DESIGN: An experimental study in 15 juvenile baboons (Papio ursinus). MATERIALS AND METHODS: Pulpitis was induced with fresh human carious dentine or Streptococcus mutans placed into occlusal cavities in 57 primary molars; after 14 days a pulpotomy was performed on the same primary molars with the two pulp medicaments randomly allocated; the pulp was covered with IRM and the cavity filled with amalgam. After 90 days specimens were harvested and examined under the light microscope with the examiner blind to the treatment. RESULTS: Reaction frequencies in the ferric sulphate-treated and formocresol-treated teeth were: recognisable pulp 52% and 50%, dentine bridges 16% and 12%, internal root resorption 12% and 4%, external resorption 28% and 31%, bacteria 12% and 23%, peri-apical abscesses 32% and 38%. STATISTICS: Fisher's exact probability test showed no statistically significant differences between reaction frequencies in the two treatment groups. CONCLUSION: A pulpotomy in a primary tooth may be clinically successful in the presence of adverse histological reactions.

Journal Article↗
PubMed2001

Clinical crown height (length)--a review of published measurements.

BACKGROUND, AIMS: Clinical crown height is an objective measure of the position of the gingival margin which could be used in determining the 'normal' position of the gingival margin. The aim of this study was to do a systematic review of published clinical crown heights in the human permanent dentition to compare the measurements and to see if a clear trend with age exists. MATERIAL AND METHODS: An on-line literature search was done using the key words clinical crown height (or) clinical crown length. From January 1975 to August 2000, 11 published papers have listed measurements; three of these report on all tooth types, the remainder on anterior teeth. RESULTS: All studies used the same measuring technique but age group reporting differed as did the tooth types measured. Measurements from the 10 acceptable studies of the clinical crown height of the same teeth are comparable at similar ages, so published values are reasonable estimates of 'normality' for diagnosis. There is a statistically significant increase in clinical crown height of central and lateral incisors with age that slows as age increases.

Age Factors↗
PubMed2001

Examiner performance with visual, probing and FOTI caries diagnosis in the primary dentition.

To compare clinical reproducibility of dental caries diagnosis in the primary dentition under field conditions, a convenience sample of 5-year-old children in a nursery school in Germiston, was examined for dental caries by four dentists using visual (mirror), visual plus tactile (mirror plus probe) and fibre-optic transillumination (FOTI) methods. Seventeen children were examined on day one and 11 re-examined on day two. Inter-examiner agreement was high, above 90%. Visual examination on its own is comparable with the traditional visual plus tactile method and to FOTI under field conditions. New caries data collected by visual diagnosis alone may, reasonably, be compared with historical data diagnosed with visual + tactile examination.

Chi-Square Distribution↗
PubMed2001

Dental caries trends in 5 to 6 year-old and 11 to 13 year-old children in two UNICEF designated regions: Sub-Saharan Africa, and Middle East and North Africa, 1970-2000.

The purpose of this study was to do a systematic review of published caries epidemiology studies in two UNICEF defined regions, Sub-Sahara Africa, and the Middle-East and North Africa that contain 63 developing countries. On-line searches were made of articles listed in Medline using PubMed to investigate trends in dental caries in 5 to 6 year-old, and 11 to 13-year-old children using defined inclusion criteria. Of 493 listed publications, 70 fulfilled the inclusion criteria. The percentage caries rates and mean dmft, as well as mean DMFT scores, were plotted against study year. Non-significant percentage caries prevalence trends were downward in Sub-Saharan Africa for both 5-6 year-olds and 11-13 year-olds while in Middle-East and North Africa caries prevalence remained constant over the 30-year review period in both age groups. Mean dmft scores significantly diminished in 5-6 year-olds during the study period (y = 200-0.1x, P = 0.05) in Sub-Saharan Africa but the scores remained constant in the Middle-East and North Africa. Mean DMFT scores remained constant in 11-13 year-olds in both Sub-Saharan Africa and the Middle-East and North Africa. When the mean dmft and DMFT scores per carious mouth were calculated both age groups in Sub-Saharan Africa showed clear reductions, that for 11 to 13 year-olds was statistically significant (y = 170-0.084x, P = 0.014). In the Middle-East and North Africa the trends in the two age groups remained unchanged.

Adolescent↗
PubMed2001

How does zinc oxide-eugenol compare to ferric sulphate as a pulpotomy material?

This study compared the clinical and radiographic responses after 3 months to a sterile compression technique with zinc oxide-eugenol or 15.5% ferric sulphate in 145 pulpotomised primary teeth in 30 children. In both groups of teeth the success rate was 100%. These short-term results suggest that either technique may be used.

Child↗
PubMed2000

Surveillance of primary dentition caries in Germiston, South Africa, 1981-97.

OBJECTIVE: This 17-year-long study examined trends of dental caries rates in the primary dentition of 6843 preschool children in a South African city. METHODS: Calibrated dentists did repeated cross-sectional epidemiological surveys of dental caries in 2- to 5-year-old nursery school children using WHO diagnostic criteria between 1981 and 1997. RESULTS: Both the percentage of children with dmft>0 and mean dmft increased between 1981 and 1989 and have slowly declined ever since in the absence of organised prevention to produce a secular trend of decreasing caries rates. The dt/dmft percentage ranged between 60% and 100% except in 1991 when it dropped to 40% and the ft/dmft percentage component rose proportionally, probably due to an economic effect. CONCLUSIONS: The percentage of children with dmft>0 and mean dmft decreased over the study period at all ages, the reason for which is unknown but is speculated to be due to a change in mutans streptococci strains.

Black or African American↗
PubMed2000

Oral health in Hlabisa, KwaZulu/Natal--a rural school and community based survey.

AIMS: To investigate rates of dental caries and periodontal disease, available dental services and resources and perceived needs in a rural South African community. DESIGN: A cross-sectional field study including situational analysis and focus group discussions. SETTING: KwaZulu/Natal, South Africa. PARTICIPANTS: A total of 520 children, adolescents and adults. METHODS: WHO caries scores and periodontal CPI score were determined through clinical examinations in five age groups, 5-6 years, 12 y, 15 y, 35-54 y, 55 y+. Focus groups included ten 15-year-old children and ten adults. RESULTS: Caries prevalences and (mean scores) were 5-6 y 64% (dmft 3.0), 12 y 24% (DMFT 0.4), 15 y 27% (DMFT 0.8), 35-54 69% (DFT 2.6) and 55 y+ 80% (DFT 2.7). Most caries was untreated and where present, treatment had been extraction. Dental caries rates were low and except for 5-6 y were within WHO targets for the year 2000. Periodontal disease prevalence was high but would respond to improved oral hygiene. Knowledge of oral health was rudimentary. CONCLUSIONS: A district-wide oral health promotion programme is required preceded by research to define effective health education messages. Access to simple but effective preventive and curative services would seem reasonable. In view of the lack of resources ART is suggested as caries treatment.

Adolescent↗
PubMed2000

Nutritional status and dental caries in a large sample of 4- and 5-year-old South African children.

BACKGROUND: Evidence from studies involving small samples of children in Africa, India and South America suggests a higher dental caries rate in malnourished children. A comparison was done to evaluate wasting and stunting and their association with dental caries in four samples of South African children. DESIGN: Cross-sectional study based on random sampling of birth records of two age bands. METHODS: A total of 2,728 4- and 5-year-old South African children from one rural community and three urban communities were examined for nutritional status and dental caries. RESULTS: In the total sample prevalences of wasting were mild (28%), moderate (4%) and severe (2%). For stunting the prevalences were mild (13%), moderate (3%) and severe (1%). For both conditions rural children showed higher proportions than the other groups. Statistical analysis showed statistically significant differences for wasting and stunting between the study groups. No significant association was found between the prevalence of caries and stunting or wasting, but an association was noted between wasting and decayed, missing and filled (dmf) surfaces (P = 0.003). CONCLUSIONS: In the series of children studied, nutritional status was not found to be clinically relevant to dental caries prevalence and experience.

Child Nutrition Disorders↗
PubMed1999

Dental caries trends in Africa.

OBJECTIVES: To determine trends in published dental caries rates in Africa. METHODS: A systematic review of published information 1967-1997 was done on-line with the key words dental caries and the name of each of the 35 countries in sub-Saharan mainland Africa. For inclusion in the analysis WHO methods had to have been used for 5- to 6-, 11- to 13-, 14- to 15- and 35- to 44-year-old indigenous Africans. RESULTS: Of 327 papers published in the study period 69 were proper epidemiological studies and 45 fulfilled inclusion criteria. The groupings of caries prevalence and severity were evaluated. In two, significant declines in caries severity were seen for 5- to 6- and 35- to 44-year-olds. Of the remaining eight groupings there were non-significant decreases in five and increases in three. CONCLUSIONS: The study showed a predominantly downward trend in dental caries which was statistically significant for DMFT at age 5 to 6 years and for DMFT at 35 to 44 years.

Adolescent↗
PubMed1997

Relative displacement resistance of standard and low-profile bone plates in experimental mandibular angle fractures.

OBJECTIVE: The purpose of the study was to compare the resistance to displacement of low-profile and standard titanium bone plate with an experimental mandibular angle fracture model. STUDY DESIGN: A jig was used to produce standard horizontally and vertically unfavorable mandibular angle fractures in 24 healthy baboon hemimandibles. Each hemimandible was immobilized with either a standard or a low-profile titanium bone plate with a Champy unicortical technique. The resistance to displacement was measured in a tensile-testing machine, and results were analyzed with a three-way analysis of variance. RESULTS: Mean (SD) forces required to displace the fractures were standard plate 68.7 (22.8) kg and low-profile plate 46.5 (24.6) kg. CONCLUSIONS: The standard plates provided significantly more resistance to displacement, and 75% of the low-profile plates fractured through a screwhole.

Animals↗
PubMed1997

A histological and quantitative histomorphometric study of apexification of nonvital permanent incisors of vervet monkeys after repeated root filling with a calcium hydroxide paste.

The purpose of this study was to compare the effect of a monthly refilling of the root canals with calcium hydroxide paste with a single packing or replacement of the paste at 3 months on the apexification of nonvital maxillary incisors of vervet monkeys. Forty-eight maxillary incisors from 12 monkeys were used following radiographic determination that root development was incomplete. The pulps were extirpated under general anesthesia and the root canals filed and cleaned. The root canals were filled with a commercial calcium hydroxide paste, Calxyl, and a temporary cavity filling placed. Twelve teeth were left without further treatment. The calcium hydroxide paste was replaced in 12 teeth after a 3-month interval, and in the remaining 24 teeth the calcium hydroxide root filling was replaced five times at monthly intervals. The monkeys were killed after 6 months, and blocks of the teeth and surrounding tissues were embedded, decalcified and 6 microns serial sections prepared and stained. The sections were studied histologically to evaluate 11 parameters. Significant differences were found in the amount of calcium hydroxide at the apices, the presence of new cementum on the roots and the degree of inflammation, all of which were better in the monthly refill group. Histomorphometric measurements to evaluate the obturation of the open apices and the volume of new primary osteocementum showed no significant difference between the three groups. It was suggested that after the initial root filling with calcium hydroxide there was nothing to be gained by repeated root filling either monthly or after 3 months, for at least 6 months.

Analysis of Variance↗
PubMed1997

The plaque acidogenic response to carbohydrates of children from three ethnic groups in South Africa.

The plaque acidogenic response of children from three ethnic groups in South Africa to four different carbohydrates was investigated using the plaque sampling method. A total of 30, 12-year-old children, ten black, ten 'coloured' and ten white, completed this study. The foods tested were 10 per cent sucrose solution, maize porridge, strawberry flavoured yoghurt and banana. The blacks produced an intermediate plaque pH response to sucrose compared with the 'coloureds' and whites but the smallest response for the other carbohydrate challenges. It was concluded that a difference exists in the plaque acidogenic response to carbohydrate between the three ethnic groups and that this may in part account for differences in caries prevalences.

Acids↗
PubMed1997

A comparison of three electrodes for the measurement of pH in small volumes.

An ion-sensitive field effect transistor (ISFET, Sentron, Sentron, Inc.) electrode was compared with a glass combination micro-electrode (MI-410, Micro-electrodes, Inc.) and a solid-state metal wire oxide pH sensor (Beetrode, World Precision Instruments, Inc.) with a liquid junction reference electrode (MERE1, World Precision Instruments, Inc.). The electrodes were assessed for linearity, reproducibility, accuracy, drift from the initial calibration between pH 4 and pH 7 and the time taken to record a stable reading. The ISFET was used to determine the pH in dental plaque samples (1 mg suspended in 20 microliters). The pH values correlated with the hydrogen ion concentration for all the electrodes (r = 0.98). The MI-410 fractured before this evaluation was completed. Coefficients of variation were 0.65% (pH 4) and 0.08% (pH 7) for the ISFET and 4.69% (pH 4) and 3.46% (pH 7) for the Beetrode. Both electrodes gave readings that differed significantly from the initial calibration, but the drift was greater for the Beetrode (F = 7.93; p = 0.0005) than the ISFET (F = 1.89; p = 0.1519). However, this drift was smaller than the change in pH as measured in dental plaque samples. The Beetrode gave a stable reading after 3.39 +/- 0.83 s and the ISFET after 2.2 +/- 0.76 s, while the MI-410 required at least 20 s. The ISFET type electrode is suitable for use in small volumes such as plaque suspensions, is easier to operate and yields results closer to the initial calibration than the Beetrode and is more robust than the MI-410 and the Beetrode.

Analysis of Variance↗
PubMed1996

Tooth surface and pulp chamber temperatures developed during electrothermal bonding.

The rationale of electrothermal bonding is based on the premise that when an electric current is passed across the beaks of tweezers holding a stainless steel orthodontic bracket, heat will be generated by virtue of the electrical resistance of the steel bracket. This study was carried out to evaluate the temperatures generated on the tooth surface at the bracket/tooth interface and within the pulp chamber during electrothermal bonding. Temperatures were recorded with 5 and 7.5 A current levels applied as a 1 second pulse with time intervals between pulses of 1, 2, 3, and 4 seconds. The data showed that after three pulses with a 5 A current, the temperature on the tooth surface ranged between 43.3 degrees C (4 second intervals) to 53.6 degrees C (1 second intervals). By using a 7.5 A current, the temperature ranged from 77.5 degrees C (4 second intervals) to 85.9 degrees C (1 second intervals). The pulp chamber temperatures were evaluated in vitro for a mandibular incisor, the maxillary central and lateral incisors, a canine, a premolar, and a molar. The pulp chamber temperature of a mandibular incisor responded most, whereas that of premolars and molars responded least to temperature changes on the labial surface. The increase in mandibular incisor pulp chamber temperature after three pulses was 2.1 degrees C for 5 A and 2.8 degrees C for 7.5 A current while for a premolar the increase ranged from 0.9 degree C to 1.6 degrees C. On the basis of current evidence the increase in pulp chamber temperatures during electrothermal bonding may be considered to be clinically safe.

Bicuspid↗