Caries experience and related factors in 4-6 year-olds attending dental clinics in Kinshasa, DR of Congo.

OBJECTIVES: The aim of this study was to examine the prevalence and severity of caries experience (CE) in 4-6 year-olds attending dental clinics in Kinshasa, DR Congo, and to explore possible associations with reported behavioural and socio-demographic factors. METHODS: A convenience sample of children attending five dental clinics was recruited. Carers, usually parents, completed a questionnaire consisting of socio-demographic information, oral health and tobacco consumption profile of parents, socio-economic family situation and oral health habits of the child. Children were clinically examined using WHO criteria by trained dentist-examiners. To investigate factors associated with CE, multivariate logistic regression was applied with the significance level set at 0.05. RESULTS: Some 158 children with mean age 5.3 (sd 0.7) years were recruited; 80% presented with clinical signs of CE. Between-meal snacking and drinking was reported by 78% and 65%; 35% had sugar-containing drinks. Most (81%) brushed once a day and 82% brushed in the morning. Prevalence of CE was associated with gender, frequency of meals, consumption of drinks during meals and consumption of sugar-containing drinks; severity with type of infant feeding and sugar-content of the last meal at night. CONCLUSION: The present study shows that both prevalence and severity of caries experience were associated with reported dietary habits, confirming the importance of preventive interventions dealing with these habits in young children living in a developing country.

Caries risk management: effect on caries incidence in a sample of Lebanese preschool children.

OBJECTIVES: This clinical prospective study describes how caries preventive measures applied according to caries risk affect new caries incidence in a group of preschoolers, as compared to a group where standardized caries prevention is applied, regardless of risk. METHOD AND MATERIALS: Healthy children, aged four years or less, recruited at the Faculté de Médecine Dentaire, Université Saint-Joseph, Beirut, Lebanon were assigned, after parental consent, to an experimental or a control group. Caries risk was determined based on a parental questionnaire, salivary levels of Steptococcus mutans (Sm) and Lactobacillus (Lb), salivary buffer capacity, plaque levels and carious lesions prevalence, then subjects were classified into four caries risk categories. In the experimental group, preventive measures designed for each risk category were applied periodically, whereas control subjects received only standardized preventive measures at regular intervals. All subjects were reevaluated for Sm, Lb, salivary buffer capacity, plaque and new carious lesions after 24 months. RESULTS: Statistically significant reductions in salivary Sm (p=0.001) and Lb (p=0.003) levels, plaque scores (p=0) and caries incidence (p=0.003) were observed in the experimental group. In the control group, no significant differences were observed between initial and final Sm (p=0.18) and Lb (p=0.109) levels or plaque scores (p=0.255), and caries incidence was not significantly reduced (p=0.584). CONCLUSION: The present study's results suggest that caries preventive measures applied according to caries risk may reduce caries risk factors and new caries incidence in preschool-aged children. These findings deserve further investigation to benefit early childhood caries prevention on a larger scale.

Caries prevalence and caries risk in a sample of Lebanese preschool children.

OBJECTIVES: This study describes early childhood caries prevalence and caries risk in a group of Lebanese preschoolers. METHOD AND MATERIALS: 99 healthy children, aged four years or less, were recruited at the Dental medicine faculty, Saint-Joseph university, Beirut, Lebanon. After parental consent, questionnaires investigated children's dietary and oral hygiene habits and parents' education and health behaviors. Oral examinations, with bite-wing radiographs when necessary, determined decayed-filled surfaces and plaque scores. Salivary testing assessed buffer capacity and streptococcus mutans (Sm) and lactobacillus (Lb) presence. The three tests (questionnaire, oral examination, salivary testing) established a caries risk assessment tool, determining subjects' caries risk scores, classified as low (C0), moderate (C1), high (C2) or very high (C3). RESULTS: 25.3% of subjects were caries-free, 24.2% had 4 carious lesions or less, 28.3%, 5 to 9 lesions and 22.2% over 10 lesions. 11.1% of plaque scores were low to mild, 18.2% moderate, 46.4% high, and 24.3% very high. Salivary buffer capacity was: 29.3% high, 57.6% medium and 13.1% low. High levels of Sm, (66.7%) correlated with plaque presence and proximal caries. High levels of Lb (52.5%) correlated with plaque presence and smooth-surface caries, and correlated significantly with occlusal caries. Regular tooth brushing yielded lower plaque, but not significantly lower caries levels. Systemic fluorides were associated with lower plaque and caries scores. Children of educated parents with regular dental visits and oral hygiene had lower plaque and caries scores. Caries risk distribution was: CO: 16.2%, C1: 29.3%, C2: 15.1% and C3: 39.4%. CONCLUSION: Most subjects had at least one carious lesion (74.7%), and 70.7% showed high to very high plaque scores. Over half the sample presented high or very high caries risk. These findings deserve further investigation of the Lebanese preschoolers' population.

[Chemical and traumatic irritation of a canine premolar tooth germ]. / Irritations chimique et traumatique d'un germe de prémolaire de chien.

The arrest of a premolar bud was observed in an animal experiment that was designed to study the influence of endodontic treatment in dogs' temporary teeth on the eruption of their permanent successors. A chemical irritation was induced by the burst of ZOE (zinc oxide and eugenol) into the dental follicle. Moreover, a mechanical trauma on the temporary molar was promoted by the dog's biting on its cage metallic bars. The devitalization effects were studied in thick undecalcified ground sections which were subjected to microradiographic analysis, to UV light microscopy in order to detect the fluorescent indicators of calcification, and finally to methylene blue staining. The arrest of the bud development was noted in fluorescent microscopic examination. Cellular cementum was formed on the pulpal surface of the dentine, while cementum, chondroid tissue, woven bone and lamellar bone developed in the pulpal tissue. These observations advise caution during root canal therapy of temporary teeth, especially those that are exposed to mechanical trauma. Such as the upper incisors.

[A 24 month evaluation of zinc oxide pulpotomy on primary canines]. / Evaluation sur 24 mois de la pulpotomie à l'oxyde de zinc-eugénol sur des canines temporaires saines ou cariées.

Pulpotomy is the most performed and controversial therapeutic in pediatric dentistry. Since formocresol is known to have a toxic effect on living tissues, plus a mutagenic and carcinogenic potential with a systemic uptake of formocresol via pulpotomized teeth, other alternative products have been investigated. Twenty-five decayed primary canines and twenty-five healthy primary canines necessitating disking for orthodontic purposes were pulpotomized using non modified Zinc Oxide Eugenol. The effects of this material were evaluated both clinically and radiographically. Post operative control examinations were performed at 1, 6, 12, and 24 months trying to detect spontaneous or stimulated pain, pathological tooth mobility, abscesses or fistulas, internal or external pathological tooth resorption, periapical bone destruction, or canal obliteration. Pain was absent at 24 months post operatively. Half of the treated canines presented with a mobility, while internal and external resorptions were more frequent in decayed teeth and their number increased with time. On the other hand, abscesses and fistulas were equally found in both treated groups. The observations were compared to others related to formocresol ferric sulfate, MTA, and laser pulpotomies, using the binominal law, or the comparative test of an observed proportion to a reference proportion. In this study, and based on the excessive negative results in both groups, we demonstrated that non fixative pulpotomies on temporary canines were not a promising technique.

[The limits of conservative care in pedodontics]. / Les limites des soins conservateurs en pédodontie.

Despite progress in the decrease of caries by means of many preventive dental programs, children's teeth of poor socio-economic groups are still strongly affected. The well known role of children's teeth in oro-facial growth and harmony, as well as in the development of functions as chewing, speaking or phonation and swallowing, has justified their preservation during all their functional periods. Several conservative therapies allow to reach this purpose. However, extensive dental caries, difficulty to get child tooth infection under control, injuries on permanent tooth germs and child's general health deficiency, can limit preservation of infected teeth, leading to their extraction.

Microradiography and fluorescence microscopy of bone remodeling on the basal crypt of permanent mandibular premolars in dogs during eruption.

Alveolar bone of erupting teeth was studied in order to define the types of calcified tissues deposited as well as the rate of tooth growth. The third (P3) and fourth (P4) mandibular premolars of 30 dogs aged 12-24 weeks were analyzed by microradiography and microscopy in fluorescent and ordinary light. The bone plate separating P3 and P4 from the mandibular canal presented a complex arrangement of lamellar and woven bone, and even of chondroid tissue. During the pre-eruptive phase, this plate shifted towards the base of the mandible by means of selective resorption and apposition activities. As soon as the furcation was formed, bone apposition appeared on the alveolar side and became the main activity under P3 at the outset of eruption. Under the roots of P4 it occurred 4 weeks later. Dynamic morphometry in fluorescence microscopy showed that eruption progressed faster than the radicular growth. The formation of interradicular bone underwent the same acceleration as the eruption. However, though the tissues were formed at a high rate, it cannot be inferred therefrom that they are responsible for tooth shifting. They might just fill the space left by the erupting tooth.

Microradiographic aspects of the growing mandibular body during permanent premolar eruption in the dog.

In order to explore the bony changes in the mandibular body during prefunctional intraosseous eruption of premolars, 18 dogs aged from 8 to 16 wk at the beginning of experimental period, were given two intraperitoneal injections of oxytetracycline (50 mg/kg and 35 mg/kg 2 wk later) and 2 wk later a final injection of Alizarin red S (70 mg/kg). Microradiographic and fluorescent light microscopy studies showed that changes of the alveolar bony crypt walls were influenced by the growing dental germs which they surrounded. The cervical volumetric reduction, which indicates the end of crown formation, induced the apposition of lamellar and then woven bone on the adjacent alveolar walls. Furthermore, with occlusal displacement of the dental crown, the space below the tooth was immediately filled with woven bone trabeculae and chondroid tissue. The same phenomenon was observed at the level of the alveolar base, when the speed of tooth eruption was greater than that of root growth. During premolar development, the changes in the dental germ produces accommodating changes in the adjacent alveolar bone walls, and mandibular transversal growth has the same characteristics as that of a growing diaphysis.