Search PubMed⌕ Search

Biomedical subjects

W E van Amerongen

Publications and source records attributed to W E van Amerongen.

At least 19 recordsLinked to original sources
PubMed2006

Iatrogenic damage to the adjacent surfaces of primary molars, in three different ways of cavity preparation.

AIM: A clinical study was carried out to compare three methods of preparing a cavity regarding the measure of damage to adjacent teeth: the ART method, the use of the latest version of Carisolv and as a control group the use of rotating instruments. METHODS: Preparations (217) were made by 2 Tanzanian dentists and 2 final year Dutch dental students at the Muhimbili University College of Health Science (MUCHS) in Dar es Salaam, Tanzania. Only children 7 years old, with one class II cavity in a primary molar and no dental experience were included in the study. After cavity preparation, partial impressions of the adjacent teeth were made, from which resin models were cast and later studied under a stereomicroscope. RESULTS: These showed damage of 91.7% in the Bur group, which was significantly greater than in the ART and Carisolv groups (62.7% and 59.5% respectively). CONCLUSION: Protection of the adjacent surfaces is necessary, for instance in the form of matrix band separation and by means of damage reducing techniques. More studies on the long term effect of the damage need to be conducted.

Child↗
PubMed2006

The influence of restorative treatment approaches and the use of local analgesia, on the children's discomfort.

AIM: The aim is to investigate possible differences in discomfort during treatment with the atraumatic restorative treatment (ART) or the Conventional restorative method with and without local analgesia (LA). METHODS: The study group consisted of 6 and 7 year old children with no dental experience (mean age 6.98, SD +/- 0.52) randomly divided into four treatment groups: Conventional method with and without LA and ART with and without LA. One or two proximal lesions in primary molars were treated. The heart rate and the behaviour (Venham) were measured. STATISTICS: Statistical analysis was performed in SPSS version 10.0. RESULTS: In a first session 300 children were treated and 109 children for a second time in the same way as at the first visit. During the first session ART without LA gave the least discomfort while the Conventional method without LA gave the most discomfort. During the second treatment the least discomfort was observed with ART without LA and the most discomfort in the Conventional way with LA. CONCLUSION: There is a constant preference for hand instruments; the bur is increasingly accepted. The experience with LA is the reverse.

Anesthesia, Dental↗
PubMed2006

Residual caries and marginal integrity in relation to Class II glass ionomer restorations in primary molars.

AIM: To assess the effectiveness of three treatment methods (ART, Carisolv(TM) and rotary instruments) in caries removal and sealing capability of hand-mixed glass ionomer in the management of proximal caries in deciduous molars. METHODS: In a clinical study 217 dentally naïve children (age 7.5, SD 0.57) were randomly divided in three treatment groups and among 4 operators. Each child received one class II glass ionomer restoration. Immediately after restoration bitewings were made. The dependent variables were: residual caries and marginal adaptation. Independent variables were operator effect, child's behaviour and time to remove caries. RESULTS: There was no statistical significant difference in residual caries between the three treatment methods (p < 0.05). In 33% of the cases a clear radiolucency underneath the restoration was visible on the bitewings. In 26% doubt existed on the presence of residual caries. A clear cervical gap was seen in 16% of the restorations, while in 18% signs of cervical gaps were less obvious. Between the four operators a significant difference in relation to residual caries (p = 0.015) was found as well as a significant difference between the operators for the preparation time in the three treatment methods (p < 0.05). The child's behaviour seems to have no influence on residual caries and marginal gaps. CONCLUSION: This study indicates that there is no preparation method superior to another, though the treatment methods seem to be sensitive for operator effects. Using hand-mixed glass ionomer cement resulted in considerable number of cervical gaps found.

Child↗
PubMed2006

Influence of residual caries and cervical gaps on the survival rate of Class II glass ionomer restorations.

AIM: To assess the influence of different variables on the survival of class II glass ionomer restorations a clinical study was carried out among 6-7 year old schoolchildren in and around Dar es Salaam, Tanzania. METHODS: 217 children were randomly divided into three groups. In the conventional group, Class-II cavities were excavated with burs, in the ART group they were excavated with hand instruments and in the Carisolv group excavation took place with a chemical solution and special blunt hand instruments. The preparations in all groups were restored with hand mixed glass ionomer cement (Fuji IX). Four operators were involved in the treatment phase. After restoration, residual caries and cervical gaps were assessed on bite-wings. The quality of the restorations was established and the survival rate determined in two subsequent evaluations. RESULTS: 195 children (90%) were present at the first evaluation which took place after 7 months and 194 (89%) were present at the second evaluation, after one year. At the first evaluation the survival rate of the ART-restorations was 38%, of the conventional restorations 50%, and of the Carisolv restorations 35%. Survival rates at the time of the second evaluation were 30%, 42% and 28% respectively. The differences between the three treatment groups were, however, not significant (p = 0.200 at t = 1 and p = 0.247 at t = 2). In the first evaluation 161 bitewings were available of the 195 restorations, while for the second evaluation 130 cases were available. There was no significant relation between residual caries and the success/failure rate (p = 0.140 at t = 1 and p = 0,201 at t = 2). Also cervical gaps appeared to have no relation with the failure rate (p = 0.057 at t = 1 and p = 0.833 at t = 2) However, together those variables have a significant influence on the survival rate (p = 0.025). CONCLUSION: The combination of two variables (residual caries and cervical gaps) has considerable influence on the survival rate of class II glass ionomer restorations compared to each variable alone.

Child↗
PubMed2006

[Needle breakage during mandibular block anaesthesia: prevention and retrieval].

Disposable needles for dental local anaesthesia do not break easily. Still, needle breakage does occur, and is mainly caused by unexpected movements of the patient or pre-use bending of the needle by the dentist. If a dental needle breaks while administering local anaesthesia, the dentist should prevent panic. If the patient opens his mouth wide the needle might still be visible. If so, the needle is removed. If the needle is no longer visible, the site where the needle has penetrated the mucosa should be marked with a permanent marker. The dentist will contact a maxillofacial surgeon for immediate consultation. The maxillofacial surgeon will try to retrieve the broken dental needle under general anaesthesia.

Dental Instruments↗
PubMed2004

[ART or conventional restorations? A final evaluation of proximal restorations in deciduous molars].

In this article the success rate of class 2 ART and conventional (prepared with a bur) restorations in deciduous molars is described. In 1999 approximately 200 ART and 200 conventional restorations were made in deciduous molars in Bandung, Indonesia. The restorations were evaluated after 1.5 month, half a year, 1 year, 2 years and 3 years. The three-year evaluation took place in October 2003. Results show that after 3 years 31% (ART) and 33.6% (conventional) of the restorations were successful (no significant difference). There was a significant difference between the operators. If keeping the element until shedding is the only criterion, the success rate increased to 53.

Child↗
PubMed2003

Atraumatic perspectives of ART: psychological and physiological aspects of treatment with and without rotary instruments.

Atraumatic Restorative Treatment, ART, is a method of minimal caries intervention that uses only hand instruments. The aim of the present study was to explore a possible difference between the extent of discomfort experienced during dental treatment according to the ART approach and a method using rotary instruments. The study was performed in Indonesia. A total of 403 children were randomly divided in two groups. In each child, one class II restoration in a deciduous molar was made. One group received treatment using rotary instruments (750 r.p.m.). The other group was treated according to the ART approach. Glass ionomer cement was used for restoration in both groups. Discomfort scores were determined using both physiological measurements (heart rate) and behavioral observations (Venham) on specific moments during the treatment. Venham scores showed a marked difference between the two groups at most time points. Heart rate measurements were different at deep excavation. Also, a clear relation between Venham scores and heart rate measurements could be found at all time points. Confounding could be shown for operating dentist, gender of the patient and initial anxiety, not for age. No effect modification could be shown. It can be concluded that children treated according to the ART approach using hand instruments alone experience less discomfort than those treated using rotary instruments.

Age Factors↗
PubMed1999

Cost-effectiveness of composite resins and amalgam in the replacement of amalgam Class II restorations.

OBJECTIVES: The replacement of an old amalgam Class II restoration is a common treatment and will remain so for decades. In addition to effectiveness, possible adverse health effects and esthetics, the costs of the treatment options will play a role in the choice of material. The aim of this study was to yield information on the relative cost-effectiveness of the use of composite resins and amalgam for the rerestoration of amalgam Class II restorations. METHODS: As part of a larger randomized clinical trial, treatment effectiveness and treatment costs were estimated in 73 composite and amalgam Class II posterior re-restorations. The main treatment outcome was longevity. Secondary outcomes included need of repair and quality of the margin while in situ. Costs were analyzed from the perspective of dentistry, assuming a treatment strategy aimed at offering 'value for money'. From this perspective, differential costs were based on personnel costs as approximated by treatment time. RESULTS: Replacing an amalgam Class II restoration with amalgam is associated with lower costs than replacing with a composite resin. A sensitivity analysis, considering type of composite, increasing proficiency with the material, and time needed for future removal of material, demonstrated that these differences are fairly robust. The materials performed equally well for the first 5 years after placement with respect to longevity. Differences in secondary outcomes were minor and not all in favor of the same material. CONCLUSIONS: It is tentatively concluded that amalgams are more cost-effective than composites for replacing existing Class II amalgam restorations.

Adolescent↗
PubMed1999

Is ART really atraumatic?

Atraumatic restorative treatment (ART) is an approach to the management of carious lesions that uses only hand instruments to remove carious tissue and to restore the tooth involved. The name ART implies that the approach is atraumatic to both the patient and the tooth. This study set out to evaluate whether ART is atraumatic in terms of both patient discomfort and tooth tissue conservation. Three hundred and fifty-nine patients were divided in two groups: one group was treated with hand instruments and the other with rotary equipment. Each patient received two restorations: one using amalgam and one using glass ionomer as the restorative material, placed without the use of anaesthesia. Less discomfort was reported with the ART approach compared to conventional restorations made using rotary instruments and amalgam. Moreover, preparations with hand instruments were smaller than those produced with rotary instruments. Reported discomfort was associated with the size of the preparation, although the influence of the operator on both criteria was considerable. A patient effect was also observed since patients who reported discomfort during the first treatment were more likely to report discomfort after the second treatment. In conclusion, the choice of the term "ART" as an atraumatic procedure is defensible.

Adolescent↗
PubMed1999

Bacterial counts in carious dentine under restorations: 2-year in vivo effects.

Little is known about the long-term effects of fluoride-releasing materials on carious dentine in vivo. The aim was to investigate the 2-year influence of a resin-modified glass ionomer cement (RM-GIC) and amalgam on the bacteriological counts of carious dentine that remained under class I restorations. To enable a split-mouth design, 33 molar pairs in 33 patients (mean age 15.1 years, SD 1.4) were selected, based on clinically and radiographically diagnosed occlusal dentine caries. The enamel of the carious molars was removed, and the carious dentine was sampled under aseptic conditions just beneath the dentinoenamel junction. The molars were alternately restored with RM-GIC or amalgam without further removal of carious dentine. The samples were processed for microbiological determination of total viable counts (TVC), mutans streptococci (MS), and lactobacilli (LB). The molar pairs of 25 patients were reevaluated after 2 years using the same clinical techniques and were permanently restored after complete caries removal. Both materials showed a substantial decrease in numbers of TVC and LB of the carious dentine after the 2-year period. Compared to amalgam, the decrease in the numbers of LB was significantly more pronounced for RM-GIC. No microorganisms were detected in only 11 molars (6 RM-GIC and 5 amalgam) after the 2-year period. Based on this study, we suggest that complete removal of carious dentine is still the best conservative treatment, irrespective of the restorative material used.

Adolescent↗
PubMed1998

Observer variation in the assessment of resin composite.

OBJECTIVES: The aim of this study was to compare the type of information obtained from log-linear modelling vs Cohen's kappa statistics on observer variation in the assessment of marginal adaptation in composite inlays and amalgam restorations. METHODS: Marginal adaptation of Class II resin composite inlays and amalgam restorations was clinically assessed by two observers, four years after placement. Each of 52 patients received 4 different restorations, three composite (Herculite XR, Clearfil CR Inlay and Visiomolar) inlays and one Tytin restoration. The results were evaluated by Cohens Kappa statistics and log-linear modelling. RESULTS: The overall Cohen's kappa was 0.45, ranging from poor to good for the four materials. Log-linear modelling confirmed that the observers agreed beyond chance but this agreement depended on the performance of the material. Marginal adaptation of Visiomolar (ESPE) inlays was somewhat inferior compared to the other materials. The assessment of Clearfil CR (Kuraray) inlay was difficult using this clinical evaluation procedure. SIGNIFICANCE: Using log-linear modelling it is possible to look at observer agreement and material performance at the same time. This combined approach is important because agreement may depend on material performance.

Chi-Square Distribution↗
PubMed1998

The analysis of restoration survival data in split-mouth designs.

OBJECTIVE: To report methodological difficulties with restoration survival data in controlled clinical trials on Class II amalgam restorations using a split-mouth design. The advantages and disadvantages of different ways of handling these data are described. METHODS: Three statistical methods (Kaplan-Meier estimation, logistic regression with random component and Friedman's statistic) are compared using data from a controlled clinical trial in which cavosurface angle (regular or non-standard) and cavity wall finish (applied or not applied) determine four treatment modalities of New True Dentalloy restorations. RESULTS: In this study logistic regression with a random component yields the best interpretable results. Cavity wall finish in combination with a regular cavosurface angle is indicated as the worst and cavity wall finish in combination with a non-standard cavosurface angle as the best treatment when the criterion is replacement or not within 15 years. CONCLUSIONS: The dependency between restorations within a patient needs to be taken into account. Logistic regression with a random component may be a valuable alternative to very advanced statistical survival modelling when restricting the research question to replacement within a certain time interval is not a major problem.

Dental Alloys↗
PubMed1998

Replacement risk of amalgam treatment modalities: 15-year results.

OBJECTIVES: This paper reports on the replacement risk of different treatment modalities for Class II amalgam restorations in a clinical trial of 15 years duration. METHODS: The performance of 1117 conventional Class II amalgam restorations in a controlled, longitudinal study were analysed using logistic regression with a random component. Primary variables regarding replacement risk were the treatment modality (cavity wall treatments) and alloy (conventional versus high copper). Secondly, the operator, type of tooth and type of restoration (MO/DO vs MOD) were considered. RESULTS: Over 15 years, 17% of the restorations were replaced (true failures). The application of copalite varnish or silver suspension and the type of alloy did not reduce the replacement risk. Reduced risks were observed by providing a 90-degree cavosurface angle combined with a cavity wall finish. The operator and the type of restoration determine replacement risk to a significant extent. CONCLUSIONS: Additional treatment modalities do not necessarily reduce replacement risks of Class II amalgam restorations within 15 years, while clinical variables affect the risk of replacement to a certain degree.

Adult↗
PubMed1997

In vivo cariostatic effect of resin modified glass ionomer cement and amalgam on dentine.

Fluoride-releasing materials have been reported to be bactericidal in vitro. This may be of benefit to modern dentistry, which is directed to the preservation of tooth tissue during restorative treatment. Little is known about in vivo effects. The aim is to investigate the influence of a resin-modified glass ionomer cement (RM-GIC) on carious dentine that remains under restorations, compared to amalgam. Using a split month design, 40 molar pairs in 40 patients (mean age 14.9 years) were selected, based on clinically and radiographically diagnosed occlusal dentine caries. Under aseptic conditions, the enamel was removed and the carious dentine was sampled just beneath the dentino-enamel junction using a round bur. Without further removal of carious dentine, the molars of a pair were alternately restored with RM-GIC or amalgam. The colour and the consistency of the carious dentine were assessed. The samples were processed for microbiological determination of total viable counts (TVC), mutans streptococci (MS), and lactobacilli (LB). After 6 months the molars were reopened, similarly sampled and evaluated, and then permanently restored after complete caries removal. For both materials a substantial decrease in the numbers of TVC, MS and LB was found after the 6-month period. Also a positive effect was observed on the colour and the consistency of the remaining carious dentine, which was comparable for the two materials. RM-GIC showed a significantly larger decrease in counts of MS and LB than amalgam, but not for TVC. Since in only few cavities the number of bacteria decreased under the level of detection, it is still considered essential to remove all carious dentine during restorative treatment.

Adolescent↗
PubMed1997

[Oral pathology in children. Part II. Abnormalities of the teeth].

An overview is presented of the various abnormalities of the teeth in children. Caries and periodontal diseases have not been discussed since each dentist is familiar with these diseases. Abnormalities of the teeth may occur as part of various syndromes. Occasionally, the dental findings lead to the detection of such underlying syndrome.

Child↗
PubMed1997

[Oral pathology in children. Part III. Abnormalities of the jaw bones].

Diseases of the jaw bones in children can be monostotic or polyostotic. Examples are fibrous dysplasia and Langerhans cell granulomatosis. Sarcomas of the jaw bones are rare, but do occur with some preference in children. The dentist should be aware of the clinical and even more so of the rather typical radiologic changes in such diseases.

Cherubism↗
PubMed1996

Dental caries under glass ionomer restorations.

The Atraumatic Restorative Treatment (ART) technique has two potential limitations. Because only hand instruments are used, dental caries can be left during cavity preparation. Beyond this limitation, the glass ionomer filling material currently used has some unfavorable mechanical properties with respect to its strength, wear resistance, and shrinkage during setting. The purpose of this paper is to provide an overview of changes that can be expected in carious dentin when a glass ionomer restoration is placed. Restriction of the substrate supply and the release of different components from the glass ionomer have an inhibiting effect on cariogenic microorganisms. Whether this influence is sufficient to completely arrest the caries process is doubtful. The influence of glass ionomers on the remineralization of carious dentin needs further research.

Bacteria↗