Microhardness of dentine underlying ART restorations in primary molars: an in vivo pilot study.
OBJECTIVE
To evaluate the microhardness of dentine underlying glass ionomer restorations made with Atraumatic Restorative Treatment.


METHODS
An experimental single-centre study.


METHODS
University Department, Brazil, 2001.


METHODS
Sixteen children were selected showing primary molars containing carious cavities (n = 29), which were restored using Fugi IX. Subsequently, some teeth were extracted respecting Nolla stage 7 or 8 of the permanent successor, and categorised according to the post-restoration time in the mouth: G1 (baseline, immediate extraction), G2 (30 days), G3 (90 days) and G4 (180 days). Four teeth were excluded because they were not in time of normal exfoliation. The 25 extracted teeth were resin embedded, sectioned mesiodistally and prepared metallographically. Knoop microhardness analysis (Micromet 2003; 10g for 1.5 sec.) produced identations in three areas of dentine: Zone 1 (just below the restoration), Zone 3 (as close as possible to the pulp) and Zone 2 (intermediate region between 1 and 3). Non-parametric statistical tests were done--at a significance level of 5%.


RESULTS
Four teeth were excluded. No significant difference was noted among the zones, inside the groups. Zones 1 and 2 showed a considerable increase of microhardness according to the time, except for Group 3 (p > 0.05).


CONCLUSIONS
Although microhardness had increased, it was not sufficiently equal to the microhardness of the healthy dentine, regardless of the depth evaluated.
Santiago
B M
BM
Department of Pediatric Dentistry and Orthodontics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. biasantiago@openlink.com.br
Ventin
D A
DA
Primo
L G
LG
Barcelos
R
R
D002648:Child; D003731:Dental Caries / Q000473:pathology / Q000628:therapy; D003737:Dental Cavity Preparation / Q000379:methods*; D003793:Dental Restoration, Permanent / Q000379:methods*; D003804:Dentin / Q000187:drug effects*; D005899:Glass Ionomer Cements / Q000494:pharmacology*; D006244:Hardness / Q000187:drug effects; D006801:Humans; D008963:Molar / Q000187:drug effects; D010865:Pilot Projects; D018709:Statistics, Nonparametric; D014080:Tooth Exfoliation; D014081:Tooth Extraction; D014094:Tooth, Deciduous / Q000187:drug effects
D005899:Glass Ionomer Cements; C110713:fuji IX