Metal and ceramic bracket effects on human buccal mucosa epithelial cells.
OBJECTIVE
To test the null hypothesis that metal and ceramic brackets have no effect on the epithelial cells of the buccal mucosa.


METHODS
Two metal and two ceramic brackets were bonded in 21 individuals of both sexes. With the use of liquid-based exfoliative cytology, morphometric and morphologic changes in buccal mucosa cells adjacent to these brackets were determined and were compared at three time points: baseline (T0), 60 days after placement (T1), and 30 days after removal of the brackets (T2).


RESULTS
A decrease in nuclear area and an increase in cytoplasmic area occurred in the buccal mucosa cells adjacent to the brackets at T1 (P < .01). At T2, this altered morphometry persisted only in cells adjacent to the metal brackets, although to a lesser degree than at T1 (P < .01). A greater decrease in nuclear area was noted in cells adjacent to the metal brackets than in those next to the ceramic brackets (P < .01). At T0, the proportions of surface and subsurface cells were similar, but at T1, a predominance of surface cells was observed (P < .05). At all time points, smears of cells appeared normal or normal with some inflammatory changes.


CONCLUSIONS
The hypothesis is rejected. Placement of metal and ceramic brackets in the buccal cavity induces cellular alterations. These alterations do not suggest malignancy.
Pereira
Betina R
BR
Pontifical Catholic University of Parana, Curitiba, Brazil.
Tanaka
Orlando M
OM
Lima
Antônio A S
AA
Guariza-Filho
Odilon
O
Maruo
Hiroshi
H
Camargo
Elisa S
ES
D000293:Adolescent; D000328:Adult; D001641:Bicuspid; D002467:Cell Nucleus / Q000473:pathology; D048430:Cell Shape; D002516:Ceramics / Q000737:chemistry*; D002648:Child; D004396:Coloring Agents; D003581:Cytodiagnosis; D003593:Cytoplasm / Q000473:pathology; D003722:Dental Alloys / Q000737:chemistry*; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008422:Materials Testing; D008437:Maxilla; D008875:Middle Aged; D008963:Molar; D009061:Mouth Mucosa / Q000473:pathology*; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry; D013280:Stomatitis / Q000473:pathology; D014094:Tooth, Deciduous; D055815:Young Adult
D004396:Coloring Agents; D003722:Dental Alloys; D003764:Dental Materials; D019279:Resin Cements; C477790:Transbond XT