Periodontal tissue response to coverage of root cavities restored with resin materials: a histomorphometric study in dogs.
BACKGROUND
The purpose of this study was to histomorphometrically evaluate the response of periodontal tissues covering Class V resin restorations in dogs.


METHODS
After raising a mucoperiosteal flap, bony defects measuring 5 x 5 mm were created on the buccal aspect of the canines of five dogs followed by cavity preparations on the root surface measuring 3 x 3 x 1 mm. Before repositioning the flap to cover the bone defect, the cavities were restored with composite resin (CR) or resin-modified glass ionomer cement (RMGIC) or were left unrestored as control (C). The dogs were euthanized 90 days after surgery. Specimens comprising the tooth and periodontal tissues were removed, processed routinely, cut into longitudinal serial sections in the buccolingual direction, and stained with hematoxylin and eosin (H&E) or Masson's trichrome. The most central sections were selected for histomorphometric analysis.


RESULTS
Histomorphometric analysis revealed apical migration of epithelial tissue onto the restorative materials (RMGIC and CR). The C group presented significantly longer connective tissue attachment (P <0.05) than the RMGIC and CR groups and significantly higher bone regeneration (P <0.05) compared to the RMGIC group. Histologically, the cervical third (CT) of all groups had the most marked chronic inflammatory infiltrate.


CONCLUSIONS
Within the limits of this study, it can be concluded that the restorative materials used exhibit biocompatibility; however, both materials interfered with the development of new bone and the connective tissue attachment process.
Martins
Thiago M
TM
Department of Surgery and Integrated Clinic, Dental School of Araçatuba, São Paulo State University Júlio de Mesquita Filho, Araçatuba, SP, Brazil.
Bosco
Alvaro F
AF
Nóbrega
Fernando J O
FJ
Nagata
Maria J H
MJ
Garcia
Valdir G
VG
Fucini
Stephen E
SE
D000180:Acrylic Resins / Q000009:adverse effects / Q000627:therapeutic use*; D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects / Q000627:therapeutic use*; D003188:Composite Resins / Q000009:adverse effects / Q000627:therapeutic use*; D003731:Dental Caries / Q000628:therapy; D004285:Dogs; D005899:Glass Ionomer Cements / Q000009:adverse effects / Q000627:therapeutic use*; D017622:Periodontal Attachment Loss / Q000139:chemically induced; D010510:Periodontal Diseases / Q000139:chemically induced / Q000628:therapy*; D011140:Polyurethanes / Q000009:adverse effects / Q000627:therapeutic use*; D013524:Surgical Flaps; D014092:Tooth Root; D014945:Wound Healing / Q000502:physiology
D000180:Acrylic Resins; D001672:Biocompatible Materials; C029012:Composite Dental Resin; D003188:Composite Resins; D005899:Glass Ionomer Cements; D011140:Polyurethanes