Periodontal regenerative techniques have been proposed; however, the outcomes remain debatable. The present investigation assessed the regenerated cementum following enamel matrix derivative application in dehiscence-type defects. Buccal osseous dehiscences were surgically created on the maxillary cuspid, and the second and fourth premolars in five female beagle dogs. The treatment group (n = 15 sites) received the enamel matrix derived application, whereas the control groups (n = 15) did not. The dogs were sacrificed 4 months following treatment and the specimens were histologically and histometrically examined. The newly formed cementum was uneven in thickness and mineralization, overlapped the old cementum and exhibited functional orientation, cementocyte lacunae and collagen fibril bundles. Most of the histological specimens showed the presence of a gap between the newly formed cementum and the underlying dentin. Control sites did not exhibit any cementum formation. The present study concluded that newly formed cementum is of cellular type and exhibits multiple characteristics.
Animals ; Cementogenesis ; drug effects ; Dental Cementum ; cytology ; drug effects ; surgery ; Dental Enamel Proteins ; pharmacology ; Dogs ; Female ; Random Allocation ; Regeneration ; drug effects ; Surgical Wound Dehiscence

The present investigation assessed the effect of acid etching on marginal adaptation of white- and gray-colored mineral trioxide aggregate (MTA) to apical dentin using microcomputed tomography (micro-CT) and scanning electron microscopy (SEM). Sixty-four extracted single-rooted human maxillary teeth were used. Following root-end resection and apical preparation, the teeth were equally divided into four groups according to the following root end filling materials: (i) white-colored MTA (WMTA), (ii) etched WMTA (EWMTA), (iii) gray-colored MTA (GMTA) and (iv) etched GMTA (EGMTA). After 48 h, the interface between root-end filling materials and the dentinal walls was assessed using micro-CT and SEM. Data were statistically analyzed using the Kruskal-Wallis and Dunn tests. Micro-CT analysis revealed gap volumes between the apical cavity dentin walls and EGMTA, GMTA, EWMTA and WMTA of (0.007 1±0.004) mm(3), (0.053±0.002) mm(3), (0.003 6±0.001) mm(3) and (0.005 9±0.002) mm(3) respectively. SEM analysis revealed gap sizes for EGMTA, WMTA, EWMTA and GMTA to be (492.3±13.8) µm, (594.5±17.12) µm, (543.1±15.33) µm and (910.7±26.2) µm respectively. A significant difference in gap size between root end preparations filled with GMTA and EGMTA was found (P<0.05). No significance difference in gap size between WMTA and EWMTA were found in either SEM or micro-CT analysis. In conclusion, pre-etching of apical dentin can provide a better seal for GMTA but not for WMTA.
Acid Etching, Dental ; methods ; Aluminum Compounds ; chemistry ; Apicoectomy ; methods ; Calcium Compounds ; chemistry ; Dental Bonding ; Dental Marginal Adaptation ; Dental Pulp Cavity ; ultrastructure ; Dentin ; ultrastructure ; Drug Combinations ; Humans ; Materials Testing ; Microscopy, Electron, Scanning ; Oxides ; chemistry ; Retrograde Obturation ; methods ; Root Canal Filling Materials ; chemistry ; Root Canal Preparation ; instrumentation ; methods ; Silicates ; chemistry ; Surface Properties ; Time Factors ; Tooth Apex ; ultrastructure ; X-Ray Microtomography