Contiguous teeth extraction caused significantly more alveolar ridge bone loss as compared with when a single tooth is extracted.

The enamel matrix derivative (EMD) is a preparation of the enamel matrix proteins secreted by the Hertwig's epithelial root sheath. It has been shown that EMD promotes periodontal wound healing; however, the significance of the protein in repairing skin wounds is insufficiently addressed. The aim of this in vivo histomorphometric investigation was to analyse the effect of EMD protein on the healing of standardised epithelial wounds. Dorsal skin of 22-week-old female guinea pigs (n = 33) was scarified and divided into test- (topical application of EMD) and control-sites (sutured and allowed to heal). Animals were euthanised at specific time intervals and the specimens were then evaluated histomorphometrically. The mean widths of the external wound gaps (WGs) in the test- and control-sites at the 5th, 20th and 35th day of healing were 5·89, 3·6 and 1·01 mm and 6·41, 5·02 and 3·43 mm, respectively. Histomorphometric analysis showed a statistically significant difference in the WGs between the test- and control-sites. A significant increase in the formation of organised connective tissue matrix, collagen fibres and early muscle formation was observed in the test-sites as compared with the control-sites. Within the limits of this study, it is concluded that topical application of the EMD on standardised epithelial allows early wound closure and promotes healing as compared to when the defects are merely sutured.

The enamel matrix derivative (EMD) has been used extensively as an adjunct to root coverage procedures to achieve periodontal regeneration. However, its effect on gingival tissues has not been elucidated. The aim of this investigation was to evaluate histometrically the change in gingival soft tissue thickness around dehiscence-type defects treated with EMD. Five adult female beagle dogs were used. Buccal osseous dehiscences were surgically created on the maxillary canines and the second and fourth premolars. Thirty defect sites were randomly assigned to test and control groups (15 defect sites for each group). The test group received EMD application, whereas the control group did not. After 4 months of healing, the dogs were killed and tissue blocks were prepared. Histometric analysis showed that the mean thickness of gingival tissue was 1.76 ± 0.23 mm in EMD-treated sites compared to 0.72 ± 0.11 mm for control sites. The difference between the test and control groups was statistically significant (P < 0.0001). It appears that EMD has a positive influence on the increase in gingival tissue thickness when used in dehiscence-type defects in the beagle dog.