Construction of an experimental miller Ⅲ gingival retraction animal model in beagle dogs

To construct a Miller class Ⅲ gingival recession animal model and to lay the foundation for exploring the treatment of Miller class Ⅲ gingival recession.

Two adult male beagle dogs were selected, and four teeth from each beagle dog were selected to establish an experimental Miller class Ⅲ gingival recession model. The root surface was revealed by removing the soft and hard tissues of the buccal side. The success of the model was determined by measuring the vertical gingival retraction (VGR), horizontal retraction (HGR), keratosis tissue width (KTW), gingival tissue thickness (GTT), and probing depth (PD) at 1, 2, 4, 6, and 8 weeks after modeling.

After observing the clinical indexes, the PDs before and after the modeling were all smaller than 3 mm and no deep-period pockets were formed. The VGR before modeling was 0 mm, and the VGR range after modeling was 5-6.38 mm. A comparison of the before and after modeling results showed that this difference was statistically significant (P < 0.05). The postoperative VGR results were grouped according to timepoint. A comparison between the two groups showed that the differences at 2, 4, 6 and 8 weeks postoperatively were not statistically significant (P > 0.05). The HGR before the modeling was 0 mm, and the HGR fluctuated around 10.5 mm after the modeling, and this difference was statistically significant (P < 0.05). The HGR results were grouped by timepoint after surgery, and a one-way analysis of showed that the differences between the two groups were not statistically significant (P > 0.05). The KTW range before modeling was 6~9 mm, and it fluctuated around 2 mm after modeling, and this difference was statistically significant (P < 0.05). The KTW results were grouped by timepoint after surgery, and they indicated that significant differences did not occur between the groups postoperatively (P > 0.05). The pre-modeling GTT was 1.5 mm, and the GTT range after modeling was 1.5-2 mm. The preoperative and postoperative GTT results were grouped by timepoint, and the results showed that significant differences did not occur between 1 week and 2 weeks after surgery (P = 0.123), although a statistically significant difference was observed at 1 week postoperatively between this group and the other groups (P < 0.05).

The method used in this experiment can successfully build a Miller class Ⅲ gingival recession animal model, and the model remains stable after wound healing.