Regenerative potential and healing dynamics of the periodontium: a critical‐size supra‐alveolar periodontal defect study

Abstract

The nature and characteristics of the newly formed periodontium obtained following regenerative procedures remain a matter of controversy. The objective of this study was to evaluate the regenerative potential of the periodontal attachment and healing dynamics as observed from the spatial distribution of newly formed cementum, periodontal ligament (PDL) and alveolar bone following optimal circumstances for wound healing/regeneration in a discriminating animal model. Critical-size, 6-mm, supra-alveolar, periodontal defects were surgically created in six young adult Beagle dogs. Space-providing ePTFE devices with 300-microm laser-drilled pores were implanted to support wound stability and space provision in one jaw quadrant/animal. Treatments were alternated between left and right jaw quadrants in subsequent animals. The gingival flaps were advanced to submerge the defect sites for primary intention healing. Histometric analysis followed an 8-week healing interval. Healing was uneventful in all animals. The histometric analysis showed that cementum regeneration (2.99 +/- 0.22 mm) was significantly greater than PDL (2.54 +/- 0.18 mm, p=0.03) and bone regeneration (2.46 +/- 0.26 mm, p=0.03). The wound area showed significant positive non-linear effect on cementum (log beta=1.25, p<0.001), PDL (log beta=1.24, p<0.001) and new bone formation (log beta=1.36, p<0.001). A high degree of concordance and significant linear relationship was observed between cementum, PDL and bone regeneration indicating that their formation virtually occurred in parallel. Cementum, PDL and alveolar bone virtually regenerate in parallel under optimal circumstances for periodontal wound healing/regeneration. Moreover, space provision positively influences the extent of periodontal regeneration.