[PPS-O-2] Histological observation on periodontal tissue after vertical root fracture repair with 4-META/MMA-TBB resin
[Abstract]
[Objective]
Periodontal pocket will remain after vertical root fracture (VRF) repair and could be problematic. To solve this problem, the purpose of this study was to investigate tissue responses to VRF repair with 4-META/MMA-TBB resin (Superbond, Sun Medical, Japan; SB), SB mixed with nano-hydroxyapatite (naHAp/SB), and enamel matrix derivative (Emdogain, Straumann, USA) (Em/naHAp/SB).
[Method]
Thirty 4-week-old Sprague-Dawley rats were used. After general anesthesia, both maxillary first molars were extracted. VRF imitating groove was created at the mesial surface of the mesial root from the cementoenamel junction to the root apex using a diamond disc and pulpal tissue was removed. For SB and naHAp/SB group, materials were mixed and applied to the cavity. For Em/naHAp/SB group, Emdogain was mixed with the naHAp/SB. In the control group, the groove was not repaired. Tooth was soaked in saline solution for 10 min before replanting and stabilized with adjacent tooth. Opposing tooth was extracted. Three rats from each experimental group and one rat from the control were euthanized after 2, 4, and 6 weeks. Samples were stained with Hematoxylin and Eosin and Masson Trichrome histologically investigated, and analyzed with descriptive statistics.
[Results and Discussion]
No ankylosis, inflammation, or root resorption was observed in naHAp/SB and Em/naHAp/SB groups. Newly formed bone and cementum-like tissue were found in periodontal ligament but fibrous tissue was aligned parallel to the root surface. Connective tissue layer became narrower when the time passed. In SB group, mild-moderate inflammation was observed while severe inflammation was observed in the control group. No hard tissue formation was found in the latter two groups. Even naHAp/SB was shown to induce hard tissue formation in case of pulp-capping [1], The challenge of this study was that the ratio of cavity/tooth size was considerably bigger than that of clinical repair.
[Conclusion]
The possibility of regenerating the hard tissue at the surface of repair materials upon VRF repair was suggested. Longer observation period is required to confirm the findings.
[References]
Yoshida S, et. al. Development of a novel direct dental pulp-capping material using 4-META/MMA-TBB resin with nano-hydroxyapatite. Mater Sci Eng C Mater Biol Appl. 2021; 130
[Objective]
Periodontal pocket will remain after vertical root fracture (VRF) repair and could be problematic. To solve this problem, the purpose of this study was to investigate tissue responses to VRF repair with 4-META/MMA-TBB resin (Superbond, Sun Medical, Japan; SB), SB mixed with nano-hydroxyapatite (naHAp/SB), and enamel matrix derivative (Emdogain, Straumann, USA) (Em/naHAp/SB).
[Method]
Thirty 4-week-old Sprague-Dawley rats were used. After general anesthesia, both maxillary first molars were extracted. VRF imitating groove was created at the mesial surface of the mesial root from the cementoenamel junction to the root apex using a diamond disc and pulpal tissue was removed. For SB and naHAp/SB group, materials were mixed and applied to the cavity. For Em/naHAp/SB group, Emdogain was mixed with the naHAp/SB. In the control group, the groove was not repaired. Tooth was soaked in saline solution for 10 min before replanting and stabilized with adjacent tooth. Opposing tooth was extracted. Three rats from each experimental group and one rat from the control were euthanized after 2, 4, and 6 weeks. Samples were stained with Hematoxylin and Eosin and Masson Trichrome histologically investigated, and analyzed with descriptive statistics.
[Results and Discussion]
No ankylosis, inflammation, or root resorption was observed in naHAp/SB and Em/naHAp/SB groups. Newly formed bone and cementum-like tissue were found in periodontal ligament but fibrous tissue was aligned parallel to the root surface. Connective tissue layer became narrower when the time passed. In SB group, mild-moderate inflammation was observed while severe inflammation was observed in the control group. No hard tissue formation was found in the latter two groups. Even naHAp/SB was shown to induce hard tissue formation in case of pulp-capping [1], The challenge of this study was that the ratio of cavity/tooth size was considerably bigger than that of clinical repair.
[Conclusion]
The possibility of regenerating the hard tissue at the surface of repair materials upon VRF repair was suggested. Longer observation period is required to confirm the findings.
[References]
Yoshida S, et. al. Development of a novel direct dental pulp-capping material using 4-META/MMA-TBB resin with nano-hydroxyapatite. Mater Sci Eng C Mater Biol Appl. 2021; 130