講演情報
[P-78（E）]Histological investigation on periodontal tissue after vertical root fracture repair with 4-META/MMA-TBB resin mixed with nano-hydroxyapatite and enamel matrix derivative
*Chuta Kooanantkul1,2, Masako Nagasawa1, Hikaru Koide1, Katsumi Uoshima1 (1. Department of Bio-Prosthodontics, Niigata University, 2. Department of Operative Dentistry and Endodontics, Mahidol University)
[Objective]
Periodontal pocket remaining after the repair of the vertical root fracture (VRF) could be problematic. 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]
Fifty-four 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 an interproximal strip 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. Non-repaired groove was used as a control. The tooth was soaked in a saline solution mixed with 2% tetracycline and 2% stannous fluoride for 10 min before replanting and stabilizing with the adjacent tooth. 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, Masson Trichrome, and anti-periostin, anti-osterix, anti-osteocalcin antibodies.
[Results and Discussion]
No ankylosis, inflammation, or root resorption was observed in the naHAp/SB and Em/naHAp/SB groups. Newly formed hard tissue was found close to the materials. Periodontal fiber was aligned parallel to the root surface. Mild-moderate inflammation and root resorption were found in the control and SB groups and no hard tissue was formed. Higher anti-periostin, anti-osterix, and anti-osteocalcin positive areas were observed in all experimental groups compared with the control group. Even naHAp/SB was shown to induce hard tissue formation in the case of pulp-capping 1), there was no such reaction. The challenge of this study was that the ratio of cavity/tooth size was considerably higher than human cases.
[Conclusion]
The possibility of regenerating the hard tissue at the surface of repair materials upon VRF repair was suggested. A longer observation period is required.
[Reference]
1) Yoshida S, Sugii H, Itoyama T 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;130:112426.
Periodontal pocket remaining after the repair of the vertical root fracture (VRF) could be problematic. 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]
Fifty-four 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 an interproximal strip 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. Non-repaired groove was used as a control. The tooth was soaked in a saline solution mixed with 2% tetracycline and 2% stannous fluoride for 10 min before replanting and stabilizing with the adjacent tooth. 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, Masson Trichrome, and anti-periostin, anti-osterix, anti-osteocalcin antibodies.
[Results and Discussion]
No ankylosis, inflammation, or root resorption was observed in the naHAp/SB and Em/naHAp/SB groups. Newly formed hard tissue was found close to the materials. Periodontal fiber was aligned parallel to the root surface. Mild-moderate inflammation and root resorption were found in the control and SB groups and no hard tissue was formed. Higher anti-periostin, anti-osterix, and anti-osteocalcin positive areas were observed in all experimental groups compared with the control group. Even naHAp/SB was shown to induce hard tissue formation in the case of pulp-capping 1), there was no such reaction. The challenge of this study was that the ratio of cavity/tooth size was considerably higher than human cases.
[Conclusion]
The possibility of regenerating the hard tissue at the surface of repair materials upon VRF repair was suggested. A longer observation period is required.
[Reference]
1) Yoshida S, Sugii H, Itoyama T 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;130:112426.