Histologic tissue response to furcation perforation repair using mineral trioxide aggregate or dental pulp stem cells loaded onto treated dentin matrix or tricalcium phosphate

H Bakhtiar,M Baghaban Eslaminejad,D Sharifi,F Mashhadiabbas,M R Bagheri,H Mirzaei,Pmh Dummer,N Fani,M H Nekoofar

doi:10.1007/s00784-016-1967-0

Abstract

ObjectivesThe aim of this study is to compare the effect of treated dentine matrix (TDM) and tricalcium phosphate (TCP) scaffolds on odontogenic differentiation and mineralization of dental pulp stem cells (DPSCs) in furcation perforations created in the pulp chamber floor of premolar teeth in dogs.Material and methodsDPSCs were isolated and cultured from the dental pulp of the maxillary left second and third premolars of dogs. The DPSCs were loaded on TCP (SC+TCP) and TDM (SC+TDM) scaffolds and inserted into intentionally perforated pulp chamber floors of premolars in dogs; six teeth were used for each group. Three more groups of six specimens were created, and mineral trioxide aggregate (MTA), TDM, and TCP were inserted into the perforations to act as controls. An intact premolar and no treatment in the perforation site were used as positive and negative controls respectively. After 3 months, the animals were sacrificed and the type of inflammation, presence of dentine, continuation and type of cementum, type of connective tissue, and presence of foreign body reaction were evaluated, and significant differences were between groups determined using the Fisher’s exact test. The evaluation of the amount of inflammation and the percentage of new bone formation was evaluated using the Mann-Whitney U test.ResultsThe negative control group was associated with severe inflammation and granulation tissue formation. In the positive control group, intact periodontal tissues and no inflammation were observed. Dentine bridge formation was not seen in specimens of any group. The specimens in the SC+TDM group were associated with significantly more bone formation than other groups (P < 0.001). The amount of inflammation was less than 10 % in specimens of all groups with the exception of three specimens in the TCP group that were categorized as 10–30 %. Chronic inflammation without foreign body reactions was the major pattern of inflammation in groups. Formation of cementum with a cellular and continuous appearance was seen in all specimens.ConclusionsSC+TDM was associated with significantly more bone formation when used to repair uninfected furcation perforations in the premolar teeth of dogs.Clinical relevanceApplication of TDM as a biological scaffold in combination with DPSCs may offer an advantage during the repair of root perforation defects.

Highlights

Materials and methodsFurcal perforations are the consequence of procedural errors or pathologic processes, such as caries or root resorption, and can affect the outcome of root canal treatment
SC+treated dentine matrix (TDM) was associated with significantly more bone formation when used to repair uninfected furcation perforations in the premolar teeth of dogs
Clinical relevance Application of TDM as a biological scaffold in combination with dental pulp stem cells (DPSCs) may offer an advantage during the repair of root perforation defects

Summary

Results

Seven to 10 days after the initiation of the primary culture, several large colonies of fibroblastic cells were detected which increased in size and became confluent. The difference between the TDM and DPSC+TDM groups was significant (P < 0.001), which indicates that the presence of DPSCs effectively increased the ability of the material to regenerate tissue This result ruled out our null hypothesis of equal impact of TDM and TCP on differentiation of DPSCs. The two-rooted dog premolars, which were used in this study, have bifurcations close to the CEJ (1–2 mm). Tada et al [29] suggested that the chemical composition of TCP with high concentration of calcium and phosphate could increase bone morphogenic protein-2 (BMP-2) expression through cyclic adenosine monophosphate–dependent protein kinase and extracellular signal-regulated kinase 1/2 pathways in human DPSCs. The histological findings of the present study revealed that the highest and the lowest mean values of new bone formation were associated significantly with specimens of DPSCs seeded on TDM (stem cell + TDM) and pure TCP specimens, respectively (P < 0.001). Considering more than 100 published papers, there is a huge attempt to produce techniques for processing of bone graft material using extracted teeth and it could be anticipated developing scaffolds from homogenous and xenogenous tooth and dental restorative materials using extracted teeth in the near future [38]

Materials and methods

Compliance with ethical standards