Responses of canine periodontal ligament cells to bubaline blood derived platelet rich fibrin in vitro.

Platelet-rich fibrin (PRF) promotes wound healing by providing the release of growth factors. Here, the influence of Thai and Murrah bubaline blood derived PRF on canine periodontal ligament cells (cPDLs) was investigated. PRF was prepared from Thai and Murrah buffaloes with single centrifugation. Results demonstrated that Thai bubaline blood derived PRF exhibited fiber-mesh like morphology and contained more platelet entrapment than Murrah bubaline blood derived PRF. Both bubaline PRFs were able to degrade in vitro under condition with trypsin. Thai but not Murrah bubaline blood derived PRF promoted cPDLs proliferation in serum free and 2% serum culture conditions. Correspondingly, the significant upregulation of KI67 mRNA expression was observed in those cells treated with Thai bubaline blood derived PRF. However, both Thai and Murrah bubaline blood derived PRF accelerated cell migration in an in vitro wound healing assay and facilitated cell spreading. Further, cPDLs cultured in osteogenic induction medium supplemented with Thai bubaline blood derived PRF exhibited the increased mineral deposition in vitro. Frozen Thai bubaline blood derived PRF also promoted cell proliferation, KI67 mRNA expression, cell migration, and cell spreading in cPDLs. Taken these evidence together, bubaline blood derived PRF could provide potential benefits for canine periodontal tissue healing.

Human dental pulp stem cell responses to different dental pulp capping materials.

BACKGROUND: Direct pulp capping is a vital pulp therapy for a pin-point dental pulp exposure. Applying a pulp capping material leads to the formation of a dentin bridge and protects pulp vitality. The aim of this study was to compare the effects of four dental materials, DyCal®, ProRoot® MTA, Biodentine™, and TheraCal™ LC in vitro. METHODS: Human dental pulp stem cells (hDPs) were isolated and characterized. Extraction medium was prepared from the different pulp capping materials. The hDP cytotoxicity, proliferation, and migration were examined. The odonto/osteogenic differentiation was determined by alkaline phosphatase, Von Kossa, and alizarin red s staining. Osteogenic marker gene expression was evaluated using real-time polymerase chain reaction. RESULTS: ProRoot® MTA and Biodentine™ generated less cytotoxicity than DyCal® and TheraCal™ LC, which were highly toxic. The hDPs proliferated when cultured with the ProRoot® MTA and Biodentine™ extraction media. The ProRoot® MTA and Biodentine™ extraction medium induced greater cell attachment and spreading. Moreover, the hDPs cultured in the ProRoot® MTA or Biodentine™ extraction medium migrated in a similar manner to those in serum-free medium, while a marked reduction in cell migration was observed in the cells cultured in DyCal® and TheraCal™ LC extraction media. Improved mineralization was detected in hDPs maintained in ProRoot® MTA or Biodentine™ extraction medium compared with those in serum-free medium. CONCLUSION: This study demonstrates the favorable in vitro biocompatibility and bioactive properties of ProRoot® MTA and Biodentine™ on hDPs, suggesting their superior regenerative potential compared with DyCal® and TheraCal™.

Characterization of a bioactive Jagged1-coated polycaprolactone-based membrane for guided tissue regeneration.

OBJECTIVE: The aim of the present study was to develop a Jagged1-coated polycaprolactone (PCL) membrane and to evaluate the response of human periodontal ligament cells (hPDL) on this membrane in vitro. METHODS: Membranes were prepared from PCL and PCL-incorporated hydroxyapatite (PCL/HA). The membranes' surface roughness, surface wettability, and mechanical properties were examined. An indirect affinity immobilization technique was used to coat the membranes with Jagged1. Membrane cytotoxicity was evaluated using LIVE/DEAD and MTT assays. The morphology of the cells on the membranes was observed using scanning electron microscopy. hPDL alkaline phosphatase (ALP) enzymatic activity and mineral deposition were examined using an ALP assay and Alizarin Red S staining, respectively. Notch target gene mRNA expression was determined using real-time polymerase chain reaction. RESULTS: The PCL/HA membranes exhibited a significantly reduced surface contact angle, decreased maximum tensile strain, and ultimate tensile stress. However, the surface roughness parameters were significantly increased. The PCL and PCL/HA membranes were not cytotoxic to hPDL in vitro. hPDLs attached and spread on both membrane types. Further, indirect affinity immobilized Jagged1 on the membranes upregulated hPDL Notch target gene expression. After culturing in osteogenic medium, Jagged1-immobilized PCL/HA membranes significantly enhanced hPDL ALP enzymatic activity. CONCLUSION: Indirect immobilized Jagged1 PCL/HA membranes could be further developed as an alternative guided tissue regeneration membrane to promote osteogenic differentiation in periodontal defects.

A Profilometry-Based Dentifrice Abrasion Method for V8 Brushing Machines Part III: Multi-Laboratory Validation Testing of RDA-PE.

OBJECTIVES: We have previously reported on progress toward the refinement of profilometry-based abrasivity testing of dentifrices using a V8 brushing machine and tactile or optical measurement of dentin wear. The general application of this technique may be advanced by demonstration of successful inter-laboratory confirmation of the method. The objective of this study was to explore the capability of different laboratories in the assessment of dentifrice abrasivity using a profilometry-based evaluation technique developed in our Mason laboratories. In addition, we wanted to assess the interchangeability of human and bovine specimens. METHODS: Participating laboratories were instructed in methods associated with Radioactive Dentin Abrasivity-Profilometry Equivalent (RDA-PE) evaluation, including site visits to discuss critical elements of specimen preparation, masking, profilometry scanning, and procedures. Laboratories were likewise instructed on the requirement for demonstration of proportional linearity as a key condition for validation of the technique. Laboratories were provided with four test dentifrices, blinded for testing, with a broad range of abrasivity. In each laboratory, a calibration curve was developed for varying V8 brushing strokes (0, 4,000, and 10,000 strokes) with the ISO abrasive standard. Proportional linearity was determined as the ratio of standard abrasion mean depths created with 4,000 and 10,000 strokes (2.5 fold differences). Criteria for successful calibration within the method (established in our Mason laboratory) was set at proportional linearity = 2.5 ± 0.3. RDA-PE was compared to Radiotracer RDA for the four test dentifrices, with the latter obtained by averages from three independent Radiotracer RDA sites. Individual laboratories and their results were compared by 1) proportional linearity and 2) acquired RDA-PE values for test pastes. RESULTS: Five sites participated in the study. One site did not pass proportional linearity objectives. Data for this site are not reported at the request of the researchers. Three of the remaining four sites reported herein tested human dentin and all three met proportional linearity objectives for human dentin. Three of four sites participated in testing bovine dentin and all three met the proportional linearity objectives for bovine dentin. RDA-PE values for test dentifrices were similar between sites. All four sites that met proportional linearity requirement successfully identified the dentifrice formulated above the industry standard 250 RDA (as RDA-PE). The profilometry method showed at least as good reproducibility and differentiation as Radiotracer assessments. It was demonstrated that human and bovine specimens could be used interchangeably. CONCLUSIONS: The standardized RDA-PE method was reproduced in multiple laboratories in this inter-laboratory study. Evidence supports that this method is a suitable technique for ISO method 11609 Annex B.