Teriparatide (recombinant parathyroid hormone 1-34) enhances bone allograft integration in a clinically relevant pig model of segmental mandibulectomy

Medications Affecting Treatment Outcomes in Dentistry: Part 2

Today, it is common for medically complex patients who are receiving multiple medications, to seek routine and emergent dental care. It is essential for the practitioner to recognize and comprehend the impact of such medications on the patient's ability to tolerate the planned dental treatment and on dental treatment outcomes. An active appraisal of current literature is essential to stay abreast of emerging findings and understand their treatment implications. This article outlines the process of such active critical appraisal, illustrating key paradigms of the models that describe the impact of medications on treatment outcomes.

A parathyroid hormone related supramolecular peptide for multi-functionalized osteoregeneration

Supramolecular peptide nanofiber hydrogels are emerging biomaterials for tissue engineering, but it is difficult to fabricate multi-functional systems by simply mixing several short-motif-modified supramolecular peptides because relatively abundant motifs generally hinder nanofiber cross-linking or the formation of long nanofiber. Coupling bioactive factors to the assembling backbone is an ideal strategy to design multi-functional supramolecular peptides in spite of challenging synthesis and purification. Herein, a multi-functional supramolecular peptide, P1R16, is developed by coupling a bioactive factor, parathyroid hormone related peptide 1 (PTHrP-1), to the basic supramolecular peptide RADA16-Ⅰ via solid-phase synthesis. It is found that P1R16 self-assembles into long nanofibers and co-assembles with RADA16-Ⅰ to form nanofiber hydrogels, thus coupling PTHrP-1 to hydrogel matrix. P1R16 nanofiber retains osteoinductive activity in a dose-dependent manner, and P1R16/RADA16-Ⅰ nanofiber hydrogels promote osteogenesis, angiogenesis and osteoclastogenesis in vitro and induce multi-functionalized osteoregeneration by intramembranous ossification and bone remodeling in vivo when loaded to collagen (Col) scaffolds. Abundant red blood marrow formation, ideal osteointegration and adapted degradation are observed in the 50% P1R16/Col scaffold group. Therefore, this study provides a promising strategy to develop multi-functional supramolecular peptides and a new method to topically administrate parathyroid hormone or parathyroid hormone related peptides for non-healing bone defects.

Fundamentals and Translational Applications of Stem Cells and Biomaterials in Dental, Oral and Craniofacial Regenerative Medicine

Regenerative dental medicine continuously expands to improve treatments for prevalent clinical problems in dental and oral medicine. Stem cell based translational opportunities include regenerative therapies for tooth restoration, root canal therapy, and inflammatory processes (e.g., periodontitis). The potential of regenerative approaches relies on the biological properties of dental stem cells. These and other multipotent somatic mesenchymal stem cell (MSC) types can in principle be applied as either autologous or allogeneic sources in dental procedures. Dental stem cells have distinct developmental origins and biological markers that determine their translational utility. Dental regenerative medicine is supported by mechanistic knowledge of the molecular pathways that regulate dental stem cell growth and differentiation. Cell fate determination and lineage progression of dental stem cells is regulated by multiple cell signaling pathways (e.g., WNTs, BMPs) and epigenetic mechanisms, including DNA modifications, histone modifications, and non-coding RNAs (e.g., miRNAs and lncRNAs). This review also considers a broad range of novel approaches in which stem cells are applied in combination with biopolymers, ceramics, and composite materials, as well as small molecules (agonistic or anti-agonistic ligands) and natural compounds. Materials that mimic the microenvironment of the stem cell niche are also presented. Promising concepts in bone and dental tissue engineering continue to drive innovation in dental and non-dental restorative procedures.

The efficacy of teriparatide (Cinnopar®) on bone repair in mandibular fractures: A single blinded randomized clinical trial

This study focused on the effects of teriparatide (CinnoPar) on healing and postoperative complications in mandibular bone fractures. In this single-blind randomized controlled trial, 30 patients with a mandibular fracture hospitalized for open reduction internal fixation were randomly assigned to the intervention (I) (n = 15) and control (C) (n = 15) groups. Both groups received daily acetaminophen and cephalexin for 1 week. For 1 month, Group I received daily subcutaneous teriparatide injections. The Radiographic Union Scale of the Mandible (RUSM) was used to assess mandibular bone fusion subjectively, and the Hounsfield unit (HU) was used to objectively assess radiodensity in a computed tomography (CT) scan. In both groups, the visual analog scale (VAS) score was used to assess postoperative complications such as pain, swelling, wound opening, pus secretion, and bitter taste. There was no significant difference in bone repair between the two groups in this study (P > 0.05). Teriparatide also had no effect on the postoperative complication rate in the control group (P > 0.05). Within the limitations of the study it seems that in mandibular fractures, teriparatide did not affect bone fusion or postoperative complications, so its use is not recommended for better bone fusion and fewer postoperative complications of mandibular fracture during the first month.

Parathyroid Hormone 1 Receptor Signaling in Dental Mesenchymal Stem Cells: Basic and Clinical Implications

Parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP) are two peptides that regulate mineral ion homeostasis, skeletal development, and bone turnover by activating parathyroid hormone 1 receptor (PTH1R). PTH1R signaling is of profound clinical interest for its potential to stimulate bone formation and regeneration. Recent pre-clinical animal studies and clinical trials have investigated the effects of PTH and PTHrP analogs in the orofacial region. Dental mesenchymal stem cells (MSCs) are targets of PTH1R signaling and have long been known as major factors in tissue repair and regeneration. Previous studies have begun to reveal important roles for PTH1R signaling in modulating the proliferation and differentiation of MSCs in the orofacial region. A better understanding of the molecular networks and underlying mechanisms for modulating MSCs in dental diseases will pave the way for the therapeutic applications of PTH and PTHrP in the future. Here we review recent studies involving dental MSCs, focusing on relationships with PTH1R. We also summarize recent basic and clinical observations of PTH and PTHrP treatment to help understand their use in MSCs-based dental and bone regeneration.