The effect of a bioactive collagen membrane releasing PDGF or GDF-5 on bone regeneration.

Regenerative procedures using barrier membrane technology are presently well established in periodontal/endodontic surgery. The objective of this study was to compare the subsequent effects of the released platelet-derived growth factor (PDGF) and growth/differentiation factor 5 (GDF-5) from collagen membranes (CMs) on bone regeneration in vitro and in vivo. In vitro studies were conducted using MC3T3-E1 mouse preosteoblasts cultured with or without factors. Cell viability, cell proliferation, alkaline phosphatase (ALP) activity and bone marker gene expression were then measured. In vivo studies were conducted by placing CMs with low or high dose PDGF or GDF-5 in rat mandibular defects. At 4 weeks after surgery new bone formation was measured using µCT and histological analysis. The results of in vitro studies showed that CM/GDF-5 significantly increased ALP and cell proliferation activities without cytotoxicity in MC3T3-E1 cells when compared to CM/PDGF or CM alone. Gene expression analysis revealed that Runx2 and Osteocalcin were significantly increased in CM/GDF-5 compared to CM/PDGF or control. Quantitative and qualitative µCT and histological analysis for new bone formation revealed that although CM/PDGF significantly enhanced bone regeneration compared to CM alone or control, CM/GDF-5 significantly accelerated bone regeneration to an even greater extent than CM/PDGF. The results also showed that GDF-5 induced new bone formation in a dose-dependent manner. These results suggest that this strategy, using a CM carrying GDF-5, might lead to an improvement in the current clinical treatment of bone defects for periodontal and implant therapy.

Cytokine therapy for craniosynostosis.

The birth prevalence of craniosynostosis (premature suture fusion) is 300-500 per 1,000,000 live births. Surgical management involves the release of the synostosed suture. In many cases, however, the suturectomy site rapidly reossifies, further restricts the growing brain and alters craniofacial growth. This resynostosis requires additional surgery, which increases patient morbidity and mortality. New findings in bone biology and molecular pathways involved with suture fusion, combined with novel tissue engineering techniques, may allow the design of targeted and complementary therapies to decrease complications inherent in high-risk surgical procedures. This paper selectively reviews recent advances in i) identifying genetic mutations and the aetiopathogenesis of a number of craniosynostotic conditions; ii) cranial suture biology and molecular biochemical pathways involved in suture fusion; and iii) the design, development and application of various vehicles and tissue engineered constructs to deliver cytokines and genes to cranial sutures. Such biologically based therapies may be used as surgical adjuncts to rescue fusing sutures or help manage postoperative resynostosis.

The effect of music distraction on pain, anxiety and behavior in pediatric dental patients.

PURPOSE: The purpose of this study was to determine if audio distraction could decrease patient anxiety, pain and disruptive behavior during pediatric dental procedures. METHODS: Forty-five children between the ages of 4 to 6 years had two visits each involving restorative dentistry with local anesthesia in a mandibular quadrant. Visit #1 was a baseline session for all patients. During visit #2, the children were assigned to either an upbeat music group, a relaxing music group or a no music group. Variables measured were: (1) parent-reported anxiety via the Modified Corah Anxiety Scale, (2) self-reported anxiety via the Venham picture scale, (3) heart rate, (4) behavior via the North Carolina Behavior Rating Scale and (5) pain via a visual analogue scale. RESULTS: No significant differences were found among the three groups during experimental visit #2 across any variables. A majority of patients (90%) stated that they enjoyed the music and would like to listen to it during their next visit. CONCLUSIONS: Audio distraction was not an effective means of reducing anxiety, pain or uncooperative behavior during pediatric restorative dental procedures. However, patients did enjoy listening to the music during their visits.