Attachment and growth of human osteoblasts on different biomaterial surfaces.

OBJECTIVES: To prove the biocompatibility of biomaterials applied in biomedical devices, in vitro testing is crucial to render a material fit for medical application. The material of choice for dental implants is commercially pure titanium (cp-Ti), while other materials such as zirconia and polyetheretherketone (PEEK) are considered highly promising due to their functional and esthetic properties. The aim of this study was to determine whether PEEK with defined mean surface roughness and composition could achieve results equal to titanium or zirconia. MATERIALS AND METHODS: Disks measuring 14 mm in diameter and 1 mm in thickness made from cp-Ti, yttria-stabilized zirconia (Y-TZP), and filled PEEK with a smooth surface finish were used for cell culture experiments. Human fetal osteoblasts (hFOB) were cultured in vitro on each material to observe changes after 1, 3, and 7 days regarding cell viability and lactate dehydrogenase (LDH) release. Additionally, mRNA expression of proliferative factors PCNA and Ki67 and cellular adhesion (vinculin mRNA expression and immunofluorescence staining) were analyzed after 3 days in the culture. RESULTS: In hFOB cultures, adhesion and viability were decreased on PEEK platelets, while LDH release remained stable. No significant difference was observed in cp-Ti and Y-TZP when compared to the control. CONCLUSIONS: The performance of cp-Ti and Y-TZP was equal to the control in all tests. It seems that highly polished PEEK in this particular composition cannot be recommended for osseointegrated implant applications due to decreased osteoblast attachment. Further investigations are recommended, especially in surface structures optimized for osseointegration.

Beneficial effect of methylprednisolone after mandibular third molar surgery: a randomized, double-blind, placebo-controlled split-mouth trial.

OBJECTIVES: Third molar (M3) removal is the model most frequently used for pain trials in oral surgery. Corticosteroids are frequently administered to reduce trismus and swelling after dentoalveolar surgical procedures. The purpose of this investigation was to evaluate the influence of a single, preoperative oral application of methylprednisolone on postoperative trismus, pain intensity, and the subjective need for analgesic medication after surgical removal of impacted mandibular M3 (LM3). MATERIALS AND METHODS: Sixteen healthy patients requiring similar bilateral surgical LM3 removal were included in a prospective, randomized, placebo-controlled, double-blind study in a split-mouth design. At random, each patient received either weight-dependent methylprednisolone (40-80 mg) or a placebo orally 1 h prior to surgery. In each case, the right and left LM3 were treated in independent visits. Trismus, swelling, pain measured on a 100-mm visual analog scale, and the postoperative demand of analgesics were assessed. RESULTS: Statistical analysis indicates a significant reduction of trismus, swelling, pain intensity, and patient-controlled intake of analgesics during the whole postsurgical period of investigation (first to seventh day). CONCLUSIONS: The results of this study suggest that a single preoperative weight-dependent administration of methylprednisolone is a safe and effective concept for diminishing postoperative discomfort, pain intensity, and the total intake of analgesics after wisdom tooth extractions. CLINICAL RELEVANCE: In case of missing contraindications, the preoperative administration of methylprednisolone is recommended, a routine medication for more extended procedures in oral surgery.