Periodontal wound healing with and without platelet-rich plasma: histologic observations and assessment of flap tensile strength.

BACKGROUND: Platelet-rich plasma (PRP) has been promoted as a surgical adjunct to enhance hard and soft tissue wound healing. Although anecdotally reported to be of value, the results of controlled studies examining the added effects of PRP on surgical procedures have been mixed. The purpose of this study was to test the effect of PRP on flap strength at various post-surgical time points in a minipig animal model. METHODS: Twelve Yucatan minipigs provided four sites per animal. PRP was prepared from each animal at the time of surgery. Following reflection of a mucoperiosteal flap in each quadrant, subgingival plaque and calculus were removed. Each surgical site was irrigated with sterile saline; prior to suturing, one randomly selected test quadrant in each arch was treated with PRP. Four animals were euthanized at day 14, and two animals were euthanized at 2, 7, 10, and 28 days. The flap strength in each quadrant was tested by attaching to a loop of 3-0 silk suture through the tissue; the force required to separate the flap from the tooth/bone interface was recorded for each site. A separate portion of each flap site was prepared for descriptive histologic examination, including inflammation, hemorrhage, and new bone growth. RESULTS: Flap strength was significantly less on day 2 compared to later time points, and there were no significant differences between the test and control groups. No histologic differences in healing between test and control sites were seen at any time point. CONCLUSIONS: PRP did not seem to contribute to greater flap strength at any post-surgical time point, nor was it associated with any histologic differences in wound healing in this Yucatan minipig model. The time points chosen for observation post-surgery, as well as the variability in the PRP platelet count, may have contributed to the lack of positive findings in this study.

Foreign body reaction to anorganic bovine bone and autogenous bone with platelet-rich plasma in guided bone regeneration.

BACKGROUND: Guided bone regeneration is frequently performed to augment deficient alveolar ridges. Although many materials may be used for these procedures, the outcome is usually predictable. In this report, we present an unusual reaction to a frequently used commercially available xenograft material. METHODS: A 36-year-old African American male was referred for restoration of edentulous space #8. Examination confirmed a ridge inadequate for implant placement without augmentation. A staged approach was chosen, with augmentation by a mixture of autogenous bone and anorganic bovine bone with platelet-rich plasma and a bioabsorbable collagen membrane. Healing was uneventful, although after 4 months, upon flap reflection, no regenerated hard tissue was found. The tissue at the site was submitted for histology, and the site was regrafted with an allograft/xenograft mixture and covered by a bioabsorbable collagen membrane. Wound healing was uneventful, and a histologic core was obtained at implant placement 5 months later. RESULTS: The initial histologic specimen consisted of a fibrous connective tissue matrix supporting islands of the anorganic bovine bone. The majority of the graft material demonstrated an intimate association with multinucleated foreign body-type giant cells. The histologic core obtained at the second procedure consisted of trabeculae of viable lamellar bone and associated fibrous connective tissue without a significant inflammatory cell infiltrate. Scattered particles of anorganic bovine bone were present, but no foreign body-type giant cells were identified. CONCLUSION: Failure of commonly used materials for guided bone regeneration is rare; however, different batches of materials may elicit varying immune responses in the recipient.

Palatal neurofibroma associated with localized periodontitis.

BACKGROUND: Neurofibromatosis type 1 (NF1) is the most common form of neurofibromatosis. While typically considered a dermatologic disorder, intraoral signs of neurofibromatosis occur quite commonly. This clinical entity can be confused with periodontitis because of the presence of periodontal pockets. In this report, we present the case of a palatal neurofibroma with radiographic involvement in a patient with NF1. METHODS: A 40-year-old female patient was referred from her general dentist to evaluate advanced periodontitis in the maxillary left quadrant. The patient's medical history was significant for a soft tissue lesion excised from her back 11 years previously and diagnosed as a neurofibroma. Subsequent medical examination at that time confirmed a systemic diagnosis of NF1. A comprehensive periodontal evaluation was performed, and panoramic and periapical radiographs were taken. Teeth were tested for vitality. An incisional biopsy was completed for histopathologic examination. RESULTS: The periodontal evaluation revealed the presence of 6 to 9 mm probing depths adjacent to teeth #14 and #15. Panoramic and periapical radiographs showed a circumscribed 0.8x0.9-cm unilocular radiolucency superimposed over the root of tooth #13 and extensive horizontal bone loss on the distal side of #15. Incisional biopsy confirmed the presence of a neurofibroma, and because of the extent of the lesion, the patient was referred to the Oral and Maxillofacial Surgery service for complete excision. CONCLUSIONS: Neurofibromas can cause extensive destruction of alveolar bone, mimicking periodontitis. Due to the potential systemic and genetic implications, the diagnosis of neurofibroma requires appropriate medical referral.