Trap door: an alternative procedure to the triangular distal wedge for the elimination of distal periodontal pockets adjacent to edentulous areas.

The study compared a novel trap door (TD) technique with the triangular distal wedge (TW) procedure for the elimination of distal periodontal pockets adjacent to edentulous areas. Thirteen patients with suprabony pockets ≥ 5 mm at the distal surface of terminal molars bilaterally were included in this prospective, single-blinded, randomized clinical trial using a split-mouth design. The authors demonstrated the efficacy of an alternative TD technique in the elimination of the distal pockets adjacent to the terminal molars.

Desquamative gingivitis as a manifestation of chronic mucocutaneous disease.

Desquamative gingivitis (DG) is a clinical descriptive term indicating "peeling gums". DG is usually the result of a disease process that causes separation of the epithelium from the underlying connective tissue in the oral masticatory mucosa. DG may be a manifestation of several mucocutaneous diseases, most commonly cicatricial pemphigoid, pemphigus vulgaris and lichen planus. Correct diagnosis of the underlying disease in DG patients requires careful clinical observation, detailed examination of medical history, biopsy and histopathological examination of the lesions as well as more specialized tests such as direct and indirect immunofluorescence. Treatment of DG consists of treating the underlying disease and often requires the use of immunosuppressive agents, such as corticosteroids. Elimination of local gingival irritants, such as dental plaque and calculus, can significantly improve the treatment outcome.

Severe periodontitis in a patient with hyperoxaluria and oxalosis: a case report and review of the literature.

BACKGROUND: Hyperoxaluria is a metabolic disease with excessive urinary oxalate excretion that can be primary or secondary. Hyperoxaluria can result in chronic renal disease and renal failure. Calcium oxalate crystals can be deposited in oral tissues, and the disease can be associated with severe periodontitis and tooth loss. METHODS: The periodontal condition of a 38-year-old patient with a diagnosis of hyperoxaluria and end-stage renal disease is presented. The patient's periodontal status was monitored over a period of several weeks, and extracted teeth were submitted for histopathologic evaluation. RESULTS: The patient was diagnosed with generalized severe periodontitis and external root resorption. Initial periodontal treatment consisting of oral-hygiene instructions and scaling and root planing was performed. However, despite an initial decrease of soft tissue inflammation, the patient's periodontal condition deteriorated, and eventually, all teeth had to be extracted. The deposition of calcium oxalate crystals in the periodontal tissues was confirmed histologically. CONCLUSIONS: Long-standing hyperoxaluria can be associated with severe periodontitis and external root resorption resulting in tooth loss. The pathogenetic mechanisms of hard tissue destruction are still unclear.

Expression of MMP-13 (collagenase-3) in long-term cultures of human dental pulp cells.

UNLABELLED: Matrix metalloproteinase-13 (MMP-13 or collagenase-3) is a member of the family of matrix metalloproteinases (MMPs) produced in high amounts by cells with mineralising potential. Human dental pulp has been shown to express high levels of MMP-13 RNA. OBJECTIVE: Since human dental pulp derived cells (HDPC) are known to possess osteoprogenitor properties, we investigated the pattern of expression of MMP-13 in long-term cultures of those cells under conditions that support mineralisation in vitro. DESIGN: Impacted teeth or teeth extracted for orthodontic purposes were used to obtain dental pulp explants and HDPC were cultured for approximately 5 weeks. Pro- and active MMP-13 levels were determined in the cell culture supernatants by means of enzyme-linked immunosorbent assay (ELISA). Cell growth was evaluated through DNA content and osteogenic differentiation was assessed by alkaline phosphatase (ALP) activity and Alizarin Red staining. RESULTS: Mineralising cultures of HDPC produced significantly higher levels of pro-MMP-13 compared to control cultures. Both pro- and active MMP-13 levels displayed a characteristic peak that was found to coincide with the peak in alkaline phosphatase activity and the onset of mineralisation. Once mineralisation was firmly established, MMP-13 expression was significantly reduced. CONCLUSIONS: Evidence from this study suggests a role for MMP-13 in the transition of human dental pulp cells to a mature mineralising phenotype and points to MMP-13 as a possible marker in HDPC differentiation.

The effect of a selective cyclooxygenase-2 inhibitor (celecoxib) on chronic periodontitis.

BACKGROUND: Non-steroidal anti-inflammatory agents inhibit the production of cyclooxygenase (COX) products and can attenuate bone loss. In this double-masked, placebo-controlled, randomized clinical trial, the efficacy of celecoxib (COX-2 inhibitor) was evaluated in conjunction with scaling and root planing (SRP) in subjects with chronic periodontitis (CP). METHODS: A total of 131 subjects were randomized to receive SRP and either celecoxib (200 mg) or placebo every day for 6 months. Clinical outcomes were assessed every 3 months for 12 months as mean changes from baseline. Primary efficacy parameters included clinical attachment level (CAL) and probing depth (PD). Secondary outcomes included percentages of tooth sites with CAL loss or gain > or =2 mm, changes in bleeding on probing (BOP), plaque index, and mobility. Prior to analysis, tooth sites were grouped based on baseline PD as shallow (1 to 3 mm), moderate (4 to 6 mm), or deep (> or =7 mm). RESULTS: Mean PD reduction and CAL gain were greater in the celecoxib group, primarily in moderate and deep sites, throughout the study (PD: 3.84 mm versus 2.06 mm, P <0.001; CAL: 3.74 mm versus 1.43 mm, P <0.0001 for deep sites at 12 months). The celecoxib group also exhibited a greater percentage of sites with > or =2 mm CAL gain and fewer sites with > or =2 mm CAL loss. Both groups showed improved plaque control and BOP scores. Demographic, social, and behavioral factors did not affect treatment outcomes. CONCLUSIONS: Celecoxib can be an effective adjunctive treatment to SRP to reduce progressive attachment loss in subjects with CP. Its beneficiary effect persisted even at 6 months postadministration. However, given the increased cardiovascular risks associated with the use of this drug, close patient supervision and strict adherence to dosage and administration guidelines established by the Unites States Food and Drug Administration are of paramount importance.

Osteogenic differentiation of human mesenchymal bone marrow cells in silk scaffolds is regulated by nitric oxide.

Bone marrow-derived mesenchymal stem cells (BMSC) are a powerful tool for tissue engineering and can be used in the regeneration of bone and other tissues. Nitric oxide (NO) produced by the endothelial NO synthase (eNOS) plays an important role in bone development and healing. We hypothesized that NO plays a role in osteogenic differentiation of BMSC cultured in three-dimensional silk scaffolds. eNOS protein was measured by Western Analysis and its activity was assessed by measuring nitrite in culture supernatants. Mineralization was evaluated through calcium deposition and the expression of genes associated with osteogenic differentiation (collagen I, RUNX2, and osteocalcin) was quantified using real-time RT-PCR. eNOS was consistently expressed with minor fluctuations, but NO production significantly increased at later time points (weeks 4 and 5). Addition of a competitive NOS inhibitor (L-NAME) resulted in a modest decrease in calcium deposition, which became statistically significant in week 5. This was preceded by a dramatic decrease in RUNX2 and osteocalcin expression in week 4. These results support our hypothesis and implicate NO as an important player in bone tissue engineering.

Expression of stem cell factor and its receptor, c-kit, in human oral mesenchymal cells.

Stem cell factor (SCF) is the pleiotropic ligand for the tyrosine kinase receptor, c-kit. Ligand and receptor are usually expressed in different cell types, and binding of SCF to c-kit promotes cell proliferation, differentiation, and recruitment of progenitor cells in various biologic systems. However, the localization of these two molecules in cells of the oral cavity has not been systematically examined. We investigated the expression of SCF and c-kit in human dental pulp (HDP) cells as well as in human gingival fibroblasts (HGF). Both alternatively spliced isoforms of SCF were detected (through reverse transcription-polymerase chain reaction) in RNA obtained from the two cell types. Western analysis established that both cell types express SCF and/or c-kit, whereas flow cytometry demonstrated distinct cell populations expressing only the ligand (SCF), only the receptor (c-kit), or co-expressing the two. HDP cultures showed higher soluble SCF (sSCF) production associated with faster cell growth, as compared with HGF cultures. In both cell types, however, sSCF levels appeared to increase as a result of in vitro aging and/or differentiation.

Quantitative evaluation of bone density using the Hounsfield index.

PURPOSE: The primary aims of this retrospective study were to: (1) evaluate bone quality in different segments of the edentulous jaw and correlate it with demographic data and (2) establish a quantitative and objective assessment of bone quality based on the Hounsfield scale. MATERIALS AND METHODS: One hundred one randomly selected computerized tomographic (CT) scans were used for the analysis. Edentulous segments ranging from 10 to 30 mm were selected for evaluation, and the findings were analyzed and correlated to demographics. Implant recipient sites were evaluated visually for bone classification by 2 independent examiners. The same sites were subsequently evaluated digitally using the Hounsfield scale, and the results were correlated with the visual classification. RESULTS: The 4 quadrants of the mouth displayed Hounsfield unit (HU) values ranging from -240 HU to 1,159 HU. The highest unit/mean density value (559 +/- 208 HU) was found in the anterior mandible, followed by 517 +/- 177 HU for the anterior maxilla, 333 +/- 199 HU for the posterior maxilla, and 321 +/- 132 HU for the posterior mandible. There was no association between the Hounsfield value and density and age or gender. When subjective bone quality was correlated to Hounsfield index findings, only the relationship between HU and type 4 bone was found to be significant. CONCLUSIONS: Knowledge of the Hounsfield value as a quantitative measurement of bone density can be helpful as a diagnostic tool. It can provide the implant surgeon with an objective assessment of bone density, which could result in modification of surgical techniques or extended healing time, especially in situations where poor bone quality is suspected.

Postoperative complications following gingival augmentation procedures.

BACKGROUND: Postoperative pain, swelling, and bleeding are the most common complications following soft tissue grafting procedures; however, detailed documentation is sparse in the literature. The aims of this prospective study were as follows: 1) to compare the frequency of complication occurrence after free soft tissue grafting (FSTG) or subepithelial connective tissue grafting (SCTG) procedures; 2) to evaluate the use of an acellular dermal matrix (ADM) as the donor tissue alternative to an FSTG or SCTG; and 3) to identify possible predictors for these complications. METHODS: Seventy-five FSTG and 256 SCTG procedures were performed in 228 patients by a single operator. In five free soft tissue and 84 bilaminar graft procedures, an ADM was used instead of autogenous tissue. Variables such as the duration and location of procedures, smoking history, gender, and age were recorded. Patients were asked to fill out a questionnaire 1 week after the surgeries regarding postoperative pain, swelling, and bleeding. Data were analyzed using the chi2 test and logistic regression analysis. Odds ratios were calculated for moderate and severe adverse outcomes grouped together. RESULTS: The duration of surgical procedures was highly correlated with pain or swelling post-surgically (P = 0.001). Current smokers were three times more likely to experience post-surgical swelling (P = 0.01). Patients who underwent FSTG procedures were three times more likely to develop post-surgical pain (P = 0.002) or bleeding (P = 0.03) compared to those who received SCTG procedures. When an ADM was applied instead of autogenous tissue, the probability of swelling or bleeding was significantly reduced (odds ratio [OR] = 0.46, P = 0.02 and OR = 0.3, P = 0.001, respectively). CONCLUSIONS: Long surgical procedures and smoking may increase the severity and frequency of certain post-surgical complications after gingival augmentation procedures. FSTG procedures incur a higher likelihood for postoperative pain or bleeding than SCTG procedures, whereas the application of an ADM may significantly reduce the probability of swelling and bleeding.

Clinical significance of the structural integrity of the superior aspect of the mandibular canal.

BACKGROUND: Sparse data can be found regarding the structural integrity of the superior aspect of the mandibular canal. In many cases, the mandibular canal must be carefully evaluated prior to defining patient treatment. METHODS: In this case report, a 54-year-old patient presented with a periapical infection involving the mesial root of the mandibular right second molar (#31). Radiographic evaluation revealed that the periapical lesion extended from the apex of the tooth to the superior aspect of the mandibular canal. Upon surgical removal of the tooth, an apical communication between the extraction socket and mandibular nerve was located. A guided bone regeneration procedure was performed to protect the nerve from subsequent damage and to prepare the site for future implant placement. Implants were placed in the area approximately 5 months following the regenerative procedure. RESULTS: After implant placement, the patient experienced normal function and no mandibular symptomatology. Implants have been in function for the past 4 years. CONCLUSIONS: Many factors, both pathologic and developmental, can lead to a discontinuity of the superior aspect of the mandibular canal. Normally, a thin cortical plate of bone protects the nerve. When a lack of structural integrity of the canal roof is discovered, enucleation of a periapical infection or subsequent implant placement can lead to potential disruption of the nerve. Limited information is available regarding the integrity of this protective cover. This case report underscores the importance of proper clinical diagnosis before implant placement in the posterior mandible.