Healing outcomes of open versus closed flap procedures for collagen membrane coverage following immediate dental implant placements with simultaneous guided tissue regeneration.

OBJECTIVE: To compare the outcomes of open healing to complete closure for collagen membrane coverage for immediate implant placements with simultaneous guided bone regeneration (GBR) in two retrospective cohorts. METHODS: The subjects included 118 patients who received Bio-Gide® collagen membrane coverage for immediate implant placements and GBR in 20 anterior and 98 posterior teeth. For 58 patients, gingival flaps were released to achieve full coverage of collagen membrane (CC group). For 60 patients, no efforts were made to release the gingival flaps and collagen membrane was left exposed for open healing (OH group). Antibiotics and analgesics were prescribed for 7 days after surgery. The width of crestal open wounds were measured after surgery (W0), and at 1, 2 and 16 weeks (W16). Changes in bone mass were assessed by cone-beam computed tomography after implant placement and again at W16. Gingival and bone tissues over the implant cover screws were harvested and assessed for 16 patients in the OH group at W16. RESULTS: No wound dehiscence occurred in the CC group from W0 to W16. Both the vertical and horizontal bone dimension changes were not significantly different between the OH and CC group. For the OH group, soft tissue was completely healed at W16 when the initial wound widths were ≤6 mm. For those with initial wound widths ≥ 7 mm, the cover screws were exposed in 5/16 patients at W16 but did not affect the final restorations. Tissue staining showed keratinized mucosa and new bone formation above the dental implant in the OH group. CONCLUSION: Open healing achieved healing outcomes similar to those of complete closure for collagen membrane coverage following immediate implant placements. CLINICAL SIGNIFICANCE: For immediate implant placement requiring bone grafting and collagen membrane coverage, it is unnecessary to release the gingival flaps or use tissue grafts to achieve full coverage of the crestal wounds. Open healing with exposed membrane could achieve similar outcomes with less pain and swelling.

Preliminary study of the impact of elevated circulating plasma levels of catecholamines on opioid requirements for acute surgical pain.

INTRODUCTION: The objective of this study is to determine whether elevated circulating plasma catecholamine levels significantly impact opioid requirements during the first 24 hours postoperative period in individuals with acute surgical pain. METHODS: We retrospectively reviewed 15 electronic medical records (EMRs) from adults 18 years and older, with confirmed elevated plasma catecholamine levels (experimental) and 15 electronic health records (EHRs) from matched-controls for age, gender, race and type of surgery, with a follow up of 24 hours postoperatively. RESULTS: The total morphine milligram equivalents (MMEs) requirements from the experimental group were not statistically different when compared with controls [44.1 (13 to 163) mg versus 47.5 (13 to 151) mg respectively; p 0.4965]. However, the intraoperative MMEs showed a significant difference, among the two groups; [(experimental) 32.5 (13. to 130) mg, (control) 15 (6.5 to 130) mg; p 0.0734]. The intraoperative dosage of midazolam showed a highly significant positive correlation to the total MMEs (p 0.0005). The subjects with both elevated plasma catecholamines and hypertension used significantly higher intraoperative MMEs compared to controls [34.1 (13 to 130) mg versus 15 (6.5 to 130) mg, respectively; p 0.0292)]. Those 51 years and younger, with elevated circulating levels of catecholamines, required significantly higher levels of both the postoperative MMEs [29.1 (0 to 45) mg versus 12 (0 to 71.5) mg; (p 0.0553)] and total MMEs [544.05 (13 to 81) mg versus 29.42 (13 to 92.5) mg; (p 0.00018), when compared to controls with history of nicotine and alcohol use. CONCLUSION: This preliminary study evaluated a biologic factor, which have promising clinical usefulness for predicting analgesic requirements that can drive clinical decisions on acute surgical pain.

Pathogenesis, diagnosis and management of dentin hypersensitivity: an evidence-based overview for dental practitioners.

Though dentin hypersensitivity (DHS) is one of the most common complaints from patients in dental clinics, there are no universally accepted guidelines for differential diagnosis as well as selection of reliable treatment modalities for this condition. The neurosensory mechanisms underlying DHS remain unclear, but fluid movements within exposed dentinal tubules, i.e., the hydrodynamic theory, has been a widely accepted explanation for DHS pain. As several dental conditions have symptoms that mimic DHS at different stages of their progression, diagnosis and treatment of DHS are often confusing, especially for inexperienced dental practitioners. In this paper we provide an up-to-date review on risk factors that play a role in the development and chronicity of DHS and summarize the current principles and strategies for differential diagnosis and management of DHS in dental practices. We will outline the etiology, predisposing factors and the underlying putative mechanisms of DHS, and provide principles and indications for its diagnosis and management. Though desensitization remains to be the first choice for DHS for many dental practitioners and most of desensitizing agents reduce the symptoms of DHS by occluding patent dentinal tubules, the long-term outcome of such treatment is uncertain. With improved understanding of the underlying nociceptive mechanisms of DHS, it is expected that promising novel therapies will emerge and provide more effective relief for patients with DHS.

[Adsorption Characteristics and Mechanism of Cadmium in Water by Alkali and Magnetic Composite Modified Wheat Straw Biochar].

Wheat straw biochar (BC) was modified by KOH and magnetics to generate composited modified biochar (FKC). Based on characterization by scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), Brunauer-Emmett-Teller (BET), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and magnetic (VSM) techniques, the adsorption characteristics and mechanisms of Cd2+ in water and the effects of temperature, pH value, and dosage on the adsorption characteristics of FKC were studied. The results showed that the modified biochar was loose and porous. The specific surface area of FKC increased by 19.11 times, the number of aromatic and oxygen-containing functional groups such as O-H, C=O, and C=C increased, and a new functional group Fe-O formed compared to the BC. FKC is magnetic, and its magnetization is 8.43 emu·g-1, which can be recycled and reused. The adsorption of Cd2+ by FKC fitted well with the pseudo-second-order kinetic model and the Langmuir model, indicating that chemical adsorption is the main adsorption mechanism. The theoretical maximum equilibrium adsorption capacity of FKC is 23.44 mg·g-1, which is 1.47 times that of BC. The thermodynamic parameters suggested the adsorption of Cd2+ by FKC was a spontaneous and endothermic process. The adsorption capacity increased with an increase of pH in the region 2-8, and a biochar dosage of 10 g·L-1 was used. After three cycles of adsorption-desorption-adsorption, the adsorption capacity of Cd2+ by FKC still reached 17.71 mg·g-1, indicating that FKC has good reusability. These results can provide a theoretical basis for the application of KOH and magnet-modified biochar from wheat straw to remove heavy metals from contaminated wastewater.

Interferon-γ regulates the function of mesenchymal stem cells from oral lichen planus via indoleamine 2,3-dioxygenase activity.

BACKGROUND: Little is known about mesenchymal stem cells (MSCs) in normal or inflammatory oral mucosal tissues, such as in oral lichen planus (OLP). Our objectives were to identify, isolate, and characterize MSCs from normal human oral mucosa and OLP lesions, and to evaluate indoleamine 2,3 dioxygenase (IDO) activity in mediating immunomodulation of MSCs from these tissues. METHODS: Expressions of MSCs-related markers were examined in isolated cells by flow cytometry. Self-renewal and multilineage differentiations were studied to characterize these MSCs. Interferon-γ (IFN-γ), IDO, and STRO-1 were assessed by immunofluorescence. MSCs from oral mucosa and OLP or IFN-γ-pretreated MSCs were co-cultured with allogeneic mixed lymphocyte reaction assays (MLR). Proliferation and apoptosis of MLR or MSCs were detected by CCK8 and the annexin V-FITC apoptosis detection kit, respectively. IDO expression and activity were measured by real-time PCR, Western blotting, and high-performance liquid chromatography. RESULTS: Isolated cells from oral mucosa and OLP expressed MSC-related markers STRO-1, CD105, and CD90 but were absent for hematopoietic stem cell markers CD34. Besides, they all showed self-renewal and multilineage differentiation capacities. MSCs in OLP presented STRO-1/IDO+ phenotype by immunofluorescence. MSCs and IFN-γ-pretreated MSCs could inhibit lymphocyte proliferation via IDO activity, but not via cell apoptosis. Long-term IFN-γ could also inhibit MSC proliferation via IDO activity. CONCLUSIONS: Mesenchymal stem cells can be isolated from human oral mucosa and OLP tissues. Besides self-renewal and multilineage differentiation properties, these cells may participate in immunomodulation mediated by IFN-γ via IDO activity in human OLP.

Porous collagen-hydroxyapatite scaffolds with mesenchymal stem cells for bone regeneration.

Current bone grafting materials have significant limitations for repairing maxillofacial and dentoalveolar bone deficiencies. An ideal bone tissue-engineering construct is still lacking. The purpose of the present study was first to synthesize and develop a collagen-hydroxyapatite (Col-HA) composite through controlled in situ mineralization on type I collagen fibrils with nanometer-sized apatite crystals, and then evaluate their biologic properties by culturing with mouse and human mesenchymal stem cells (MSCs). We synthesized Col-HA scaffolds with different Col:HA ratios. Mouse C3H10T1/2 MSCs and human periodontal ligament stem cells (hPDSCs) were cultured with scaffolds for cell proliferation and biocompatibility assays. We found that the porous Col-HA composites have good biocompatibility and biomimetic properties. The Col-HA composites with ratios 80:20 and 50:50 composites supported the attachments and proliferations of mouse MSCs and hPDSCs. These findings indicate that Col-HA composite complexes have strong potentials for bone tissue regeneration.

Role of clinician's experience and implant design on implant stability. An ex vivo study in artificial soft bones.

OBJECTIVES: Clinical experience in implant placement is important in order to prevent implant failures. However, the implant design affects the primary implant stability (PS) especially in poor quality bones. Therefore, the aim of this study was to compare the effect of clinician surgical experience on PS, when placing different type of implant designs. METHODS: A total of 180 implants (90 parallel walled-P and 90 tapered-T) were placed in freshly slaughtered cow ribs. Bone quality was evaluated by two examiners during surgery and considered as 'type IV' bone. Implants (ø 5 mm, length: 15 mm, Osseotite, BIOMET 3i, Palm Beach Gardens, FL, USA) were placed by three different clinicians (master/I, good/II, non-experienced/III, under direct supervision of a manufacturer representative; 30 implants/group). An independent observer assessed the accuracy of placement by resonance frequency analysis (RFA) with implant stability quotient (ISQ) values. Two-way analysis of variance (ANOVA) and Tukey's post hoc test were used to detect the surgical experience of the clinicians and their interaction and effects of implant design on the PS. RESULTS: All implants were mechanically stable. The mean ISQ values were: 49.57(± 18.49) for the P-implants and 67.07(± 8.79) for the T-implants. The two-way ANOVA showed significant effects of implant design (p < .0001), clinician (p < .0001), and their interaction (p < .0001). The Tukey's multiple comparison test showed significant differences in RFA for the clinician group I/II (p = .015) and highly significant (p < .0001) between I/III and II/III. The P-implants presented (for I, II, and III) mean ISQ values 31.25/49.18/68.17 and the T-implants showed higher ISQ values, 70.15/62.08/68.98, respectively. Clinicians I and II did not show extreme differences for T-implants (p = .016). In contrast, clinician III achieved high ISQ values using P- and T-implants following the exact surgical protocol based on the manufacturer guidelines. T-implants provided high stability for experienced clinicians compared with P-implants. CONCLUSION: T-implants achieved greater PS than the P-implants. All clinicians consistently achieved PS; however, experienced clinicians achieved higher ISQ values with T-implants in poor quality bone.

Total laparoscopic hysterectomy versus total abdominal hysterectomy for endometrial cancer: a meta-analysis.

The standard surgery for early-stage endometrial cancer is total abdominal hysterectomy (TAH), while total laparoscopic hysterectomy (TLH) is less invasive and assumed to be associated with lower morbidity. This meta- analysis was performed to investigate the effects of TLH versus TAH in women with early-stage endometrial cancer. We searched the PubMed, EMBASE, CBM and Cochrane Review databases for randomized trials assessing the effects of TLH versus TAH in women with early-stage endometrial cancer. The relative risks (RR) with 95% confidence intervals (CIs) from each study were pooled using meta-analysis. In our study, 9 randomized trials with a total of 1,263 patients were included. Meta-analyses showed that TLH was associated with lower risks of major complications (RR = 0.53, 95%CI 0.29-0.98, P = 0.042), total complications (RR = 0.59, 95%CI 0.42-0.82, P = 0.002) and postoperative complications (RR = 0.57, 95%CI 0.40-0.83, P = 0.003). However, there were no obvious differences in risks of intra-operative complications (RR = 0.98, 95%CI 0.62-1.55, P = 0.919) and mortality (RR = 0.96, 95%CI 0.66-1.40, P = 0.835). In conclusion, our results provide new evidence of a benefit for TLH over TAH in terms of major complications, total complications and postoperative complications in endometrial cancer patients.

HDAC6 siRNA inhibits proliferation and induces apoptosis of HeLa cells and its related molecular mechanism.

OBJECTIVE: To investigate the effects of histone deacetylase 6 (HDAC6) siRNA on cell proliferation and cell apoptosis of the HeLa cervical carcinoma cell line and the molecular mechanisms involved. METHODS: Division was into three groups: A, the untreated group; B, the control siRNA group; and C, the HDAC6 siRNA group. Lipofectamine 2000 was used for siRNA transfection, and Western blot analysis was used to determine the protein levels. Cell proliferation and apoptosis were characterized using a CCK-8 assay and flow cytometry, respectively. RESULTS: HDAC6 protein expression in the HDAC6 siRNA-transfection group was significantly lower (P < 0.05) than in the untreated and control siRNA groups. The CCK-8 kit results demonstrated that the proliferation of HeLa cells was clearly inhibited in the HDAC6 siRNA transfection group (P < 0.05). In addition, flow cytometry revealed that the early apoptotic rate (26.0% ± 0.87%) was significantly elevated (P < 0.05) as compared with the untreated group (10.6% ± 1.19%) and control siRNA group (8.61% ± 0.98%). Furthermore, Western blot analysis indicated that bcl-2 protein expression in the HDAC6 siRNA-transfection group was down-regulated, whereas the expression of p21 and bax was up-regulated. CONCLUSION: HDAC6 plays an essential role in the occurrence and development of cervical carcinoma, and the down-regulation of HDAC6 expression may be useful molecular therapeutic method.

Platelet-rich plasma: a literature review.

Platelet-rich plasma (PRP) is an autologous concentration of platelets in concentrated plasma, which is extensively used to promote soft and hard tissue healing. The significance behind its use refers to the abundance of growth factors present in a well-prepared PRP concentrate. These growth factors enhance the rate and quality of wound healing by different mechanisms. The objective of this review article is to explain the biological aspect of hard and soft tissue healing by application of PRP in conjunctions with its molecular basis.

Effectiveness of antibiotic prophylaxis in third molar surgery: a meta-analysis of randomized controlled clinical trials.

PURPOSE: We conducted a synthetic quantitative review of the published clinical trials on the effectiveness of antibiotic prophylaxis in third molar surgery. MATERIALS AND METHODS: Electronic databases were searched for randomized controlled trials. The primary outcome variables included alveolar osteitis (AO) and surgical wound infection. The extracted data were analyzed using a meta-analytical program with a random-effect model. Number needed to treat (NnT) was calculated. RESULTS: A total of 2,932 patients randomized in 16 clinical trials reported AO as an outcome. AO occurred in 84 of 1,350 patients in the treatment group, a frequency of 6.2%; and in 228 of 1,582 patients in the control group, a frequency of 14.4%. Systemic antibiotic therapy was effective in reducing the risk of AO (odds ratio [OR], 2.175) with an NnT of 13. A total of 2,396 patients randomized in 12 clinical trials reported wound infection as an outcome. Wound infection occurred in 44 of 1,110 patients in the treatment group, a frequency of 4%; and in 78 of 1,286 patients in the control group, a frequency of 6.1%. Systemic antibiotic therapy was effective in reducing the risk of wound infection (OR, 1.794) with an NnT of 25. Antibiotics reduced the risk of AO and wound infection only when first dose was given before surgery. CONCLUSIONS: Systemic antibiotics given before the surgery were effective in reducing the frequencies of AO and wound infection after third molar surgery.

Rapid quantitative determination of C-reactive protein at chair side in dental emergency patients.

OBJECTIVES: The objective of this study was to quantitatively determine, at chair side, the serum C-reactive protein (CRP) levels in dental emergency patients. STUDY DESIGN: Quantitative CRP test was performed at chair side in 40 patients with acute alveolar abscess (AAA), acute periodontal abscess (APA), and alveolar osteitis (AO) at the time of dental emergency treatment and 1 week after. CRP levels were compared between groups and before and after treatments using ANOVA and Fisher's Exact tests. RESULTS: Serum CRP levels were greater than 5 mg/L in 30 (75%) of the 40 patients. At 1-week follow-up, the decline in CRP levels was evident in the AAA group (P < .05), but not statistically significant in the APA and AO groups (P > .05). CONCLUSION: Serum CRP levels are often elevated in patients with odontogenic infections and postoperative complications. Rapid reduction in serum CRP levels was likely to occur following successful treatment of AAA, but less likely to occur in APA and AO.