In situ shell technique for edentulous ridge augmentation.

BACKGROUND: The novel two-stage technique presented in this study is based on guided bone regeneration for three-dimensional bone augmentation. METHODS AND RESULTS: The proposed technique was performed to augment an atrophic alveolar ridge in the maxilla and mandible. This method is based on using an autogenous bone plate, a mixture of allogeneic bone graft and injectable -platelet-rich fibrin, and a bioresorbable barrier membrane. Based on the cases presented in this study, sufficient osseous regeneration was achieved to place dental implants in an ideal position. CONCLUSION: Within the limitations of the present study, it seems that in situ shell technique could be a beneficial method to augment the extremely atrophied ridges with less morbidity and shorter operative time. KEY POINTS: Why is this case new information? The cases presented a new technique using in situ autogenous plates for ridge augmentation. What are the keys to the successful management of this case? The keys to the successful management of these cases are proper flap management and less traumatic bony plate preparation. What are the primary limitations to success in this case? The primary limitation to success in this technique would be a need for high surgical skills to conduct the procedure accurately.

Effect of epigallocatechin-3-gallate on tumor necrosis factor-alpha production by human gingival fibroblasts stimulated with bacterial lipopolysaccharide: An in vitro study.

BACKGROUND: Evidence shows that epigallocatechin-3-gallate (EGCG) in green tea has anti-inflammatory effects. AIM: This study assessed the effect of EGCG on the production of tumor necrosis factor-alpha (TNF-α) as an inflammatory cytokine in periodontitis, which produced by human gingival fibroblasts (HGFs) stimulated with lipopolysaccharide (LPS) of Porphyromonas gingivalis. MATERIALS AND METHODS: In this study, HGFs were cultured and subjected to LPS and EGCG. Cell viability of different concentrations of EGCG (10, 25, 50, 75, and 100 µM) and LPS (1, 10, 20, and 50 µg/mL) was assessed using methyl-thiazole-tetrazolium (MTT) assay. Then, the best concentrations of EGCG and P. gingivalis LPS were used simultaneously and separately to assess the production of TNF-α by HGFs using the enzyme-linked immunosorbent assay (ELISA). Assessments were done at 1, 3, and 5 days. Data were read using the ELISA reader and analyzed by the SPSS through two-way ANOVA. RESULTS: LPS at 1, 10, and 20 and EGCG at 10.25 and 50 µM showed the least cytotoxicity in MTT assay. ELISA showed EGCG alone decreased the production of TNF-α in all days, except 10 µM on day 1. 1, 10, and 20 µg/mL LPS increased the output of TNF-α on days 1 and 3 while reducing it on day 5. The combination of EGCG and LPS showed a decrease of TNF-α in all days except on day 5 that revealed an increase in the production of TNF-α at 25 and 50 µM EGCG. CONCLUSION: In the combination use of EGCG and LPS, EGCG shows anti-inflammatory effects by decreasing the production of TNF-α by HGFs stimulated with P. gingivalis.

Effects of leukocyte-platelet-rich fibrin and advanced platelet-rich fibrin on the viability and migration of human gingival fibroblasts.

BACKGROUND: Platelet products play a fundamental role in the process of healing. The new generation of platelet-rich fibrin (PRF), namely advanced PRF (A-PRF), has different biological and mechanical properties compared to those of leukocyte-PRF (L-PRF). This study aimed to compare the effects of L-PRF and A-PRF on the viability and migration of human gingival fibroblasts (HGFs). MATERIALS AND METHODS: In this in vitro study, the effects of A-PRF and L-PRF on the viability and migration of HGFs after 24 and 48 h were evaluated using the methyl thiazolyl tetrazolium assay. The viability of the negative control culture medium was considered to be 100%. The mean optical density of the test groups was divided by that of the negative control group and reported as percentage. One-way ANOVA was applied to assess the effects of time and type of PRF on the viability and migration of HGFs. Pairwise comparisons were made using the Tukey's test. RESULTS: At 24 h, cell viability in the L-PRF group was significantly higher than that in the A-PRF group (P < 0.05). However, no significant difference was noted between the two groups at 48 h. At 24 h, L-PRF caused significantly higher cell migration compared to the negative control group, whereas at 48 h, both A-PRF and L-PRF significantly increased cell migration compared to the control group. CONCLUSION: Within the limitations of this study, L-PRF and A-PRF had significant effects on the viability and migration of HGFs. Further studies on these platelet concentrates are warranted.

Periostin levels in saliva of patients with chronic periodontitis.

BACKGROUND: Periostin acts as a necessary protein for tissue integrity and maturity and has a key role as a modulator of periodontal ligament hemostasis. It has been shown that periostin acts as a supportive protein. The aim of this study was to compare the concentration of periostin in the saliva of patients with chronic periodontitis and healthy controls. MATERIALS AND METHODS: In this case-control, cross-sectional study, a total of 45 individuals (25 patients with chronic periodontitis and 20 healthy controls) were evaluated. Whole saliva samples were collected, and periostin levels were evaluated by standard enzyme-linked immunosorbent assay. The results were analyzed by SPSS and Mann-Whitney analysis. RESULTS: The results of this study showed that the level of periostin in saliva in patients with periodontitis was significantly lower than healthy controls (P < 0.05). Periostin was detectable in all samples. CONCLUSION: The results show that there is a significant relationship between the level of periostin in saliva and chronic periodontitis. Periostin may be considered as an inflammatory marker in periodontal disease. However, further studies are needed to confirm this finding.

Short dental implants in the posterior maxilla: a review of the literature.

The purpose of this study was to perform a literature review of short implants in the posterior maxilla and to assess the influence of different factors on implant success rate. A comprehensive search was conducted to retrieve articles published from 2004 to 2015 using short dental implants with lengths less than 10 mm in the posterior maxilla with at least one year of follow-up. Twenty-four of 253 papers were selected, reviewed, and produced the following results. (1) The initial survival rate of short implants in the posterior maxilla was not related to implant width, surface, or design; however, the cumulative success rate of rough-surface short implants was higher than that of machined-surface implants especially in performance of edentulous dental implants of length <7 mm. (2) While bone augmentation can be used for rehabilitation of the atrophic posterior maxilla, short dental implants may be an alternative approach with fewer biological complications. (3) The increased crown-to-implant (C/I) ratio and occlusal table (OT) values in short dental implants with favorable occlusal loading do not seem to cause peri-implant bone loss. Higher C/I ratio does not produce any negative influence on implant success. (4) Some approaches that decrease the stress in posterior short implants use an implant designed to increase bone-implant contact surface area, providing the patient with a mutually protected or canine guidance occlusion and splinting implants together with no cantilever load. The survival rate of short implants in the posterior edentulous maxilla is high, and applying short implants under strict clinical protocols seems to be a safe and predictable technique.

Effects of nicotine in the presence and absence of vitamin E on morphology, viability and osteogenic gene expression in MG-63 osteoblast-like cells.

BACKGROUND: Evidence shows that oxidative stress induced by nicotine plays an important role in bone loss. Vitamin E with its antioxidative properties may be able to reverse the effects of nicotine on bone. This study aimed to assess the effects of nicotine in the presence and absence of vitamin E on morphology, viability and osteogenic gene expression in MG-63 (osteosarcoma) human osteoblast-like cells. METHODS: We treated the cells with 5 mM nicotine. The viability and morphology of cells were evaluated respectively using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) and crystal violet assays. The effect of nicotine on osteogenic gene expression in MG-63 cells was assessed by real-time reverse-transcription polymerase chain reaction of osteoblast markers, namely, alkaline phosphatase, osteocalcin and bone sialoprotein. RESULTS: The results revealed that survival and proliferation of MG-63 cells were suppressed following exposure to nicotine, and cytoplasm vacuolization occurred in the cells. Nicotine significantly down-regulated the expression of osteogenic marker genes. Such adverse effects on morphology, viability and osteogenic gene expression of MG-63 cells were reversed by vitamin E therapy. CONCLUSIONS: In conclusion, vitamin E supplementation may play a role in proliferation and differentiation of osteoblasts, and vitamin E can be considered as an anabolic agent to treat nicotine-induced bone loss.

The effect of nicotine and cotinine on human gingival fibroblasts attachment to root surfaces.

BACKGROUND: Different compounds of smoking (e.g., nicotine and cotinine) are risk factors for various diseases such as oral cancer and periodontal diseases. Some studies reported the negative effects of nicotine on cell proliferation and differentiation. The present in vitro study assessed the effects of nicotine and cotinine (long-acting metabolite of nicotine) on the attachment and viability of human gingival fibroblast (HGF) cells to tooth root surfaces. METHODS: A total of 70 teeth specimens were placed into 48-well culture plates and covered with HGF cell suspension, in complete Dulbecco's modified Eagle's medium culture medium containing 1 nM, 1 µm, 1 mM, and 5 mM of nicotine and cotinine concentrations. Cellular attachment and viability measured using an MTT assay and a scanning electron microscope were used for cell morphological evaluation. RESULTS: After 24 h, low (nanomolar and micromolar) and high concentrations (millimolar) of nicotine and cotinine caused a significant reduction in the initial cell adhesion in comparison with the control group, but no significant difference was observed between the nicotine and the cotinine groups (p<0.05). Dentally attached cells with low concentrations of nicotine and cotinine proliferated 48 h after exposure, the same as the control group. However, dentally attached cells with high concentrations of nicotine and cotinine (especially 5 mM) did not proliferate 24 h after exposure (p<0.05). CONCLUSIONS: Low concentrations of nicotine and cotinine caused a reduction in the initial cell adhesion. However, no significant adverse effects on the proliferation of attached cells were seen in the longer period. High concentrations of nicotine and cotinine have adverse effects on the cell adhesion and proliferation of HGF cells.

Gingival biotype: a review.

Among the factors that may impede success in dental treatments, gingival biotype is the greatest cause of concern, particularly affecting the outcomes of periodontal therapy, root coverage procedures, and implant placement. Different tissue biotypes respond differently to inflammation and to surgical and restorative treatment; consequently, it is crucial to identify tissue biotype before treatment. Special care must be taken when treatment planning for cases with a thin gingival biotype. This article reviews the characteristics of various gingival biotypes and the many ways to determine them.

Comparison of the acceptability of a new scoring system with Misch's classification for dental implant success determination.

AIMS: The present study aimed at evaluating the acceptability of the Implant Success Index (ISI) in comparison with the conventional classification system. MATERIALS AND METHODS: A comparative questionnaire was designed to evaluate 10 criteria that were reported to be important for acceptance of a new classification system. We asked 20 experts who had at least 5 years of clinical experience in implant dentistry to complete a questionnaire based on a visual analog scale. Data were analyzed by a blinded statistician using a Wilcoxon non-parametric rank test. RESULTS: Measuring all 10 criteria, the acceptability level of ISI was significantly higher than that of the Misch classification (70.90 and 54.90, respectively; P < 0.05). The most significant differences were found in the system's ability to detect early lesions, its lack of overestimation, its quantitative base, and its comprehensiveness. The simplicity and compatibility of the two understudy classification systems were not significantly different. CONCLUSIONS: ISI seems to be a proper scoring system with a high level of acceptability for determining the success rate of dental implants and for selection of procedures used for improving the status of peri-implant tissue.

Bacterial leakage of GuttaFlow-filled root canals compared with Resilon/Epiphany and Gutta-percha/AH26-filled root canals.

The purpose of this study was to assess bacterial apical leakage in root canals obturated with GuttaFlow and compare this with the leakage of root canals obturated with Resilon/Epiphany or Gutta-percha/AH26. A total of 55 single-rooted human teeth were divided randomly into three experimental (n = 15) and two control groups (n = 5). Following a standardised preparation, the teeth were obturated with either GuttaFlow, Resilon/Epiphany or Gutta-percha/AH26. A two-chamber bacterial model using Enterococcus faecalis was employed to assess bacterial apical leakage for a period of 60 days. A Kruskal-Wallis test showed no significant differences between the seal of root canals obturated with GuttaFlow, Resilon/Ephiphany or Gutta-percha/AH26.