Sinus floor elevation with platelet-rich fibrin alone : a clinical retrospective study of 1-7 years

Several sinus floor elevation procedures for implant placement have been introduced. The present study aimed to evaluate the implants placed with Platelet-rich fibrin (PRF) alone in atrophic posterior maxillae and survival rates and the potential factors associated with implant loss. This retrospective study evaluated 71 implants in 34 patients after 1-7 years? follow-up time. Statistical models were used to determine the implant survival and the potential factors associated with loss. Overall, 7 implants were lost, and the cumulative survival rate at 7 years by implant-based and patient-bases analyses were 85.5% and 85.7%, respectively. The mean residual bone height (RBH) was 4.26 mm. The implant survival rate was significantly lower at RBH < 4 mm than RBH ? 4 mm. This retrospective study showed that sinus floor elevation with PRF alone could be applied in cases of lower RBH. However, it should be carefully performed in cases of RBH < 4 mm before surgery

Extracellular inorganic phosphate regulates gibbon ape leukemia virus receptor-2/phosphate transporter mRNA expression in rat bone marrow stromal cells

In mammalian cells, several observations indicate not only that phosphate transport probably regulates local inorganic phosphate (Pi) concentration, but also that Pi affects normal cellular metabolism, which in turn regulates apoptosis and the process of mineralization. To elucidate how extracellular Pi regulates cellular functions of pre-osteoblastic cells, we investigated the expression of type III sodium (Na)-dependent Pi transporters in rat bone marrow stromal cells and ROB-C26 pre-osteoblastic cells. The mRNA expression level of gibbon ape leukemia virus receptor (Glvr)-2 was increased by the addition of Pi in rat bone marrow stromal cells, but not in ROB-C26 or normal rat kidney (NRK) cells. In contrast, the level of Glvr-1 mRNA was not altered by the addition of extracellular Pi in these cells. The induction of Glvr-2 mRNA by Pi was inhibited in the presence of cycloheximide (CHX). Moreover, mitogen-activated protein kinase (MEK) /extracellular-signal-regulated kinase (ERK) pathway inhibitors; U0126 (1.4-diamino-2, 3-dicyano-1, 4-bis [2-amino-phenylthio] butadiene) and PD98059 (2-Amino-3-methoxyflavone) inhibited inducible Glvr-2 mRNA expression, but p38 MEK inhibitor SB203580 [4-(4-fluorophenyl)-2-(4-methyl-sulfinylphenyl)-5-(4pyridyl) imidazole] did not inhibit the induction of Glvr-2 mRNA expression, suggesting that extracellular Pi regulates de novo protein synthesis and MEK/ERK activity in rat bone marrow stromal cells, and through these, induction of Glvr-2 mRNA. Although Pi also induced osteopontin mRNA expression in rat bone marrow stromal cells but not in ROB-C26 and NRK cells, changes in cell viability with the addition of Pi were similar in both cell types. These data indicate that extracellular Pi regulates Glvr-2 mRNA expression, provide insights into possible mechanisms whereby Pi may regulate protein phosphorylation, and suggest a potential role for the Pi transporter in rat bone marrow stromal cells

Rare root canal morphology of maxillary second molars: A report of three cases

Key Clinical Message Endodontists should be aware that some maxillary second molars can have more than three roots. If any unusual anatomical features are detected during dental radiography or endodontic procedures, it is necessary to conduct cone‐beam computed tomography (CBCT) scanning to prevent procedural mishaps. Abstract CBCT can provide three‐dimensional reconstructed images of the root canal system. With the help of CBCT, variations in tooth root number and root canal morphology, such as extra canals, apical ramifications, apical deltas, and lateral canals, can be identified. Knowledge of the variations is very important for the success of endodontic treatment. This report suggests that endodontists must not assume that a MSM has only three tooth roots, which is the most prevalent number

Sinus Augmentation by Platelet-Rich Fibrin Alone: A Report of Two Cases with Histological Examinations

In sinus floor augmentation of an atrophic posterior maxilla, platelet-rich fibrin (PRF) has been used as a graft material. We herein report two cases with histological evaluations of PRF after the surgery. The first case was a 28-year-old female with an atrophic right posterior maxilla who was treated with sinus floor augmentation and simultaneous implant placement using PRF as the sole graft material in our hospital. Twenty-four months after surgery, the implant was unfortunately removed because of occlusal overloading by parafunctional habits. During implant replacement, a tissue sample was obtained from the site of augmentation with PRF and was evaluated histologically. The second case was a 58-year-old man with severe alveolar atrophy of the right maxilla who underwent lateral sinus augmentation using only PRF in a two-stage procedure in our hospital. Samples were obtained at the second-stage surgery and histological examinations were performed. As a result, new bone formation was confirmed histologically in both cases. Our findings show that the use of PRF as a graft material during sinus floor augmentation induces natural bone regeneration