Radiographic assessment of maxillary sinus lateral wall thickness in edentulous posterior maxilla

Background and aim: Given the importance of evaluating the maxillary sinus lateral wall thickness (LWT) to avoid complications during surgery, the aim of this study was to examine LWT as well as the effect of residual ridge height (RH), edentulous region, type of edentulism, age and gender on it. Methods: In this cross-sectional study conducted in 2016, 150 samples of the CBCT imaging archives of the Oral and Maxillofacial Radiology Clinic in Babol, Iran, were evaluated retrospectively. In the coronal section, RH and LWT (at 3, 7, 10 and 15 mm from the lowest point of the sinus floor) were measured in NNT software in millimeters. Data were analyzed using the SPSS v22 software through independent-samples t-test, paired-samples t-test and ANOVA. Results: In 150 assessed images, by increasing the wall distance from the floor, the mean sinus lateral wall thickness was increased (p=0.01). There was no relationship between gender and age with the sinus lateral wall thickness (p>0.05). RH showed a significant relationship with LWT so that the higher the RH, the greater the LWT (p<0.05). It was also observed that the mean LWT was 1.31±0.3 mm in the partial edentulism and 0.95±0.26 mm in the complete edentulism (p<0.05). The maximum thickness was found in the first molar and the minimum values were in the second premolar and the second molar. Conclusion: Due to the impact of residual ridge height and type of edentulism on LWT and anatomical variations observed in the maxillary sinus, CBCT assessment is recommended before surgery such as sinus lifting in this are

An in vitro evaluation of novel NHA/zircon plasma coating on 316L stainless steel dental implant

The surface characteristics of an implant that influence the speed and strength of osseointegration include crystal structure and bioactivity. The aim of this study was to evaluate the bioactivity of a novel natural hydroxyapatite/zircon (NHA/zircon) nanobiocomposite coating on 316L stainless steel (SS) dental implants soaking in simulated body fluid. A novel NHA/zircon nanobiocomposite was fabricated with 0 (control), 5, 10, and 15 wt% of zircon in NHA using ball mill for 1 h. The composite mixture was coated on SS implants using a plasma spray method. Scanning electron microscopy (SEM) was used to evaluate surface morphology, and X-ray diffraction (XRD) was used to analyze phase composition and crystallinity (Xc). Further, calcium ion release was measured to evaluate the coated nanobiocomposite samples. The prepared NHA/zircon coating had a nanoscale morphological structure with a mean crystallite size of 30–40 nm in diameter and a bone-like composition, which is similar to that of the biological apatite of a bone. For the prepared NHA powder, high bioactivity was observed owing to the formation of apatite crystals on its surface. Both minimum crystallinity (Xc=41.1%) and maximum bioactivity occurred in the sample containing 10 wt% of zircon because of minimum Xc and maximum biodegradation of the coating sample