Al-Rawi NH, et al. Imaging Sci Dent. 2019 Mar;49(1):45-51. https://doi.org/10.5624/isd.2019.49.1.45

Background: Titanium dioxide dental implants have a controversial effect on reactive oxygen species (ROS) production. ROS is necessary for cellular signal transmission and proper metabolism, but also has the ability to cause cell death as well as DNA, RNA, and proteins damage by excessive oxidative stress. This study aimed to systematically review the effect of titanium dioxide dental implant-induced oxidative stress and its role on the osteogenesis-angiogenesis coupling in bone remodeling. Methods: This systematic review was performed conforming to preferred reporting items for systematic review and meta-analysis (PRISMA) model. Four different databases (PubMed, Science Direct, Scopus and Medline databases) as well as manual searching were adopted. Relevant studies from January 2000 till September 2021 were retrieved. Critical Appraisal Skills Programme (CASP) was used to assess the quality of the selected studies. Results: Out of 755 articles, only 14 which met the eligibility criteria were included. Six studies found that titanium dioxide nanotube (TNT) reduced oxidative stress and promoted osteoblastic activity through its effect on Wnt, mitogen-activated protein kinase (MAPK) and forkhead box protein O1 (FoxO1) signaling pathways. On the other hand, three studies confirmed that titanium dioxide nanoparticles (TiO₂NPs) induce oxidative stress, reduce ostegenesis and impair antioxidant defense system as a significant negative correlation was found between decreased SIR3 protein level and increased superoxide (O₂^•-). Moreover, five studies proved that titanium implant alloy enhances the generation of ROS and induces cytotoxicity of osteoblast cells via its effect on NOX pathway. Conclusion: TiO₂NPs stimulate a wide array of oxidative stress related pathways. Scientific evidence are in favor to support the use of TiO₂ nanotube-coated titanium implants to reduce oxidative stress and promote osteogenesis in bone remodeling. To validate the cellular and molecular cross talk in bone remodeling of the present review, well-controlled clinical trials with a large sample size are required.

Objectives. To evaluate the efficacy of bone texture fractal dimension (FD) analysis method in predicting implant stability from intraoral periapical radiographs using two implant protocols. Materials and Methods. A double-blind clinical trial was conducted on 22 subjects who needed dental implants. The participants were randomized into two groups, the control group with standard implant protocol treatment and the intervention group with added low-intensity power ultrasound treatment (LIPUS) besides the standard implant protocol. The FD values of bone density were carried out on the mesial and distal sides of the implant on digital intraoral radiographs using the box-counting method. Both resonance frequency (RF) and fractal dimension (FD) were assessed in three time intervals: after surgery and before and after loading. Results. FD on both the mesial and distal sides serve as very good-to-excellent tests with high validity (ROC area exceeding 0.8) in predicting high implant stability (ISQ ≥ 70). The mesial side measurements were consistently better than the distal side among the intervention groups. The optimum cutoff value for the FD-mesial side that predicts a highly stable implant (ISQ ≥ 70) is ≥1.505. At this optimum cutoff value, the mesial side FD is associated with a perfect sensitivity (100%) and fairly high specificity (86.5%). Conclusion. The FD analysis could be recommended as an adjunctive quantitative method in prediction of the implant stability with very high sensitivity and specificity. This trial is registered with ISRCTN72648040.

Application of cellulose-based hydrogels in dentistry has gained significant attention. They are emerging as novel biomaterials in the field of tissue engineering, regeneration, and drug delivery in dentistry. The objective of this scoping review is to highlight and summarize recent developments of cellulose-based hydrogels in their designs, reported applications, and laboratory functions. Methods: Between the periods of November 2014 and November 2024 (searches completed and datasets locked on 30th Nov 2024), the comprehensive electronic database search was performed in PubMed, Science Direct, Scopus, and MyEBSCO. All the studies that are related to cellulose-based and dentistry were included in this review. This review followed the PRISMA-ScR guidelines for the Preferred Reporting Items for Systematic Reviews and Meta-analysis Extension for Scoping Reviews. Results: Out of 518 entries found, 13 studies were qualified for inclusion. When comparative analysis of cellulose-based hydrogel-related studies was performed, most of the included studies were conducted in vitro, and they highlighted significant advancements in their functionality, their inert properties such as mechanical adaptability, design, bioactivity, biodegradability, and clinical potential. Conclusions: Cellulose-based hydrogels show great potential in regenerative dentistry, providing a biomimetic platform for tissue regeneration and drug delivery. Addressing present challenges and exploring pathways towards clinical translation will be critical to know their potential in the future. This review critically evaluates the strengths and weaknesses that are used in the current studies and thus, it provides a resource for future research directions for innovations in the field of regenerative dentistry and tissue engineering.

To assess the effect of LIPUS on marginal bone regeneration during insertion and following loading using CBCT scan imaging, a trial of RCT of 22 subjects needing dental implant was conducted. The participants were randomly allocated into 2 groups; both groups underwent similar two-stage implant surgery of one maxillary dental implant. The control group (n = 11) of the implant site was allowed to heal in a conventional way, while the intervention group (n = 11) was subjected to LIPUS therapy at the implant site (twice a week, 20-minute duration, from week 2 after stage I implant surgery and continued for 10 weeks). Similar ultrasound protocol was repeated 2 weeks after crown installation and again continued for another 10 weeks. The assessment of marginal bone loss around dental implants was carried out at three different views (coronal, sagittal, and axial) of the implant site immediately after surgery, 3 and 6 months later. Statistical analysis of ANOVA within and between two-group analysis that was applied followed by pairwise comparison with confidence interval adjustment showed that there is a significant difference among the groups (p < 0.05). The CBCT imaging (coronal view) values suggested that bucccal bone regeneration around the dental implant has significantly increased during the early osseointegration period in the LIPUS-treated subjects than in the control group. LIPUS enhances bone formation in particular buccal bone plate around the dental implant as confirmed by the coronal view.