A systematic review on regenerative alveolar graft materials in clinical trials: Risk of bias and meta-analysis.

BACKGROUND: Alveolar cleft grafting is a necessary procedure to restore bone defects. Randomized clinical trials (RCTs) are regarded as a golden standard for investigating the efficacy of treatments. Nevertheless, risk of bias (RoB) can still affect the validity of these trials. We aimed to conduct a systemic review of all control trials (CTs) using regenerative materials for alveolar cleft reconstructions to evaluate their RoB and perform a meta-analysis of new bone formation. METHODS: Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (PubMed), EMBASE AND Google Scholar were searched up to October 2020. Thereafter, the articles underwent quality assessment (according to the Jadad scale and the Delphi list) for the evaluation of the RoB. RESULTS: A total of 15 trials met the inclusion criteria, none of which reached a full score. Of these, 20% didn't randomize the trails, 73,33% failed to describe the way of randomization, and none reported the double-blinded criteria. Furthermore, allocation concealment (99.9%), intention to treat (100%), and patient awareness (100%) were inadequately described. The meta-analysis found no significant difference between regenerative materials and iliac crest graft. CONCLUSION: This review showed high RoB in CTs implying quality improvement of CTs is necessary. Meta-analysis showed no significant difference between the regenerative materials and autogenous grafts.

Vertical bone augmentation procedures: basics and techniques in dental implantology.

An appropriate bony situation is essential for dental implant placement and bony support of soft tissues (pink esthetic). Loss of teeth often results in complex horizontal and vertical alveolar ridge defects. They demand advanced bone augmentation techniques for reconstruction. We present the different techniques and materials used in complex bone augmentation. Clinical cases show the application of the methods in the clinical setting. We present current techniques and materials used in complex bone augmentations. Clinical cases show the application of the methods in the clinical setting. Applied techniques include stabilized-guided bone regeneration (GBR), autologous local block augmentation, modified techniques such as Gellrich shell technique including piezosurgery, pelvic bone blocks, complex materials such as graft-derived bone blocks and their unique handling problems. Successful basic principles are reduction of cortical bone healing due to long remodeling time and possible late loss; extended application of materials with interconnecting porous system and particulate material resulting in fast healing analogous to cancellous bone; mechanical stabilization of the augmentation to allow bony healing in vertical defect situations. GBR and autologous bone blocks with minimal cortical thickness and a high volume of particulated material are most favorable techniques.

[Freshwater sponge silicateins: comparison of sequences and exon-intron structure of genes].

Siliceous sponge spicules contain silicateins--proteins taking part in biogenic silica precipitation and determination of the spicule morphological features. The exon-intron structure of four silicatein-alpha isoforms: -alpha1,-alpha2, -alpha3 and -alpha4 from endemic baikalian sponge Lubomirskia baicalensis was studied. For eight sponge species, including both cosmopolitan (Spongilla lacustris, Ephydatia muelleri, E. fluviatilis) and Baikal endemic (L. baicalensis, L. incrustans, Baikalospongia intermedia, B. fungiformis, Sw. papyracea) species, seventeen gene fragment sequences of different silicatein isoforms were determined. It was shown that cosmopolitan and endemic Baikalian sponges differ from each other by gene structure (have different length ofintrons). Among Baikalian sponges silicatein-alpha1 has the most variable intron length, and silicatein-alpha4 is the most conservative. Phylogenetic analysis of amino-acid silicatein sequences allow identify different silicatein isoforms, which authentically differ form four clusters on phylogenetic tree. Phylogenetic analysis of exon-intron sequences gives the possibility to separate different sponge species in the clusters.