Objectives: Many procedures require the use of bone grafts to replace or recover the volume of bone that has been resorbed. Many configurations of dental implants exist, along with bone autografts, bone allograft, alloplastic bone substitutes and bone xenograft, to recreate physiological occlusion, and aesthetic and masticatory function. We aimed to investigate whether autogenous bone is still the gold standard for treating patients. Methods: We performed an electronic literature search of the PubMed[tm] database using search terms “substitute bone materials”, “bone grafts”, “bone autografts”, “alloplastic bone”, “bone allograft” and “bone xenograft”. We identified between 100 and 200 research papers and reviews, from which the abstract was read to select 70 (excluding all those that did were not dentistry-related). Qualitative assessment was performed on publications that clearly met the following inclusion criteria: recent papers, published in the last 8 years, related to the terms listed above. Results: The individual healing profile of a given bone substitute with respect to osteogenic potential and substitution rate must be considered when selecting adjunctive grafting materials for bone regeneration procedures. Bone replacement materials could be classified into xenografts, or. substances or other natural hydroxyapatite and biocompatible substances. Allograft materials belong to the same species, but do not contain living cells. Alloplastic materials are synthetic materials used instead of real bone. Autograft bone can be obtained from various intraoral and extraoral sites, such as iliac crest, cranial vault, and tibia of the patient. Different case reports reported the use of different bone substitutes. In one study, standardised mandibular defects in mini-pigs were filled with nanocrystalline hydroxyapatite (HA-SiO), deproteinised bovine bone mineral (DBBM), biphasic calcium phosphate (BCP) with a 60/40% HA/β-TCP (tricalcium phosphate) (BCP 60/40) ratio, or particulate autogenous bone for histological and histomorphometric analysis. At 2 and 8 weeks, the percentages of fillers in the test groups were DBBM 35.65%, HA-SiO 34.47%, and BCP 60/40 23.64%. It was significantly higher than autogenous bone and was substituted more quickly, producing more new bone (17.1% ). These findings suggest that the osteogenic potential of HA-SiO and BCP is inferior to that of autogenous bone. However, if a low substitution rate is desired to stabilise volume, as in the aesthetic zone, then HA-SiO and DBBM may be preferable. Conclusion: Despite the increasing number of available bone substitutes in the last years, bone autografts remain the gold standard. They are osteogenic, osteoinductive and osteoconductive, and the newer ones have a regulatory action.

Objectives: The objective of this study was compare the osteogenic differentiation potential and mineralisation of STRO-1-positive selected mesenchymal stem cells derived from human tooth germ (hTGSCs) with a heterogeneous hTGSC population, and to determine whether a minor cell subpopulation is more committed to osteogenic differentiation. Methods: Human TGSCs were isolated from dental follicle and apical papilla tissues of impacted tooth germs of third molars from volunteers aged 13–20 years. Cells were expanded and characterised by flow cytometric analysis with CD34, CD45, CD105, CD90, CD44, CD14 and CD117 antigens. Following surface-antigen profiling, STRO-1 antigen, defining a mesenchymal stem cell subpopulation, was used for cell selection with flourescence-activated cell sorting (FACS). Three cell populations (STRO-1 positive, STRO-1 negative, and unsorted) were tested for their ability to differentiate towards osteoblast-like phenotype in osteogenic medium and standard culture medium. Cultures were analysed for cell proliferation (MTS assay and protein assay) and alkaline phosphotase (ALP) activity on days 1, 4, 7, 14 and 21; calcium deposition and gene expression of runx2, osteocalcin and osteonectin with real-time polymerase chain reaction (RT-PCR) on days 7, 14 and 21. Mineralisation and cell phenotype were further screened with Von Kossa staining and confocal microscopy on days 7, 14 and 21. Statistical analysis was made with SPSS Statistics 22[tm]. Kruskal Wallis and Mann–Whitney U tests were applied and a p value of Results: Flow cytometry analysis of passage 3 (p3) hTGSCs showed positivity for CD44, CD90 and CD105, and negativity for CD14, CD45, CD34 and CD117. A total of 11% of p3 hTGSCs were sorted as STRO-1-positive and 24% as STRO-1-negative. In STRO-1-positive cells, osteogenic groups showed significantly higher calcium content than the controls on days 7, 14 and 21. In STRO-1-negative and unsorted cells, the osteogenic groups showed significantly higher calcium content on days 14 and 21 compared to controls. Calcium deposition was not significantly different in osteogenic cell groups in on days 7, 14 and 21. Calcium content seemed to increase in all cell groups from day 7 to day 21. In osteogenic groups, ALP activity of unsorted cells was significantly higher than that of STRO-1-positive and STRO-1-negative groups on days 7, 14 and 21, suggesting a faster rate of osteogenic differentiation in this group, whereas there was no statistical difference between groups on day 21. Activity of ALP was lowest in all groups on day 7 and increased on days 14 and 21. Osteocalcin was expressed in all groups, with no significant difference between them. Osteonectin was highly and significantly expressed in all osteogenic groups on day 7, which is consistent with the findings for ALP and calcium deposition, suggesting that mineralisation was initiated on day 7. Runx2 was downregulated from day 7 to 14. There were no significant differences in the expression of late and early markers of mineralisation in all osteogenic cell groups. Conclusion: Human TGSCs are a novel stem cell source without ethical issues that can be obtained from routine dental treatments. These results suggest they have a high capacityfor osteogenic differentiation. Selecting groups based on STRO-1 negativity or positivity offers no advantages over unsorted cells, but other osteogenic markers might be allow selection of more sensitive osteogenic subpopulations from hTGSCs.

Objectives: The aim of this study was to evaluate maxillary sinus health in patients who underwent sinus floor augmentation for implant placement after endoscopic sinus surgery (ESS) for the treatment of chronic maxillary sinusitis. Methods: In this series, ESS was performed on four patients with chronic maxillary sinusitis before sinus floor augmentation. A two-stage sinus floor augmentation was performed using deproteinised bovine bone graft and non-cross-linked collagen membrane, 3 months later. Root-form dental implants were placed after 5 months of healing. Cone-beam CT (CBCT) images were taken before ESS, before and after sinus augmentation, and 3 years postoperatively. Sinus membrane thickness and ostium patency were evaluated during the observation period. Marginal bone loss for each dental implant was analysed by CBCT scanning and implant success was evaluated. All patients were rehabilitated with implant-supported fixed restorations. Results: All dental implants were placed in the grafted sinuses and the success rate was 100%. Sinusitis did not recur during the 3-year follow-up period. The ostiomeatal complex was not stenosed after ESS throughout the observation period, however the sinus membranes of two patients were thick and almost filled the sinus cavity before sinus floor augmentation. Corticosteroids were administered for 3 weeks to decrease the membrane thickness. Additive CBCT images confirmed membrane changes in these patients. On completion of medical therapy, sinus floor augmentations could be performed. Conclusion: ESS therapy before sinus augmentation is a reliable and predictable technique for achieving and maintaining the normal physiological environment of the maxillary sinus, after which dental implants can be safely placed in augmented sinus floor sites. CBCT scanning at regular intervals is recommended after ESS treatment for monitoring sinus membrane inflammation and ostium patency.