Analyses of composition, distribution of cellular and extracellular matrix components, and molecular analysis of mitochondria related genes of bone loss in the presence of inflammatory environment in humans was the aim of the present project. As a human model we chose peri-implantitis. Morphological analyses were performed by means classical histological, immunohistochemical, and SEM (scanning electron miscroscopy) test. Gene expression analysis was performed to evaluate epithelium maturation, collagen fiber production, and genes related to mitochondrial activity. It was found that a well-defined keratinocyte epithelium was present on the top of all specimens; a distinct basal lamina was present, as well as desmosomes and autophagic processes related to the maturation of keratinocytes. Under this epithelium, a full inflammatory cell infiltrate was present for about 60% of the represented by plasma cells. Collagen type I fibers were present mainly in the form of fragmented cord tissue without cells. A different distribution of blood vessels was also present from the apical to the most coronal portion of the specimens. High levels of genes related to oxidative stress were present, as well as the activation of genes related to the loss of ability of osteogenic commitment of Mesenchymal stem cells into osteoblasts. Our study suggests that peri-implantitis lesions exhibit a well defined biological organization not only in terms of inflammatory cells but also on vessel and extracellular matrix components even if no difference in the epithelium is evident, and that the presence of reactive oxygen species (ROS) related to the inflammatory environment influences the correct commitment of Mesenchymal stem cells.
This randomized controlled clinical trial evaluated the effect of mineralized plasmatic matrix (MPM), comprised of synthetic graft and platelet concentrates, on new bone formation and volume stability over time in maxillary sinus lifting (MSL). Unilateral MSL was performed in 20 patients with either beta-tricalcium phosphate (β-TCP) or MPM grafts (10 sinuses each). Six months postsurgery, specimens were obtained with a trephine bur prior to implant placement in 39 cases. Volumetric changes in sinus augmentation were analyzed between 1 week (T-I) and 6 months (T-II) postsurgery. Histomorphometric and histological analyses of biopsy samples revealed mean new bone percentages of 35.40% ± 9.09% and 26.92% ± 7.26% and residual graft particle areas of 23.13% ± 6.16% and 32.25% ± 8.48% in the MPM and β-TCP groups, respectively (p < 0.05). The mean soft-tissue areas in the MPM and β-TCP groups were 41.48% ± 8.41% and 40.83% ± 8.86%, respectively (p > 0.05). Graft reductions between baseline and 6-months postprocedure in the β-TCP and MPM groups were 17.12% ± 13.55% and 14.41% ± 12.87%, respectively, with significant graft volume reduction observed in both groups (p < 0.05) while there is no significant difference between MPM and β-TCP groups (p > 0.05). Thus, MPM, representing growth factors in a fibrin network, increases new bone formation and has acceptable volume stability in MSL procedures
Platelet rich fibrin (PRF) is an autologous biological product which becomes popular day by day and available in a wide variety of fields in medicine. Platelet concentrates which are introduced at the early 90s have evolved over the years. The use such autologous materials have become trendy in recent years to encounter demanding expectations of patients, improve treatment success and maximize patient comfort. Despite its increasing use in dentistry and oral surgery, the most indications and effects are still being discussed. PRF is easily accepted by patients because of its low cost, easy to receive, low donor morbidity, low postoperative complication and infection rate. This biomaterial may be a solution for patients who have strong negative beliefs about the use of allografts and xenografts or who are afraid of complications during the grafting procedure. The objectives of these technologies are to use their synergistic effect to improve the hard and soft tissue regeneration. PRF in oral surgery are used for alveolar bone reconstruction, dental implant surgery, sinus augmentation, socket preservation, osteonecrosis, oroantral fistula closure, struggling with oral ulcers, preventing swelling and edema constitution. This chapter aims to review the clinical applications of platelets in oral surgery and the role of molecular components in tissue healing.
(1) Background: Bone Lamina Technique and Guided Bone Regeneration (GBR) are commonly used for horizontally-deficient maxillary ridge reconstruction, although more detailed evaluation to assess the differences between such techniques is necessitated. (2) Methods: In this retrospective study, patients having a horizontal bone width of ≤4 mm in the maxilla, who were treated with Cortical Strut (CS), were collected to represent the “test group”, and those treated with GBR with no CS involvement represented the “control group”. A 1:1 mixture of autogenous bone (AB) and anorganic bovine bone (ABB) with resorbable collagen membrane was applied to both groups. Volumetric changes between groups were measured with cone-beam computed tomography (CBCT). The primary outcome represented volumetric graft resorption rate whilst the secondary outcomes represented any probable complications and implant insertion torque. (3) Results: A total of 36 patients were included in this study (36 grafted sites; 18 for CS group and 18 for GBR group). Mean bone graft volume reduction in the CS and GBR groups was 8.26 ± 1.60% and 14.36 ± 3.55%, respectively. The GBR group showed significantly more bone resorption than the CS group (p < 0.001). Complications and insertion torque were similar between the groups (p > 0.05). (4) Conclusions: Both CS and GBR techniques for hard-tissue augmentation provided sufficient bone graft mass volume for implant insertion, whereas CS demonstrated lower resorption rate at maxillary augmented sites, compared to GBR.
Background : CBL around implants is a multifactorial process with multiple etiology. Several factors like thickness of the gingiva at the implant site have been identified to affect early in time the amount of CBL. Most of the studies have been generated with implants loaded after more than 2 months following surgery. To the best of our knowledge, there is no experimental or clinical study comparing the effect of the gingiva thickness on early loaded implants. Aim/Hypothesis : To retrospectively evaluate the effect of soft tissue thickness on crestal bone loss of early loaded implants after 1 and 5 years. Materials and Methods : 44 tapered implants with platform switching (C1 ® , MIS) were crestally placed in the posterior mandible and maxilla to rehabilitate edentulous sites; healing followed a 2-stage surgical protocol. The implants were loaded after six to eight weeks. Mesial and distal crestal bone loss (CBL) and soft tissue thickness (STT) were measured on standardized panoramic radiographs. Thin gingiva sites were 21, average thickness was 2.0 ± 0.3 mm; thick gingiva sites were 23, average thickness was 3.0 ± 0.8 mm. Success rate and crestal bone loss were measured after 1 and 5 years. The t-test was used to compare the CBL differences between groups; significance was set at 0.05. Results : No early loaded implant failed at the 1-and 5-year of follow-up; the success rate was 100%. After 1 year, the CBL of the thin and thick gingival groups were 0.96 ± 0.49 and 0.55 ± 0.41 mm, respectively; the difference was statistically significant (P = 0.004). After 5 years, the CBL of the thin and thick gingiva groups increased to 1.12 ± 0.84 and 0.65 ± 0.69 mm, respectively; the difference however was not statistically significant (P = 0.052). Pairwise comparison of CBL between the 1-and 5-year follow-up for the thin and thick gingiva groups showed no statistically significant differences. Conclusions and Clinical Implications : Within the limitations of this study, early loading of C1 implants within 6 to 8 weeks is considered to be safe. After 1 year, CBL was more pronounced at sites with a thin gingiva; at 5 years the difference between the groups was levelled. Between 1 and 5 years, the CBL increased slightly but not in a statistically significant way.
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