Search

Statins have demonstrated positive results in alveolar repair after induced osteoporosis in humans and rats. This study aimed to evaluate the osteogenic potential of rosuvastatin (RSV) solution associated with collagen sponge in post-extraction rat alveoli. An experimental study was carried out at the Fluminense Federal University in 30 Wistar rats (female) randomly distributed into three experimental groups: group I—dental sockets filled with a blood clot (CS); group II—dental sockets filled with collagen sponge (EC); and group III—collagen sponge associated with RSV. Slides stained with hematoxylin and eosin (HE) were used for histomorphometric analysis to evaluate newly formed bone, connective tissue, and biomaterial in the respective groups, comparing them over different periods (7 and 42 days). The Shapiro–Wilk test was used to evaluate the same experimental period, and the Mann–Whitney test was used to compare the different periods between the groups. At 7 days, the clot group showed greater new bone formation (median 23.27; IQR 10.62–4.74) than the sponge group (median 2.25; IQR 3.42–1.53) and RSV group (median 0; IQR 0–0; p = 0.03), respectively. At 42 days, the clot group (median 63.90; IQR 7.54–3.73) showed better results regarding newly formed bone compared to the RSV group (median 26.33; IQR 4.78–2.24; p = 0.003). The present study demonstrated no advantages in the use of RSV in relation to the control group and no statistical difference between groups II and III.

A midpalatal suture contention after rapid maxillary expansion (RME) is a major orthodontic challenge. The objective of this study is to evaluate the effect of systemic simvastatin on suture bone remodeling after disjunction. For that, 15 Wistar rats were used. In 10, orthodontic appliances were installed and activated for 5 days for RME. These animals were randomly divided into two groups: control (CT, n = 5) and simvastatin (SVT, n = 5). Also, animals without intervention (HG, n = 5) were used. In the SVT and CT groups, 5 mg/kg of simvastatin and distilled water were administered by gavage, respectively, for 20 consecutive days. Then, the animals were euthanized and scanned in micro-computed tomography (µCT). The images were analyzed through pixel linear measurement at four different points (P1, P2, P3 and P4), in the intra-incisor distance (DI) and in the suture distance (SD). Microtomographic parameters, such as cortical bone area (Ct.Ar), cortical area fraction (Ct.Ar/Tt.Ar), and cortical thickness (Ct.Th), were obtained. Also, bone volume fraction (BV/TV) and empty space (EV) were extracted. Then, histological slides were prepared for descriptive and histomorphometric analysis. There was a statistically significant difference in the linear measurements, microtomographic parameters, and histomorphometric results between the experimental groups. In conclusion, simvastatin demonstrated an osteoinductive and antiresorptive effect in the palatine suture region after RME.

Bone tissue engineering seeks biomaterials that enable cell migration, angiogenesis, matrix deposition, and tissue regeneration. Blood concentrates like platelet-rich fibrin (L-PRF) offer a cost-effective source of cells and growth factors to enhance healing. The present study aimed to evaluate heated serum albumin with liquid PRF (Alb-PRF) and L-PRF clinically and biochemically after placement in dental sockets following mandibular third molar extraction. In a controlled, split-mouth study involving 10 volunteers, 20 extracted molars were treated with either Alb-PRF or L-PRF. Post-extraction, pain, trismus, infection presence, and swelling were measured. The concentrations of different analytes in the surgical sites were also examined. The data were statistically analyzed, with significance defined at p < 0.05 (t-test). No significant difference was noted between the groups for pain and trismus, but Alb-PRF showed a significant reduction in swelling on day seven. The Alb-PRF group showed lower levels of pro-inflammatory cytokines (GM-CSF, IL-1b, IL-6, IFNy, IL-8, IL-15, RANTES, and MIP-1a) after seven days, with only higher expressions of MIP-1b, IL-1b, and MCP-1 found in the L-PRF group. Differences were observed in the release of analytes between L-PRF and Alb-PRF, with Alb-PRF significantly reducing edema after seven days. Alb-PRF reduced edema, while L-PRF increased inflammatory cytokines. When compared to L-PRF, Alb-PRF reduced edema and the release of inflammatory cytokines, suggesting promising effects in socket healing while underscoring the role of growth factors and cytokines in potential applications of blood concentrates.

Background and objectives: Although it is very uncommon, medication-induced osteonecrosis of the jaw (also known as MRONJ) can have serious consequences. Traditionally, this adverse event has been recognised in patients who were treated with bisphosphonate (BP) drugs. Nevertheless, in recent years, it has been established that individuals having treatment with various types of medications, such as a receptor activator of nuclear factor kappa-Β ligand inhibitor (denosumab) and antiangiogenic agents, have had the same issue. The purpose of this research is to determine if the application of human amniotic membrane (hAM) may be used as a therapy for MRONJ. Material and Methods: A multi-source database (MEDLINE, EMBASE, AMED, and CENTRAL) systematic search was performed. The major objective of this study is to obtain an understanding of the efficacy of hAM when it is employed as a treatment modality for MRONJ. The protocol of this review was registered in the INPLASY register under the number NPLASY202330010. Results: The authors were able to include a total of five studies for the quality analysis, whereas for the quantity evaluation, only four studies were eligible. A total of 91 patients were considered for the investigation. After treatment with human amniotic membrane (hAM), a recurrence of osteonecrosis was observed in n = 6 cases (8.8%). The combined efficacy of surgical therapy and the use of hAM resulted in an overall success rate of 91.2%. Intraoperative complications were only documented in one article, and they were mostly caused by the positioning of the hAM, which led to wound breakdown at the surgical site. Conclusions: Based on the small amount of data and low-quality research included in this study, using human amniotic membranes to treat MRONJ might represent a feasible option. Nevertheless, further studies with a wider patient population are required to understand the long-term impacts.

Medication-related osteonecrosis of the jaw (MRONJ) is considered as a severe adverse side effect of specific drugs such as anti-resorptive and anti-angiogenic medications. Evidence suggests that MRONJ is linked to invasive dental procedures, mainly dentoalveolar surgery. Several preventive strategies to minimize the risk of developing MRONJ have been investigated. However, no investigation has been attempted to evaluate the therapeutic effect of local drug-delivery technology as a preventive strategy protocol. The aim of this study is to evaluate the efficacy of hydroxyapatite-containing doxycycline (HADOX) in rats with high-risk MRONJ development. All the rats used in this study were divided into seven groups. Six groups of rats out of seven were exposed to two different doses of antiresorptive drug therapy for four weeks before undergoing an upper incisor extraction. After 28 days, all the animals were euthanized, and the bone blocks were processed for histological and histomorphometrical evaluation. The histomorphometric analysis confirmed that newly formed bone (NFB) was present in all groups, with significant differences. NFB in the HADOX group treated with zoledronic acid at 4% showed (28.38; C.I. 22.29–34.48), which represents a significant increase compared to HA (15.69; C.I. 4.89–26.48) (p = 0.02). A similar pattern was observed in the HADOX group treated with zoledronic acid 8% ZA treatment (p = 0.001). Conclusions: HADOX did not inhibit any bone repair and reduced early inflammatory response. Hence, HADOX could promote bone healing in patients undergoing antiresorptive drug therapy.

Background: Antiresorptive and antiangiogenic medications can cause a serious adverse effect known as medication-related osteonecrosis of the jaw (MRONJ). In recent years, a new trend of research has emerged emphasizing the potential relation of MRONJ and genetic predisposition. Current evidence-based science of this adverse reaction is associated with poorly performed studies. Additionally, MRONJ research has recently observed a new trend of studies orientated towards the misuse of reviews. This quality meta-review intends to summarize the results of all systematic reviews and meta-analyses that have been published on MRONJ in relation to genetic and pharmacogenomics risk factors. Methods: The research study protocol was registered into the database of the International Network for the Registration of Systematic Reviews and Meta-Analyses (INPLASY) INPLASY202230002. A comprehensive search across several databases (PubMed, EMBASE, MEDLINE, and CINAHL) was conducted to locate multi-language papers published between January 2003 and November 2022. Data were collected from relevant research studies and appraised in accordance with the precise outcomes described in this evaluation. Results: Only five systematic reviews and meta-analyses were analysed in this meta-review. All the reviews included in this research presented qualities mistakes and shortcomings. Two quality assessment tools (Confidence in Evidence from Reviews of Qualitative research (CERQual) and Assessment of Multiple Systematic Reviews 2 (AMSTAR-2)) were used to evaluate each study included in this research. Conclusions: The data evaluated by this meta-review confirmed the poor-quality secondary research underpinning the genetic/pharmacogenomics aspect of MRONJ. Moreover, this study highlighted the many flaws of the current published systematic and meta-analysis studies published so far.

Background: Bioceramic nanometer coatings have been regarded as potential substitutes for plasma-sprayed hydroxyapatite coatings, and the association with bone morphogenetic protein (BMP) is an attempt to achieve faster osseointegration to hasten oral rehabilitation. Objective: This study aimed to investigate the effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) on the osseointegration of titanium implants coated with a thin film surface of hydroxyapatite (HA). Methods: Two implants (n = 24) were placed in each white New Zealand rabbits’ femur (n = 6). Implants were placed in the right femur after standard instrumentation (A and B) and in the left femur after an over-instrumentation (C and D), preventing bone-implant contact. The distal implants were installed associated with rhBMP-7 (groups B [regular instrumentation] and D [over-instrumentation]) and, also, in the absence of without BMP (control groups A [regular instrumentation] and C [over-instrumentation]). After 4 weeks, the animals were euthanized. The bone blocks containing the implants were embedded in methyl methacrylate and sectioned parallel to the long axis of the implant, which were analyzed by image segmentation. The data were analyzed using a nonparametric statistical method. Results: We observed that Group A had a mean bone formation of 35.6% compared to Group B, which had 48.6% (p > 0.05). Moreover, this group showed 28.3% of connective tissue compared to Group A, with 39.3%. In the over-instrumented groups, rhBMP-7 (Group D) showed an enhanced and significant increase in bone formation when compared with the group without rhBMP-7 (Group C). Conclusion: We concluded that the association of rhBMP-7 to thin nanostructure HA-coated implants promoted greater new bone area than the same implants in the absence of rhBMP-7, mainly in cases of over-instrumented implant sites.

Background: The degree of biodegradation and the inflammatory response of membranes employed for guided bone regeneration directly impact the outcome of this technique. This study aimed to evaluate four different experimental versions of Poly (L-lactate-co-Trimethylene Carbonate) (PTMC) + Poly (L-lactate-co-glycolate) (PLGA) membranes, implanted in mouse subcutaneous tissue, compared to a commercially available membrane and a Sham group. Methods: Sixty Balb-C mice were randomly divided into six experimental groups and subdivided into 1, 3, 6 and 12 weeks (n = 5 groups/period). The membranes (1 cm2) were implanted in the subcutaneous back tissue of the animals. The samples were obtained for descriptive and semiquantitative histological evaluation (ISO 10993-6). Results: G1 and G4 allowed tissue adhesion and the permeation of inflammatory cells over time and showed greater phagocytic activity and permeability. G2 and G3 detached from the tissue in one and three weeks; however, in the more extended periods, they presented a rectilinear and homogeneous aspect and were not absorbed. G2 had a major inflammatory reaction. G5 was almost completely absorbed after 12 weeks. Conclusions: The membranes are considered biocompatible. G5 showed a higher degree of biosorption, followed by G1 and G4. G2 and G3 are considered non-absorbable in the studied periods.

Objectives: Medication-related osteonecrosis of the jaw (MRONJ) is rare. It is a serious adverse effect of certain drugs, of which bisphosphonates (BPs) are the most widely known. The aim of this systematic review was to analyze all published evidence for the reported adverse outcomes as a result of orthodontic treatment in patients undergoing antiresorptive therapy. Data: All types of studies involving patients undergoing orthodontic treatment and treated with antiresorptive drugs were considered. A meta-analysis was not conducted due to the high amount of variability and heterogeneity in the reporting and presentation of data among the studies meeting the inclusion criteria. Sources: A systematic search was performed using 4 databases (PubMed, MEDLINE, EMBASE and CINAHL). Study selection: Seven studies matched the inclusion criteria for this review, reporting a total of 29 patients. MRONJ was only reported in 1 patient. The adverse outcomes following orthodontic treatment included difficulty achieving root parallelism (n = 4), difficulty achieving complete space closure (n = 3), exaggerated tooth mobility post-debond (n = 2), increased duration of orthodontic treatment beyond expected completion (n = 1), sclerotic alveolar bone changes seen on post-op radiographic images (n = 2), and an increased amount of root resorption (n = 1). Conclusions: The high amount of heterogeneity and limited evidence precluded a valid interpretation and analysis of the results through pooling of data. Additional data with sufficient quality, a reduction of bias, and a greater prospective cohort of patients is crucial to assess adverse effects, mechanisms of action, and associated risk factors in at-risk patients. Clinical significance: Based on the limited evidence available in the literature, it is unclear whether orthodontic treatment alone can precipitate MRONJ. However, antiresorptive drug therapy may be associated with a sub-optimal treatment outcome.

Background: Osteonecrosis of the jaw (ONJ) is a condition affecting patients exposed to medications used to treat benign and malignant conditions of bone tissue. Many studies have highlighted that ONJ is a severe condition, which is very challenging to manage, especially in individuals with oncologic disease. The aim of this umbrella review is to analyze all available interventional and non-interventional systematic reviews published on medication-related osteonecrosis of the jaw (MRONJ) and summarize this evidence. Material and methods: A multi-database search (PubMed, MEDLINE, EMBASE and CINAHL) was performed to identify related multi-language papers published from January 2003 until June 2021. An additional manual search was also performed in systematic review registries (PROSPERO, INPLASY, JBI and OFS) to identify possible missing reviews. Data were extracted from relevant papers and analyzed according to the outcomes selected in this review. Results: The search generated 25 systematic reviews eligible for the analysis. The total number of patients included in the analysis was 80,840. Of the reviews, 64% (n = 16) were non-interventional and 36% (n = 9) were interventional. Study designs included case series 20.50% (n = 140), retrospective cohort studies 12.30% (n = 84) and case reports 12.20% (n = 83). It was unclear what study design was used for 277 studies included in the 25 systematic reviews. Conclusions: The data reviewed confirmed that the knowledge underpinning MRONJ in the last 20 years is still based on weak evidence. This umbrella review highlighted a widespread low-level quality of studies and many poorly designed reviews.

This systematic review (SR) aimed to evaluate implant survival rate, marginal bone loss (MBL), and biological/prosthetic complications of extra-short 4 mm dental implants. An electronic search without language or date restrictions was performed in five databases and in gray literature for articles published until August 2020. Prospective cohort studies and randomized clinical trials (RCTs) that evaluated the clinical performance of extra-short 4 mm dental implants were included. Studies were independently assessed for risk of bias using the Cochrane Collaboration’s tool. The protocol of this SR was registered in the PROSPERO database under number CRD42019139709. Four studies were included in the present SR. There was no significant difference in implant survival rate (p = 0.75) between extra-short 4 mm and long implants. After 12 months of function, the extra-short implants had a significantly (p = 0.003) lower marginal bone loss (MBL) rate when compared to long implants. Extra-short implants had a lower number of biological and prosthetic complications when compared to long implants. After 12 months of follow-up, extra-short 4 mm dental implants placed in the mandible exhibit satisfactory clinical outcomes concerning implant survival rate and MBL when compared to longer implants, with a low number of biological and prosthetic complications. A higher number of RCTs with longer follow-up is necessary for the future.

Medication related osteonecrosis of the jaw (MRONJ) is a severe condition affecting the jaws of patients exposed to specific drugs, and is primarily described in patients receiving bisphosphonate (BP) therapy. However, more recently it has been observed in patients taking other medications, such as the RANK ligand inhibitor (denosumab) and antiangiogenic drugs. It has been proposed that the existence of other concomitant medical conditions may increase the incidence of MRONJ. The primary aim of this research was to analyze all available evidence and evaluate the reported outcomes of osteonecrosis of the jaws (ONJ) due to antiresorptive drugs in immunosuppressed patients. A multi-database (PubMed, MEDLINE, EMBASE and CINAHL) systematic search was performed. The search generated twenty-seven studies eligible for the analysis. The total number of patients included in the analysis was two hundred and six. All patients were deemed to have some form of immunosuppression, with some patients having more than one disorder contributing to their immunosuppression. Within this cohort the commonest trigger for MRONJ was a dental extraction (n=197). MRONJ complications and recurrence after treatment was sparsely reported in the literature, however a total of fourteen cases were observed. The data reviewed have confirmed that an invasive procedure is the commonest trigger of MRONJ with relatively high frequency of post-operative complications or recurrence following management. However, due to low-quality research available in the literature it is difficult to draw a definitive conclusion on the outcomes analysed in this systematic review.

Many biomaterials are used for Bone Morphogenetic Proteins (BMPs) delivery in bone tissue engineering. The BMP carrier system’s primary function is to hold these growth factors at the wound’s site for a prolonged time and provide initial support for cells to attach and elaborate the extracellular matrix for bone regeneration. This study aimed to evaluate the nanostructured carbonated hydroxyapatite microspheres (nCHA) as an rhBMP-2 carrier on rats calvaria. A total of fifteen male Wistar rats were randomly divided into three groups (n = 5): clot (control group), rhBMP-2 associated with collagen membrane (COL/rhBMP-2) or associated with the microspheres (nCHA/rhBMP-2). After 45 days, the calvaria defect samples were evaluated through histological, histomorphometric, and SR-µCT analyses to investigate new-formed bone and connective tissue volume densities. The descriptive histological analysis showed that nCHA/rhBMP-2 improved bone formation compared to other groups. These results were confirmed by histomorphometric and SR-µCT analysis that showed substantially defect area filling with a higher percentage of newly formed (36.24 ± 6.68) bone than those with the COL/rhBMP-2 (0.42 ± 0.40) and Clot (3.84 ± 4.57) (p < 0.05). The results showed that nCHA is an effective carrier for rhBMP-2 encouraging bone healing and an efficient alternative to collagen membrane for rhBMP-2 delivery.

This overview aimed to evaluate the methods, quality, and outcomes of systematic reviews (SRs) conducted to investigate the effects of platelet-rich fibrin (PRF) in dental sockets on promoting bone regeneration and soft tissue healing and diminishing the incidence of pain, swelling, trismus, and alveolar osteitis after tooth extraction. An electronic search without date or language restriction was done in PubMed/MEDLINE, Cochrane, and Web of Science until March 2020. Eligibility criteria included SRs that assessed the effect of PRF for human alveolar socket preservation. The quality assessment of the included studies was performed using AMSTAR 2 guidelines. The protocol of this overview was recorded in PROSPERO under the number CRD42018089617. The search and selection process yielded 13 studies published between 2011 and 2018. The analysis of the studies showed inconclusive data for the effect of the PRF and the dimensional changes. There is no definitive evidence for the impact of using PRF alone on bone regeneration in post-extraction sockets. The use of PRF improves soft tissue healing and reduces pain, bleeding, and osteitis in post-extraction sockets.

ABSTRACT Objective: This study aimed to evaluate bone repair in rat dental sockets after implanting nanostructured carbonated hydroxyapatite/sodium alginate (CHA) and nanostructured carbonated hydroxyapatite/sodium alginate containing 5% strontium microspheres (SrCHA) as bone substitute materials. Methods: Twenty male Wistar rats were randomly divided into two experimental groups: CHA and SrCHA (n=5/period/group). After one and 6 weeks of extraction of the right maxillary central incisor and biomaterial implantation, 5 μm bone blocks were obtained for histomorphometric evaluation. The parameters evaluated were remaining biomaterial, loose connective tissue and newly formed bone in a standard area. Statistical analysis was performed by Mann-Withney and and Wilcoxon tests at 95% level of significance. Results: The histomorphometric results showed that the microspheres showed similar fragmentation and bio-absorbation (p>0.05). We observed the formation of new bones in both groups during the same experimental periods; however, the new bone formation differed significantly between the weeks 1 and 6 (p=0.0039) in both groups. Conclusion: The CHA and SrCHA biomaterials were biocompatible, osteoconductive and bioabsorbable, indicating their great potential for clinical use as bone substitutes.

Objective This in vivo study, aimed to biomechanically, histomorphometrically and histologically evaluate an implant surface coated with nanostructured hydroxyapatite using the wet chemical process (biomimetic deposition of calcium phosphate coating) when compared to a dual acid-etching surface. Material and methods Ten sheep (2–4 years old) received 20 implants, 10 with nanostructured hydroxyapatite coating (HAnano), and 10 with dual acid-etching surface (DAA). The surfaces were characterized with scanning electron microscopy and energy dispersive spectroscopy; insertion torque values and resonance frequency analysis were measured to evaluate the primary stability of the implants. Bone-implant contact (BIC) and bone area fraction occupancy (BAFo) were evaluated 14 and 28 days after implant installation. Results The HAnano and DAA groups showed no significant difference in insertion torque and resonance frequency analysis. The BIC and BAFo values increased significantly (pConclusion The results suggest that the HAnano surface favors bone formation when compared to the DAA surface after 28 days in low-density bone in sheep.

Abstract Primary implant stability is a prerequisite for successful implant osseointegration. The osseodensification technique (OD) is a non-subtractive drilling technique that preserves the bone tissue, increases osteotomy wall density, and improves the primary stability. This study aimed to investigate the hypothesis that OD, through a wider osteotomy, produces healing chambers (HCs) at the implant-bone interface without impacting low-density bone primary stability. Twenty implants (3.5 × 10 mm) with a nanohydroxyapatite (nHA) surface were inserted in the ilium of ten sheep. Implant beds were prepared as follows: (i) 2.7-mm-wide using subtractive conventional drilling (SCD) technique (n = 10); (ii) 3.8-mm-wide using an OD bur system (n = 10). The sheep were randomized to two groups, with samples collected at either 14-(n = 5) or 28-days (n = 5) post-surgery and processed for histological and histomorphometric evaluation of bone-implant contact (BIC) and bone area fraction occupancy (BAFO). No significant group differences were found with respect to final insertion torque and implant stability quotient (p > 0.050). BIC values were higher for SCD after 14 and 28 days (p 0.050). It was possible to conclude that the OD technique allowed a wider implant bed preparation without prejudice on primary stability and bone remodeling.

Background and objectives: Calcium phosphates have been widely used as bone substitutes, but their properties are limited to osteoconduction. The association of calcium phosphates with osteoinductive bioactive molecules has been used as a strategy in regenerative medicine. Melatonin has been studied due to its cell protection and antioxidant functions, reducing osteoclastic activity and stimulating newly formed bone. This study aimed to evaluate the effect of topical application of melatonin associated with nanostructured carbonated hydroxyapatite microspheres in the alveolar bone repair of Wistar rats through histological and histomorphometric analysis. Materials and Methods: Thirty female Wistar rats (300 g) were used, divided randomly into three experimental groups (n = 10), G1: nanostructured carbonated hydroxyapatite microspheres associated with melatonin gel (CHA-M); G2: nanostructured carbonated hydroxyapatite (CHA); G3: blood clot (without alveolar filling). The animals were euthanized after 7 and 42 days of the postoperative period and processed for histological and histomorphometric evaluation. Kruskal–Wallis and Dunn’s post-test were applied to investigate statistical differences between the groups at the same time point for new bone and connective tissue variables. Mann–Whitney was used to assess statistical differences between different time points and in the biomaterial variable. Results: Results showed a greater volume of residual biomaterial in the CHA-M than the CHA group (p = 0.007), and there were no significant differences in terms of newly formed bone and connective tissue between CHA and CHA-M after 42 days. Conclusions: This study concluded that both biomaterials improved alveolar bone repair from 7 to 42 days after surgery, and the association of CHA with melatonin gel reduced the biomaterial’s biodegradation at the implanted site but did not improve the alveolar bone repair.

Sticky bone, a growth factor-enriched bone graft matrix, is a promising autologous material for bone tissue regeneration. However, its production is strongly dependent on manual handling steps. In this sense, a new device was developed to simplify the confection of the sticky bone, named Sticky Bone Preparation Device (SBPD®). The purpose of this pilot study was to investigate the suitability of the SBPD® to prepare biomaterials for bone regeneration with autologous platelet concentrates. The SBPD® allows the blending of particulate samples from synthetic, xenograft, or autogenous bone with autologous platelet concentrates, making it easy to use and avoiding the need of further manipulations for the combination of the materials. The protocol for the preparation of sticky bone samples using the SBPD® is described, and the resulting product is compared with hand-mixed SB preparations regarding in vitro parameters such as cell content and the ability to release growth factors and cytokines relevant to tissue regeneration. The entrapped cell content was estimated, and the ability to release biological mediators was assessed after 7 days of incubation in culture medium. Both preparations increased the leukocyte and platelet concentrations compared to whole-blood samples (p < 0.05), without significant differences between SB and SBPD®. SBPD® samples released several growth factors, including VEGF, FGFb, and PDGF, at concentrations physiologically equivalent to those released by SB preparations. Therefore, the use of SBPD® results in a similar product to the standard protocol, but with more straightforward and shorter preparation times and less manipulation. These preliminary results suggest this device as a suitable alternative for combining bone substitute materials with platelet concentrates for bone tissue regeneration.

This systematic review aimed to review the literature on the coronectomy technique and evaluate the incidence of success and complications as a surgical approach for inferior third molars. Online databases were searched for data on the frequency of inferior alveolar nerve damage, lingual nerve damage, root migration, pain, infection, dry socket, and extraction of the remaining root, and data on the necessity of reintervention were also extracted. Randomized clinical trials, controlled clinical trials, prospective cohort studies, and prospective and retrospective studies with or without the control group were intercepted. This systematic review was registered in PROSPERO (CDR 42020135485). Sixteen papers analyzed 2176 coronectomies in total, and only five of them were judged as appropriate according to methodological quality assessment. The incidence of inferior alveolar nerve injury was documented in 0.59% of the procedures, lingual nerve injury in 0.22%, infection 3.95%, dry socket 1.12%, extraction of the root 5.28%, and reintervention 1.13%. The pain was the most reported, in 22.04% of the population. This study provides an overview of the clinical success and complications of coronectomy, and their prevalence. A coronectomy may be considered a low-risk procedure and an option for treatment to avoid potential damage to nervous structures. However, patients should still undergo a full screening and evaluation of postsurgical procedures.

This study assessed the effects of leukocyte-platelet-rich fibrin (L–PRF) on soft tissue healing and the correlation with the local concentration of growth factors (GF) and cytokines in the dental socket of lower third molars. Forty lower-third molars (20 participants) were included in this randomized, double-blinded, split-mouth study. After extractions, randomized sides received alveolar filling with L–PRF on one side and a natural blood clot on the other side. The pain was assessed for up to seven days and soft tissue healing (Landry index) for 14 days post-extraction. Swabs were collected from the surgical sites for GF and cytokine assessment by flow luminometry. Participants reported lower postoperative pain on the sides grafted with L–PRF, which also presented increased tissue healing scores (p < 0.05). There were increased levels of all GFs and several cytokines at the L–PRF site at day one, while vascular endothelial growth factor (VEGF), IL–10, and IL1–RA remained higher throughout for seven days (p < 0.05). VEGF concentration at L–PRF sites correlated positively with the participants’ blood platelet content (ρ = 0.769). PDGF correlated negatively with pain experience on days 2 and 3, and positively with soft tissue healing scores, while FGFb presented a weak correlation with a reduction of pain on day 3. The use of L–PRF improves the soft tissue healing process and decreases postoperative pain after the third molar extractions, which correlates with an increase in the local concentration of growth factors such as PDGF and FGFb.

The present study aimed to compare the stability of dental implants placed in low-quality bone prepared for the healing chamber with osseodensification technique and a standard undersized drilling. Sixteen subjects presenting D3 or D4 bone density according to Misch’s classification were randomly distributed to receive dental implants following either osseodensification (G1: n = 29) or standard undersized drilling (G2: n = 26) preparation techniques. Implant insertion torque (IT) and implant stability quotient (ISQ) were measured immediately after implant placement. Implant survival and secondary stability (ISQ) were evaluated after six months. The G1 group showed higher IT (39.0 ± 6.4 Ncm) than G2 (32.0 ± 3.4 Ncm) (p < 0.001). ISQ values were similar (p > 0.05) at the implant insertion (67.1 ± 3.2 and 65.5 ± 2.7 for G1 and G2, respectively). After six months healing, implant survival was equally comparable in both groups (p > 0.05), and ISQ values were higher than those of implant insertion (p < 0.001) but similar (p > 0.05) for both groups (74.0 ± 3.6 and 73.3 ± 3.2 for G1 and G2, respectively). Within the limitations of this study, the present RCT demonstrated that a wider surgical bed prepared by osseodensification instrumentation allowed for the bone healing-chamber concept in low-quality bone without any reduction in implant stability and success rate.

Mechanical barriers prevent the invasion of the surrounding soft tissues within the bone defects. This concept is known as Guided Bone Regeneration (GBR). The knowledge about the local tissue reaction and the time of degradation of absorbable membranes favors the correct clinical indication. This study aimed to evaluate the biocompatibility and biodegradation of a bovine collagen membrane (Lyostypt®, São Gonçalo, Brazil) and compare it to a porcine collagen membrane (Bio-Gide®) implanted in the subcutaneous tissue of mice, following ISO 10993-6:2016. Thirty Balb-C mice were randomly divided into three experimental groups, LT (Lyostypt®), BG (Bio-Gide®), and Sham (without implantation), and subdivided according to the experimental periods (7, 21, and 63 days). The BG was considered non-irritant at seven days and slight and moderate irritant at 21 and 63 days, respectively. The LT presented a small irritant reaction at seven days, a mild reaction after 21, and a reduction in the inflammatory response at 63 days. The biodegradation of the LT occurred more rapidly compared to the BG after 63 days. This study concluded that both membranes were considered biocompatible since their tissue reactions were compatible with the physiological inflammatory process; however, the Bio-Gide® was less degraded during the experimental periods, favoring the guided bone regeneration process.

ABSTRACT Objective: Based on a literature review and on our own experience, this study proposes sheep as an experimental model to evaluate the bioactive capacity of bone substitute biomaterials, dental implant systems and orthopedics devices. The literature review covered relevant databases available on the Internet from 1990 until to date, and was supplemented by our own experience. Methods: For its resemblance in size and weight to humans, sheep are quite suitable for use as an experimental model. However, information about their utility as an experimental model is limited. The different stages involving sheep experiments were discussed, including the care during breeding and maintenance of the animals obtaining specimens for laboratory processing, and highlighting the unnecessary euthanasia of animals at the end of study, in accordance to the guidelines of the 3Rs Program. Results: All experiments have been completed without any complications regarding the animals and allowed us to evaluate hypotheses and explain their mechanisms. Conclusion: The sheep is an excellent animal model for evaluation of biomaterial for bone regeneration and dental implant osseointegration. From an ethical point of view, one sheep allows for up to 12 implants per animal, permitting to keep them alive at the end of the experiments. Level of Evidence II, Retrospective Study.

O objetivo do presente trabalho foi comparar e analisar os requisitos necessários para registro e as ações de tecnovigilância para implantes dentários nos EUA, na União Europeia e no Brasil. Após análise da literatura e das principais normas em vigor, observou-se a preocupação com o controle de riscos e a prevenção de falhas no uso dos implantes dentários. Nos EUA, o sistema de registro e tecnovigilância é centralizado e se verificam problemas de subnotificação e falhas na análise dos relatórios de notificação, bem como um intervalo de tempo longo entre a identificação dos problemas e a ação devido à extensão do processo administrativo. Na União Europeia, os poucos estudos identificados sugerem que o sistema regulatório oferece riscos aos pacientes devido à ausência de transparência entre os Órgãos Notificadores e à dificuldade em se articular a tecnovigilância entre os países. No Brasil, a tecnovigilância é centralizada, porém ainda é incipiente. O envelhecimento da população promove forte demanda por reabilitação oral dos pacientes, sobretudo os carentes, prevista no programa Brasil Sorridente. A demanda pelo serviço oferece uma oportunidade de expansão do mercado, mas detecta-se risco de entrada de produtos de baixa qualidade. Neste contexto, o aprimoramento das atividades de tecnovigilância de implantes dentários é necessário. -------------------------------------------------------------------------------------------- This study compared and analyzed, after reviewing the literature and the main legal regulations, the requirements for registration and the post-marketing surveillance activities of dental implants in the USA, the European Union and in Brazil. The legal regulations studied showed a concern for risk control and for prevention of failures in the use of dental implants. In the US, the system is centralized, which produces underreporting problems and flaws in the analysis of reporting, as well as a long time between problems identification and the action (due to the extension of the administrative process). In the European Union the few identified studies suggested that the regulatory system provides risks to patients related to the lack of transparency among notifying organs and to the difficulty in articulating the post-marketing surveillance among countries. In Brazil, the post-marketing surveillance is centralized, and is still in its infancy, having the “sentinel” hospitals and “Notivisa” as its main initiatives. Population ageing promotes strong demand for patients’ oral rehabilitation, especially the needy included in the “Smiling Brazil” program. The service demand may offer a market expansion opportunity, but it also poses a risk of low-quality products entry. In this context, the improvement of post-market surveillance activities of dental implants becomes a priority.

ABSTRACT Objective The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA) microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA). Material and Methods The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group) (n=5/period/group). After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance. Results The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p

Objective The objective of this study was to investigate the impact of two different commercially available dental implants on osseointegration. The surfaces were sandblasting and acid etching (Group 1) and sandblasting and acid etching, then maintained in an isotonic solution of 0.9% sodium chloride (Group 2). Material and Methods X-ray photoelectron spectroscopy (XPS) was employed for surface chemistry analysis. Surface morphology and topography was investigated by scanning electron microscopy (SEM) and confocal microscopy (CM), respectively. Contact angle analysis (CAA) was employed for wetting evaluation. Bone-implant-contact (BIC) and bone area fraction occupied (BAFO) analysis were performed on thin sections (30 μm) 14 and 28 days after the installation of 10 implants from each group (n=20) in rabbits' tibias. Statistical analysis was performed by ANOVA at the 95% level of significance considering implantation time and implant surface as independent variables. Results Group 2 showed 3-fold less carbon on the surface and a markedly enhanced hydrophilicity compared to Group 1 but a similar surface roughness (p>0.05). BIC and BAFO levels in Group 2 at 14 days were similar to those in Group 1 at 28 days. After 28 days of installation, BIC and BAFO measurements of Group 2 were approximately 1.5-fold greater than in Group 1 (p

This study’s aim was to evaluate the biocompatibility and bioabsorption of a new membrane for guided bone regeneration (polylactic-co-glycolic acid associated with hydroxyapatite and β-tricalcium phosphate) with three thicknesses (200, 500, and 700 µm) implanted in mice subcutaneously. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and the quantification of carbon, hydrogen and nitrogen were used to characterize the physico-chemical properties. One hundred Balb-C mice were divided into 5 experimental groups: Group 1—Sham (without implantation); Group 2—200 μm; Group 3—500 μm; Group 4—700 μm; and Group 5—Pratix®. Each group was subdivided into four experimental periods (7, 30, 60 and 90 days). Samples were collected and processed for histological and histomorphometrical evaluation. The membranes showed no moderate or severe tissue reactions during the experimental periods studied. The 500-μm membrane showed no tissue reaction during any experimental period. The 200-μm membrane began to exhibit fragmentation after 30 days, while the 500-μm and 700-µm membranes began fragmentation at 90 days. All membranes studied were biocompatible and the 500 µm membrane showed the best results for absorption and tissue reaction, indicating its potential for clinical guided bone regeneration.

O objetivo do presente trabalho foi comparar e analisar os requisitos necessários para registro e as ações de tecnovigilância para implantes dentários nos EUA, na União Europeia e no Brasil. Após análise da literatura e das principais normas em vigor, observou-se a preocupação com o controle de riscos e a prevenção de falhas no uso dos implantes dentários. Nos EUA, o sistema de registro e tecnovigilância é centralizado e se verificam problemas de subnotificação e falhas na análise dos relatórios de notificação, bem como um intervalo de tempo longo entre a identificação dos problemas e a ação devido à extensão do processo administrativo. Na União Europeia, os poucos estudos identificados sugerem que o sistema regulatório oferece riscos aos pacientes devido à ausência de transparência entre os Órgãos Notificadores e à dificuldade em se articular a tecnovigilância entre os países. No Brasil, a tecnovigilância é centralizada, porém ainda é incipiente. O envelhecimento da população promove forte demanda por reabilitação oral dos pacientes, sobretudo os carentes, prevista no programa Brasil Sorridente. A demanda pelo serviço oferece uma oportunidade de expansão do mercado, mas detecta-se risco de entrada de produtos de baixa qualidade. Neste contexto, o aprimoramento das atividades de tecnovigilância de implantes dentários é necessário.

Abstract The aim of this study is to evaluate the biocompatibility and osteoconductivity in surgical defects of sheep tibias filled with 1% strontium-containing nanostructured hydroxyapatite microspheres (SrHA), stoichiometric hydroxyapatite without strontium microspheres (HA), or blood clots. Santa Ines sheep were subjected to three perforations on the medial side of the left tibia. The biomaterials were characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) before implantation and by X-Ray Microfluorescence (µFRX) and Scanning Electron Microscopy (SEM) after sheep tibias implantation. Surgical defects were filled with blood clots (control), SrHA (Group 1) or HA (Group 2). After 30 days, 5-µm bone blocks were obtained for histological evaluation, and the blocks obtained from 1 animal were embedded in methylmethacrylate for undecalcified sections. Mononuclear inflammatory infiltrate remained mild in all experimental groups. Giant cells were observed surrounding biomaterials particles of both groups and areas of bone formation were detected in close contact with biomaterials. All groups showed newly formed bone from the periphery to the center of the defects, which the control, HA and SrHA presented 36.4% (± 21.8), 31.2% (± 14.7) and 26.2% (± 12.9) of newly formed bone density, respectively, not presenting statistical differences. In addition, the connective tissue density did not show any significant between groups. The SrHA showing a higher volume density of biomaterial (51.2 ± 14.1) present in the defect compared to HA (32.6 ± 8.5) after 30 days (p = 0.03). Microspheres containing 1% SrHA or HA can be considered biocompatible, have osteoconductive properties and may be useful biomaterials for clinical applications.

The white New Zealand rabbit (Oryctolagus cuniculus) is frequently used as a model for in vivo studies. However, information on precautions when using this animal as an experimental model is limited. This review of the literature covers the gamut from the selection of the animal model all the way to its death, and describes procedures for transporting, raising, breeding, housing, administering anesthesia and handling so as to rationalize the utilization of this species while exploiting its unique characteristics. Based upon the literature and our own experience with white New Zealand rabbits, we conclude that the rabbit is an adequate model for experimental surgery.O coelho branco da Nova Zelândia (Oryctolagus cuniculus) é freqüentemente utilizado como modelo em estudos in vivo. Contudo, as informações referentes aos cuidados no emprego deste animal como modelo experimental são limitadas. Esta revisão da literatura pretende rever a literatura desde a seleção do modelo animal até a sua morte, enfatizando, os procedimentos para transporte, criação, reprodução, comportamento, acomodação, anestesia e manejo dos animais, de forma a racionalizar a utilização desses animais reconhecendo as características próprias dessa espécie. Conclui-se que o coelho constitui um modelo adequado e viável para cirurgia experimental.

OBJETIVO: Os xenoenxertos são uma alternativa aos enxertos autogênicos e devem ser osteocondutores e biocompatíveis. Um estudo recente demonstrou que as características físicas e químicas das hidroxiapatitas encontradas no comércio não são condizentes com as descrições dos fabricantes. Este estudo avalia a biocompatibilidade e a osteocondução de um xenoenxerto derivado de osso medular bovino. MÉTODOS: Quinze coelhos adultos, pesando entre 2.500g e 3.000g cada um, foram anestesiados e submetidos a procedimentos cirúrgicos para criar três perfurações na tíbia, com 2 mm de diâmetro. Esses orifícios foram preenchidos com coágulo sanguineo, Osseus® e Bio-Oss®. Os animais foram sacrificados depois de 7, 14 e 28 dias. RESULTADOS: A análise histopatológica da interface de osso e biomaterial mostrou ligeira resposta inflamatória depois de 7 dias, que esteve ausente nos períodos subsequentes. Ambos os materiais foram parcialmente substituídos por tecido ósseo diretamente em contato com a superfície dos materiais, sem ocorrência de fibrose. CONCLUSÃO: Concluímos que ambos os materiais são biocompatíveis e absorvíveis, o que permite progressiva aposição óssea na superfície durante todo o período de avaliação.OBJECTIVE: Xenografts are an alternative to autogenous grafts and must be osteoconductive and biocompatible. A recent study has demonstrated that the physical and chemical characteristics of commercially available hydroxyapatites do not fit the manufacturers' descriptions. This study evaluates the biocompatibility and osteoconduction of a xenograft derived from bovine medullary bone. METHODS: Fifteen adult rabbits weighing between 2,500 g and 3,000 g each were anesthetized and subjected to surgical procedures to create three perforations in the tibia, with a diameter of 2 mm. These were filled with blood clot, Osseus® and Bio-Oss®. The animals were euthanized after 7, 14 and 28 days. RESULTS: Histopathological analysis of the interface between the bone and the biomaterial showed a slight inflammatory response after 7 days, which was absent in the subsequent periods. Both materials were partially replaced by bone tissue directly in contact with the surface of the materials, without the occurrence of fibrosis. CONCLUSION: We concluded that both materials are biocompatible and absorbable, allowing for progressive bone apposition on the surface throughout the evaluation period.