Alveolar Socket Research Articles

Local Single-Dose Teriparatide Administration for BRONJ Prevention: Insights from a Rat Model Study.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) presents significant clinical challenges with uncertain treatment outcomes. Teriparatide, a fragment of human parathyroid hormone, shows potential in prevention strategies for BRONJ. This study investigates the impact of a single local dose of teriparatide on BRONJ prevention in an animal model. BRONJ was induced on 26 male Wistar rats via intraperitoneal injections of 0.06mg/kg Zoledronic acid weekly for four weeks. Following tooth extraction under general anesthesia, rats were divided into two groups: one received teriparatide via Gelatamp in the tooth socket and the other as a local injection in the vestibule. Control groups received the treatment without teriparatide. Histopathological assessments for bone remodeling, osteoclast number, inflammation, angiogenesis, and necrosis were performed after four weeks. Histopathological analysis indicated a significant improvement in bone remodeling and new bone formation in both treatment groups compared to controls, with notably better outcomes in the injection group (p = 0.01). Necrosis in the Gelatamp group was significantly higher in the control group than in the treatment group (p = 0.01), and bone formation was significantly higher in the injection group compared to the Gelatamp group (p = 0.03). Local administration of teriparatide significantly enhances bone remodeling and reduces necrosis, suggesting a potential role in the prevention of BRONJ. These findings support further clinical investigation into teriparatide as a preventive strategy against BRONJ.

Immediate implantation of simple taper retentive implants in chronic apical infected teeth in the posterior region: a 5-year clinical observation.

This study aims to evaluate the mid- and long-term clinical efficacies of simple taper retentive implants for immediate placement in chronic apical infected teeth in the posterior region. A total of 36 patients with 41 simple taper retentive implants were included in the study conducted. These patients underwent immediate implant treatment for teeth with chronic apical infection in the posterior region. The soft and hard tissues surrounding the implants were assessed and documented over a period of 5 years following the completion of crown restoration. During the 5 years follow-up period, one implant failed with mobility, and the implant survival rate was 97.6%. The mean marginal bone resorption was (-0.74±1.03) mm from the immediate post-implant placement to the immediate post-crown restoration, and the difference in marginal bone heights between the two time points was statistically significant (P<0.05). The mean marginal bone resorption was (-0.21±0.70) mm from the immediate post-crown restoration to the 5-year post-crown restoration, and the difference in marginal bone height between the two time points was not statistically significant (P>0.05). No significant difference (P>0.05) was observed in bone resorption between mesial and distal, maxillary and mandibular, different tooth positions, and different implant lengths. The soft tissue surrounding the implants remained healthy at the 5 years follow-up period, one implant exhibited peri-implantitis, and no mechanical complications were observed. The overall satisfaction of patients was good. Immediate placement of simple taper retentive implants after thorough debridement of chronic infected alveolar socket in the posterior region can achieve good mid- and long-term clinical outcomes after 5 years of loading. The soft and hard tissues were maintained in a steady state, which expanded the indications for immediate implantation.

Replantation of young permanent teeth: Techniques and Management of traumatic pulp exposure

Introduction: Dental traumatology is one of the most challenging pediatric treatment aspects. Avulsion of young permanent teeth is a rare and serious traumatic dental injury that needs immediate and complex management. Tooth avulsion is a severe dental trauma defined by complete displacement of the tooth out of its alveolar socket. The primary approach to managing such cases is tooth replantation. The management of replanting the tooth according by the guideline such as the extra oral time which should be very short, the time of pulp removal after replantation, and the appropriate storage medium. Case History: A 9-year-old male presented with history of fall from the slide he played and injuries sustained to the maxillary region. He was referred to the IGD RSKGM-P Airlangga Surabaya and complained that his upper tooth was loose from its socket around 2 hours of trauma. The tooth was soaked in normal saline. Discussion: The optimal treatment option following an avulsion injury is to replant the avulsed tooth immediately. The duration of the extraoral period and the storage conditions of the tooth significantly influence the prognosis. The prognosis for avulsion injuries is highly dependent on timely intervention, appropriate treatment planning and techniques, and effective emergency management. Post-replantation, regular monitoring is essential to assess for ankylosis, resorption, mobility, and vitality of the tooth. Conclusion: Successful replantation of young permanent teeth with traumatic pulp exposure relies on timely intervention, proper technique, and careful postoperative management.

Justifying the method chosen for bone bed preparation for immediate dental implantation

Despite the progress achieved in dental implantation, the problems of reducing the number of complications after implants placement and increasing their service life remain relevant. It is known that inflammatory complications that arise after intraosseous dental implantation serve as a serious aggravating factor affecting the stability and safety of the implant, which creates unfavorable conditions for further prosthodontics.The aim of the study is to conduct a comparative analysis of the different-method effectiveness of dental alveoli preparation based on molecular-genetic microbiological research.Research methods: clinical, molecular genetic, microbiological.A comparative analysis of the different-method effectiveness of dental alveoli preparation based on the results of a molecular genetic microbiological study is presented in the research. A mandatory stage of sanitation of the operating area is found by the presented research results. The mechanical method using a spherical bur and a physiodispenser, the piezosurgical method using a spherical nozzle with a diamond coating can be a method of choice for dental alveoli preparation.

Management of Vestibular Bone Fenestration with Periosteal Inhibition (PI) Technique During Alveolar Socket Preservation: A Case Report

Management of Vestibular Bone Fenestration with Periosteal Inhibition (PI) Technique During Alveolar Socket Preservation: A Case Report

Dental pulp stem cell‑derived extracellular vesicles loaded with hydrogels promote osteogenesis in rats with alveolar bone defects.

Alveolar bone defects caused by inflammation, trauma and tumors adversely affect periodontal health, causing tooth loosening or dentition defects, thus affecting denture or implant repair. Advancements in tissue engineering technology and stem cell biology have significantly improved the regenerative reconstruction of alveolar bone defects. The multiple trophic activities of extracellular vesicles (EVs) produced by mesenchymal stem cells play important roles in exerting their therapeutic effects. Several studies have reported the role of dental pulp stem cells (DPSCs) in bone regeneration, but the regenerative effects of DPSC‑EVs on alveolar bone defects are unclear. In the present study, the osteogenic effects of DPSC‑EVs on Hertwig's epithelial root sheath (HERS) cells in vitro and their osteoinductive effects in an alveolar bone defect rat model were investigated. The results showed that DPSC‑EVs significantly promoted the expression of osteogenic genes, such as runt‑related transcription factor 2 and alkaline phosphatase, and increased the osteogenic differentiation capability of HERS. These findings suggested that transforming growth factor β1 inhibition decreased DPSC‑EV‑induced Smad, MAPK and ERK phosphorylation in HERS. In vivo, DPSC‑EV‑loaded hydrogels were transplanted into the alveolar sockets of Sprague‑Dawley rats and observed for eight weeks. The new bone grew concentrically in the DPSC‑EV or DPSC‑EV‑loaded hydrogel group, with greater bone mass than that in the control group, and the bone volume/total volume increased notably. The results confirmed the osteogenic and osteoinductive effects of DPSC‑EVs and DPSC‑Exo‑loaded hydrogels on alveolar bone defects. Due to their low immunogenicity, high stability, good biocompatibility and osteogenic propensity, DPSC‑EV‑loaded hydrogels are a safe cell‑free therapeutic approach for defective alveolar bone regeneration.

Cone Beam Computed Tomography Evaluation of Socket Healing After Third Molar Germ Extraction: A Case Series Study Including Adolescents with Osteogenesis Imperfecta Type I Treated with Bisphosphonates and Healthy Age-Matched Subjects

Bisphophonates (BPs) are widely used in Osteogenesis imperfecta (OI). Cone Beam Computed Tomography (CBCT) shows clinical usefulness in evaluating impacted teeth and adjacent structure relationships, extraction socket healing, bone mineral density (BMD) and BP-related jaw osteonecrosis (BRONJ). The aim of the study was to compare alveolar sockets and the adjacent bone area before and after third molar extraction in OI type I (OI-I) adolescents treated with BPs and age-matched healthy subjects (HSs) by CBCT. Methods: Five adolescents with genetically proven OI-I treated with BPs (three males and two females, mean age: 15.2 ± 1.78 years) and four age-matched healthy subjects (two males and two females, mean age: 15.5 ± 1.29 years) were included in this study. Eight Regions of Interest (ROIs) were evaluated: between 3.7 and 3.8 (ROI-1) and 4.7 and 4.8 (ROI-2); after 3.8 (ROI-3) and 4.8 (ROI-4); alveolar sockets 3.8 (ROI-5) and 4.8 (ROI-6); left (ROI-7) and right (ROI-8) cortical bone. Results: ROIs were evaluated on both sides of the mandible for all the subjects except one OI patient in which CBCTs were performed pre- and-post third molar extraction only on the right side. CBCT was performed 12.8 ± 4.60 and 11.5 ± 2.51 days before and 8.0 ± 1.41 and 7.7 ± 0.5 months after extraction in OI-I and HSs, respectively. BPs were discontinued 62.0 ± 36.5 months before extraction. None of the OI-I adolescents developed BRONJ. Statistically significant greater values were observed in OI-I for ROI-1 and -2 (p = 0.0464), ROI-3 and -4 (p = 0.0037) and ROI-7 and -8 (p = 0.0079) after extraction. Conclusions: This descriptive study confirms that, in OI-I adolescents treated with BPs, third molar extraction is safe, and socket healing occurs properly. In addition, it demonstrates that, if the same device and imaging conditions are used and comparisons to predetermined standard values are avoided, CBCT can be used to monitor BMD changes. The significant greater BMD observed for different ROIs in OI-I could reflect the increased secondary mineralization related to the BP-dependent reduction in bone turnover.

Morphological characteristics of the unique periodontal structure in dolphins.

Although toothed whales have dentition peculiar to mammals, little attention has been paid to the periodontal tissues that support these characteristic teeth. In this study, we clarified the anatomical characteristics of the periodontal tissue in several species of Delphinidae through three-dimensional observation using micro-computed tomography, histological observations using decalcified sections, and immunohistochemical analysis. The results indicated that the teeth and the periodontal tissues of dolphins are morphologically unique among mammals. The alveolar bone was both crude and spongy. The lamina dura, a radiopaque line observed in the alveolar bone of common mammals, was thin in dolphins, and the teeth were attached to the trabeculae with the periodontal ligament (PDL). The alveolar sockets were massive for the size of the teeth. The PDL, a collagen fiber that fills the periodontal space, was well-developed and peculiarly divided into two layers. The inner layer fibers radially spread out from the cementum, similar to the PDL in common mammals. However, the outer layer fibers penetrate the spongy bone in a complicated manner. The interstitial space between the inner and outer layers contained nerve fiber bundles that were thicker than those found in the PDL of other mammals. Sensory receptor-like structures were observed at the terminal ends of the nerve fibers. These findings indicated that the dolphin PDL is more sensitive to dental stimuli than those of other mammals, suggesting that the dolphin dentition plays a functional role as a sensory receptor, similar to tactile hair.

Exosomes from Adipose-Derived Mesenchymal Stromal Cells Prevent Medication-Related Osteonecrosis of the Jaw by Inhibiting Macrophage M1 Polarization and Pyroptosis.

Exosomes from mesenchymal stromal cells (MSCs) can prevent the development of medication-related osteonecrosis of the jaw (MRONJ) by promoting tooth socket wound healing; however, the exact mechanism remains to be clarified. In this study, our aim was to explore the mechanisms of exosomes derived from adipose-derived mesenchymal stromal cells (ADSCs) in preventing MRONJ by focusing on macrophage M1 polarization and pyroptosis. The MRONJ model was established by theadministration of zoledronate and tooth extraction. Exosomes isolated from the supernatant of ADSCs were mixed with hydrogel and locally injected into the extraction site after tooth extraction. Stereoscope observations, micro computed tomography (microCT), and histological analysis were used to assess tooth socket wound healing. The results showed that exosomes could effectively avoid MRONJ via accelerating gingival wound healing and tooth socket bone regeneration. Mechanistically, zoledronate triggered the NF-κB signaling pathway and promoted p65 transferring into the nucleus in macrophages, resulting in macrophage M1 polarization and pyroptosis-mediated tissue inflammation, while exosomes could reduce macrophage pyroptosis and pro-inflammation cytokines release by suppressing the NF-κB/NLRP3/IL-1β axis. Additionally, IL-1RA derived from exosomes plays a key role in preventing MRONJ. Pyroptosis-related and inflammatory-related processes were upregulated in MRONJ patients further confirmed by assessing MRONJ gingival samples and healthy gingival tissues. ADSCs-derived exosomes could effectively promote tooth socket healing and prevent MRONJ by inhibiting M1 macrophage activation and pyroptosis by blocking the NF-κB/NLRP3/IL-1β axis.

Comparative Accuracy of dCAIS and Freehand Techniques for Immediate Implant Placement in the Maxillary Aesthetic Zone: An In Vitro Study

ObjectiveTo evaluate the accuracy of immediate implant placement in fresh extraction sockets in the maxillary aesthetic zone using a dynamic computer-assisted implant surgery system (dCAIS), with the evaluation of possible deviations versus freehand placement. MethodsA total of 18 implants were placed by an experienced surgeon in fresh extraction sockets of anterior teeth in 6 maxillary models. Nine implants were placed using the dCAIS system and 9 implants were placed using the conventional freehand technique. The following outcome parameters were measured and compared: positional deviation at entry, apex point and angular deviations between planned and placed implant position. Surgery time was measured for each procedure. Descriptive and statistical analyses were performed on all outcome parameters. ResultsGlobal entry deviations were not significantly different between the two techniques (p=0.078). dCAIS resulted in significantly more accurate implant placement in terms of global apex deviation with values of 1.28±0.36 mm and angular deviations with values of 1.29±0.64°, compared to 2.06±0.60 mm and 5.05±2.54° with freehand placement (p<0.001). The dental implant placement time was approximately three times longer when using dCAIS (10.99 ± 3.43 min) versus freehand (3.25± 0.63 min) (p < 0.001). ConclusionsdCAIS achieved more precise immediate implant placement in terms of apex deviation and angulation than freehand placement, but increased the surgery time. Clinical significancedCAIS provides greater accuracy in the placement of immediate implants in the maxillary aesthetic zone following prosthetic-driven digital planning compared to freehand surgery.

ALVEOLITE COMO COMPLICAÇÃO PÓS OPERATÓRIA DE EXODONTIAS

Alveolitis is a common postoperative complication resulting from complex extractions, particularly of lower third molars, characterized by intense pain and inflammation of the dental socket. This study aims to analyze the incidence, risk factors, treatments, and preventive measures for this condition, which significantly impacts patients’ quality of life. The methodology employed was a narrative literature review, using databases such as PubMed, SciELO, and Google Scholar, with descriptors such as “alveolitis,” “surgery oral,” and “osteitis.” The results indicate that the etiology of alveolitis is multifactorial, with factors such as smoking, the use of oral contraceptives, and surgical trauma contributing to its development. Treatment varies depending on the severity of the condition, with the application of dressings, irrigation with antiseptic solutions, and, in more severe cases, the use of antibiotics. Preventive measures, such as maintaining good oral hygiene and adopting atraumatic surgical techniques, proved effective in reducing the occurrence of alveolitis.

Effect of Local Zoledronic Acid Application in Alveolar Bone Healing: An Experimental Study.

This experimental study aimed to assess the three-dimensional and histological changes of the alveolar socket with local application of ZA. Nine male New Zealand white rabbits were randomly allocated into 4-, 8-, and 12-week groups after the extraction of 4 incisor teeth. The upper and lower right sockets were filled with ZA + collagen sponge (ZA-CS group), while the left sockets were filled with collagen sponge alone (CS group) postoperatively. At 4, 8, and 12 weeks (T1, T2, and T3) after the extraction, radiographic and histomorphometric evaluations were conducted for both groups. The increase in alveolar bone density of the ZA-CS group at T2 and T3 was significantly higher than the CS group (P＜0.01). Three-dimensional evaluations demonstrated no statistically significant differences in ridge height and width between the 2 groups at T2 and T3. On histological evaluation, the ZA-CS group included significantly fewer TRAP-positive cells than the CS group at T1 (P＜0.05). In ALP staining, all cases in both groups were classified as positive at each time point. Masson trichrome staining showed significantly higher mean red collagen volume fraction in the ZA-CS group (76.09%, 79.64%) than in the CS group (66.17%, 69.22%) at T2 and T3, respectively (P＜0.05 and ＜0.01). Although local ZA application with collagen sponge did not reduce alveolar ridge contraction, it improved the bone density and maturity of newly formed bone after tooth extraction.

Comparative Study of Photobiomodulation Effects on Alveolar Socket Hard Tissue Healing in Rats: Application of 980 nm Versus 810 nm Lasers.

Background: This study aimed to explore the differential effects of photobiomodulation (PBM) via 980 nm and 810 nm lasers on the hard tissue healing of rat alveolar sockets, with a focus on a comparative analysis of hard tissue regeneration and osteogenic gene expression. Objective: This study aimed to explore the effects of PBM using 980 nm and 810 nm lasers on hard tissue healing of rat alveolar sockets, focusing on hard tissue regeneration and osteogenic gene expression. Materials and Methods: Thirty-six male Wistar rats (5 weeks old) had both right and left maxillary first molars extracted. Post extraction, the right alveolar sockets received PBM treatment with either 980 nm (0.3 W, 18 J/cm2) or 810 nm (0.1 W, 6 J/cm2) lasers for seven days, whereas the left sockets served as controls. Rats were euthanized on days 3, 7, 14, and 28 for histopathological, immunohistochemical, micro computed tomography (micro-CT), and quantitative polymerase chain reactionanalyses. Results: On day 3, early granulation tissue, neovascularization, and inflammatory cell aggregates were observed in all groups. By day 7, active osteoclasts and osteoblasts were noted, with a significant increase in CD31-positive cells in the 980 nm group (p < 0.05). Day 14 showed new bone formation, and by day 28, increased cancellous bone and collagen content were present in all groups, with no significant differences between them (p > 0.05). Gene expression analysis revealed higher BMP-2 and Runx-2 levels in laser-treated groups on day 14 (p < 0.05), with the 980 nm group having higher BMP-2 levels than the 810 nm group (p < 0.05). Bone sialoprotein expression was higher in laser-treated groups on days 14 and 28 (p < 0.05), and osteocalcin expression was highest in the 980 nm group on both days (p < 0.05). Micro-CT analysis showed no significant differences among groups in bone mineral density, bone surface (BS)/bone volume (BV), or bone volume (BV)/TV (total volume) indices. Conclusion: PBM with 980 nm and 810 nm lasers promotes early-stage hard tissue healing in extraction sockets, with the 980 nm laser more effectively enhancing osteogenic gene expression, suggesting its potential as an adjunctive therapy in dental and oral surgery.

Micro-XCT analysis of anatomical features and dimensions of the incisive canal: implications for dental implant treatment in the anterior maxilla

BackgroundThis study used micro-focus X-ray Computed Tomography (micro-XCT) to examine the anatomical differences and dimensions of the maxillary incisive canal (MIC) in a South African population. The accurate imaging yielded dependable results that support earlier research and enhance anterior maxilla surgery planning. Furthermore, these anatomical features are compared between various racial and gender groupings in the study.MethodsUsing a micro-XCT scanner, 108 human cadaver skulls from the Pretoria Bone Collection were scanned and included in the study. Advanced volume rendering software was employed for measuring the MIC length, diameter, shape, and the buccal bone wall measurements in relation to the MIC.ResultsSignificant anatomical variation in the size and shape of the MIC was identified in the population, with variations seen between racial and gender groups. The incisive foramen (ICO) mean diameter was 6.61 mm, and the MIC length varied from 4.96 to 20.10 mm. There were significant differences in the buccal alveolar bone height between different ethnic groups and gender. Regarding morphological patterns in coronal and sagittal views, single canals were more common in the black population while Y-shaped canals were more common in the white population. The study also introduced a new metric by measuring the mean distances between teeth #11 and #21 and the ICO (1.83 mm and 1.88 mm respectively).ConclusionsThe complex anatomical differences of the MIC in a South African population were clarified. Clinicians should be aware of tooth sockets in near proximity to the MIC and perform accurate preoperative assessment using sophisticated 3-D imaging and preferable guided implant placement in the anterior maxilla.

NLRP3 deficiency improves bone healing of tooth extraction sockets through SMAD2/3-RUNX2 mediated osteoblast differentiation.

Impaired bone healing following tooth extraction poses a significant challenge for implantation. As a crucial component of the natural immune system, the NLRP3 inflammasome is one of the most extensively studied Pattern-Recognition Receptors (PRRs), and is involved in multiple diseases. Yet, the role of NLRP3 in bone healing remains to be clarified. Here, to investigate the effect of NLRP3 on bone healing, we established a maxillary first molar extraction model in wild-type (WT) and NLRP3KO mice using minimally invasive techniques. We observed that NLRP3 was activated during the bone repair phase, and its depletion enhanced socket bone formation and osteoblast differentiation. Moreover, NLRP3 inflammasome activation was found to inhibit osteogenic differentiation in alveolar bone-derived mesenchymal stem cells (aBMSCs), an effect mitigated by NLRP3 deficiency. Mechanistically, we established that SMAD2/3-RUNX2 signaling pathway is a downstream target of NLRP3 inflammasome activation, and SMAD2/3 knockdown partially reversed the significant decrease in expression of RUNX2, OSX, and ALP induced by NLRP3. Thus, our findings demonstrate that NLRP3 negatively modulates alveolar socket bone healing and contribute to the understanding of the NLRP3-induced signaling pathways involved in osteogenesis regulation.

A small venomous reptile from the Late Triassic (Norian) of the southwestern United States.

Reptile feeding strategies encompass a wide variety of diets and accompanying diversity in methods for subduing prey. One such strategy, the use of venom for prey capture, is found in living reptile clades like helodermatid (beaded) lizards and some groups of snakes, and venom secreting glands are also present in some monitor lizards and iguanians. The fossil record of some of these groups shows strong evidence for venom use, and this feeding strategy also has been hypothesized for a variety of extinct reptiles (e.g., archosauromorphs, anguimorphs, and a sphenodontian). However, evidence of systems for venom delivery in extinct groups and its evolutionary origins has been scarce, especially when based on more than isolated teeth. Here, we describe a potentially venomous new reptile, Microzemiotes sonselaensis gen. et sp. nov., from a partial left dentary recovered from the Sonsela Member of the Chinle Formation (middle Norian, Upper Triassic) of northeastern Arizona, U.S.A. The three dentary teeth have apices that are distally reclined relative to their bases and the tip of the posteriormost tooth curves mesially. The teeth show subthecodont implantation and are interspaced by empty sockets that terminate above the Meckelian canal, which is dorsoventrally expanded posteriorly. Replacement tooth sockets are positioned distolingually to the active teeth as in varanid-like replacement. We identify this new specimen as a diapsid reptile based on its monocuspid teeth that lack carinae and serrations. A more exclusive phylogenetic position within Diapsida is not well supported and remains uncertain. Several features of this new taxon, such as the presence of an intramandibular septum, are shared with some anguimorph squamates; however, these likely evolved independently. The teeth of the new taxon are distinctively marked by external grooves that occur on the entire length of the crown on the labial and lingual sides, as seen in the teeth of living beaded lizards. If these grooves are functionally similar to those of beaded lizards, which use the grooves to deliver venom, this new taxon represents the oldest known reptile where venom-conducting teeth are preserved within a jaw. The teeth of the new species are anatomically distinct from and ~10x smaller than those of the only other known Late Triassic hypothesized venomous reptile, Uatchitodon, supporting venom use across multiple groups of different body size classes. This new species represents the third Late Triassic reptile species to possibly have used envenomation as a feeding (and/or defensive) strategy, adding to the small number of venomous reptiles known from the Mesozoic Era.

Tomographic and Electron Microscopy Description of Two Bone-Substitute Xenografts for the Preservation of Dental Alveoli.

After tooth extraction, bone levels in the alveoli decrease. Using a bone substitute can help minimize this bone loss. The substitute can be sourced from a human or animal donor or synthetically prepared. In this study, we aimed to address the following PICOS question: In patients needing dental alveolar preservation for implant placement, how does alveolar preservation using a bovine hydroxyapatite bone xenograft with collagen compare to a xenograft without collagen in terms of changes in alveolar height and width, bone density, and the characteristics of the bone tissue observed in biopsies taken at 6 months? We evaluated two xenograft-type bone substitutes for preserving post-extraction dental sockets using tomography and microscopy to answer that question. A total of 18 dental alveoli were studied: 11 preserved with a xenograft composed of apatite (InterOss) and 7 with a xenograft composed of apatite-collagen (InterOss Collagen). Tomographic controls were performed at 1 and 6 months, and microscopic studies were performed on 13 samples. The biopsies were examined with scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). A Multivariate Analysis of Variance (MANOVA) was conducted in the statistical analysis, revealing a significant increase in bone density over time (p = 0.04). Specifically, bone density increased from an average of 526.14 HU at 30 days to 721.96 HU at 60 days in collagen-free samples. However, no statistically significant differences in height or width were found between groups. The MANOVA results indicated that the overall model had a low predictive ability for height, width, and density variables (R-squared values were low), likely due to sample size limitations and the complexity of bone tissue dynamics. On the other hand, FTIR analysis revealed the presence of phosphate groups, carbonates, and amides I, II, and III, indicative of inorganic (hydroxyapatite) and organic (type I collagen) materials in the xenografts. TGA and DSC showed high thermal stability, with minimal mass loss below 150 °C. Finally, both xenografts were influential in alveolar bone regeneration after extraction without significant differences. The trend of increasing collagen density suggests an effect that requires further investigation. However, it is recommended that the sample size be increased to enhance the validity of the results.

Dental morphology evolution in early peratheriines, including a new morphologically cryptic species and findings on the largest early Eocene European metatherian

ABSTRACT The initial stages of the evolutionary history of peratheriines, the European herpetotheriid metatherians, are largely unknown, primarily due to their limited morphological dental disparity throughout the Palaeogene, coupled with significant intraspecific variation. Based on eleven molars, we document a new early peratheriine species, Peratherium musivum sp. nov. which is larger than and morphologically similar to the earliest peratheriine, Peratherium constans (MP7). Subtle molar characters are shared with the largest early Eocene peratheriine, Peratherium maximum comb. nov. We illustrate the importance of studying possible changes in molar cusp – basin proportions and correlated characters that occured during peratheriine evolution. Peratherium musivum sp. nov. which spanned only part of the MP7-MP8 + 9 time interval, and the ~MP8 + 9 Peratherium maximum comb. nov. were probably widespread in Western Europe. The description of a well-preserved mandible of the latter, from La Borie (~MP8 + 9), reveals original features concerning relative size and shape of dental alveoli, partly corroborated using isolated molars. These traits are absent in the younger, most representative species of both peratheriine genera, Peratherium and Amphiperatherium. Based on the aforementioned data and a critical review, it is demonstrated that peratheriine genera lack consistent definitions, so that the Peratherium/Amphiperatherium dichotomy is plausibly inapplicable to early Eocene representatives. This article is registered in ZooBank under urn:lsid:zoobank.org:pub:A2B4DE58-855C-4CB8-BC1D-C9677E6DF97D

Comparative Histological Analysis of Dentine-Derived Tooth Grafts in Maxillary vs Mandibular Socket Preservation: A Retrospective Study of 178 Cases.

(1) Background: In recent years, there has been a growing interest in tooth-derived materials as valuable alternatives to synthetic biomaterials for preventing alveolar ridge dimensional changes. This study aimed to evaluate the histological and clinical differences between alveolar ridge preservation procedures in the maxilla and mandible using demineralized dentin treated with Tooth Transformer®. (2) Methods: A total of 178 patients in good general health were enrolled, with 187 post-extractive sockets lacking buccal and/or palatal bone walls. Alveolar socket preservation procedures and histological evaluations were performed. The sites were divided into two groups: Group A (99 mandibular samples) and Group B (108 maxillary samples). After 5 months (±1 month), single bone biopsies were performed for histologic and histomorphometric analysis. (3) Results: Clinical outcomes demonstrated a good healing of hard and soft tissues with an effective maintenance of bone architecture in both groups. Histomorphometric analysis revealed a total bone volume of 50.33% (±14.86) in Group A compared to 43.53% (±12.73) in Group B. The vital new bone volume was 40.59% (±19.90) in Group A versus 29.70% (±17.68) in Group B, with residual graft dentin material volume at 7.95% (±9.85) in Group A compared to 6.75% (±9.62) in Group B. (4) Conclusions: These results indicate that tooth-derived material supports hard tissue reconstruction by following the structure of the surrounding bone tissue. A 6.8% difference observed between the maxilla and mandible reflects the inherent disparities in natural bone structures in these regions. This suggests that the bone regeneration process after tooth extraction adheres to an anatomical functional pattern that reflects the specific bone characteristics of each area, thus contributing to the preservation of the morphology and functionality of the surrounding bone tissue.

DENTAL IMPLANT INSERTION – HOW TO PLAN AND PREDICT SUCCESS

For decades, implant placement protocols and implant loading protocols were addressed independently from one another. With the healing of the alveolar socket post-extraction, the implant placement protocol and the surgical technique are determining factors for selection of an appropriate implant loading protocol; these should be considered as codependent variables. The objectives of the study were to highlight factors influencing the implant placement and loading protocol. Material and methods. The retrospective study included patients presented for teeth extraction and oral rehabilitation treatment plan that included implant restorations between October 2020 and October 2022. Factors influencing implant placement and loading protocol were analyzed for each case. Representative cases were presented with details. Results. 10 clinical cases were included in the study, in which implanto-prosthetic treatment was performed using different insertion protocols. Three representative cases were presented. Conclusions. Implant insertion protocols are closely related to multiple factors, so the clinician nowadays must carefully decide the time elapsed from tooth extraction to the moment of dental implant insertion. The insertion protocol should be chosen only if the factors influencing that protocol led to the success of the implant-prosthetic treatment.