Tooth Extraction In Rats Research Articles

Efficacy and safety of a new heterologous fibrin biopolymer on socket bone healing after tooth extraction: An experimental pre-clinical study.

To assess the efficacy of heterologous fibrin biopolymer (HFB) in promoting alveolar bone healing after tooth extraction in rats. The upper right incisors of 48 Wistar rats were extracted. Toothless sockets were filled with HFB (HFBG, n = 24) or blood clot (BCG, n = 24). The tooth extraction sites were subjected to micro-computed tomography (micro-CT), histological, histomorphometric and immunohistochemical (for Runt-related transcription factor 2/Runx2 and tartrate-resistant acid phosphatase/TRAP) analyses on days 0, 7, 14 and 42 after extraction. Socket volume remained similar between days 0 and 14 (69 ± 5.4 mm3), except in the BCG on day 14, when it was 10% lower (p = .043). Although the number of Runx2+ osteoblasts was high and similar in both groups (34 × 102 cells/mm2), the HFBG showed lower inflammatory process and osteoclast activity than BCG at 7 days. On day 14, the number of Runx2+ osteoblasts remained high and similar to the previous period in both groups. However, osteoclast activity increased. This increase was 55% lower in the HFBG than BCG. In the BCG, the presence of an inflammatory process and larger and numerous osteoclasts on day 14 led to resorption of the alveolar bone ridge and newly formed bone. On day 42, numbers of Runx2+ osteoblast and TRAP+ osteoclasts decreased dramatically in both groups. Although the BCG exhibited a more mature cortical bone formation, it exhibited a higher socket reduction (28.3 ± 6.67%) and smaller bone volume (37 ± 5.8 mm3) compared with HFBG (socket reduction of 14.8 ± 7.14% and total bone volume of 46 ± 5.4 mm3). HFB effectively suppresses osteoclast activity and reduces alveolar bone resorption compared with blood clot, thus preventing three-dimensional bone loss, particularly during the early healing period. HFB emerges as a promising biopharmaceutical material for enhancing healing processes after tooth extraction.

A smart band-aid with temperature and reactive oxygen species dual-responsiveness for synergistic mechanical and pharmacological therapy of chronic wounds

In this study, a dual-responsive multifunctional band-aid comprising a force-induced shrinkage layer and a drug-treated layer has been developed, characterized by its on-demand drug release. Evaluated through the pig skin the force-induced shrinkage layer facilitates active wound closure by forming stable adhesion to the skin. Afterward, the layer could provide mechanical force simulating the embryonic skin in response to temperature changes. Concomitantly, confronting the increased levels of reactive oxygen species (ROS) at the wound site, the drug-treated layer made of an ROS-responsive hydrogel, promptly releases zinc oxide (ZnO) and catalase (CAT) to exert antibacterial and anti-inflammatory stress effects, ultimately accelerating the healing process of chronic wounds. More important, this versatile hydrogel-based band-aid demonstrates remarkable efficacy in both bacteria-infected rat wounds and rat tooth extraction wounds. Overall, the versatility of this approach presents a comprehensive and convenient strategy for the treatment of clinical chronic wounds.

4-Octyl itaconate promotes alveolar ridge preservation following tooth extraction.

The search for medications that can effectively reduce alveolar bone loss following tooth extraction is of great interest. This study aimed to observe the roles of 4-octyl itaconate (4-OI) in RANKL-induced osteoclastogenesis of bone marrow macrophages (BMMs) in vitro. Mandibular second molars were extracted to evaluate whether 4-OI could alleviate alveolar bone loss. 4-OI inhibited RANKL-induced osteoclastogenesis and promoted Nrf2 expression in bone marrow macrophages in vitro. Positive Nrf2 expressions were observed in inflammatory cells and osteoclasts in vivo. Treatment with 4-octyl itaconate increased Nrf2 expression, resulting in reduced inflammatory infiltration and osteoclastic activity after tooth extraction. Furthermore, increased expression of OCN and enhanced-alveolar bone healing of extraction socket were observed in the 4-OI group compared to the control group. Our results suggested that 4-OI could serve as a promising pharmacologic candidate for alveolar ridge preservation by alleviating alveolar bone loss following tooth extraction in rats.

An injectable and coagulation-independent Tetra-PEG hydrogel bioadhesive for post-extraction hemostasis and alveolar bone regeneration

Effective control of post-extraction hemorrhage and alveolar bone resorption is critical for successful extraction socket treatment, which remains an unmet clinical challenge. Herein, an injectable Tetra-PEG hydrogel that possesses rapid gelation, firm tissue adhesion, high mechanical strength, suitable degradability, and excellent biocompatibility is developed as a sutureless and coagulation-independent bioadhesive for the management of extraction sockets. Our results demonstrate that the rapid and robust adhesive sealing of the extraction socket by the Tetra-PEG hydrogel can provide reliable protection for the underlying wound and stabilize blood clots to facilitate tissue healing. In vivo experiments using an anticoagulated rat tooth extraction model show that the hydrogel significantly outperformed clinically used cotton and gelatin sponge in hemostatic efficacy, wound closure, alveolar ridge preservation, and in situ alveolar bone regeneration. Histomorphological evaluations reveal the mechanisms for accelerated bone repair through suppressed long-term inflammation, elevated collagen deposition, higher osteoblast activity, and enhanced angiogenesis. Together, our study highlights the clinical potential of the developed injectable Tetra-PEG hydrogel for treating anticoagulant-related post-extraction hemorrhage and improving socket healing.

The Effect Of Black Cumin Nanoemulgel (Nigella sativa) On Fibroblasts In Post-Tooth Extraction Wound Healing In Mice

Background: Tooth extraction is said to be successful when accompanied by a good wound healing process. Innovation for post-tooth extraction wound treatment is necessary. Black cumin has active ingredients that function as anti-inflammatories. The formulation used is nanoemulgel because it has the advantages of stability and good adhesion. Objective: To evaluate the effect of black cumin nanoemulgel on the number of fibroblasts in the wound healing process after tooth extraction in rats. Methods: This study was conducted using post-test only control group design with a total sample of 22 samples divided into 4 groups with each group totaling 5 samples and 2 samples as a drop out. The application is carried out as much as 3 times a day for 5 days. Tissue collection from experimental animals was carried out and then histology preparations were made. Calculations of fibroblast were carried out using hematoxylin eosin (HE) staining and carried out in the apical 1/3 of the 3 visual fields with a V pattern. Statistical tests used are the One-Way Anova test and the Post Hoc LSD test. Results: There was significant difference in the number of fibroblasts between groups (p = 0.000). Black cumin nanoemulgel concentration of 15% showed highest number of fibroblasts. Conclusion: Nanoemulgel black cumin (Nigella sativa) 15% can increase the number of fibroblasts in wound healing post tooth extraction in rats. Nanoemulgel black cumin (Nigella sativa) 15% have the potential to accelerate wound healing process by increasing the number of fibroblasts.

SDF-1 involvement in orthodontic tooth movement after tooth extraction

The stromal cell-derived factor 1 (SDF-1)/chemokine receptor type 4 (CXCR4) axis plays a key role in alveolar bone metabolism during orthodontic tooth movement (OTM). Herein, the effects of the SDF-1/CXCR4 axis on the regional acceleratory phenomenon (RAP) in OTM velocity and on changes in the surrounding periodontium after adjacent tooth extraction in rats were investigated. Six-week-old male Wistar/ST rats underwent left maxillary first molar (M1) extraction and mesial OTM of the left maxillary second molar (M2) with a 10-g force closed-coil spring. Phosphate-buffered saline, immunoglobulin G (IgG) isotype control antibody, or anti-SDF-1 neutralizing monoclonal antibody were injected at the M1 and M2 interproximal areas (10 μg/0.1 mL) for the first three days. Analyses were performed after 1, 3, and 7 days (n = 7). The results demonstrated a significant increase in SDF-1 expression from day 1, which was effectively blocked via anti-SDF-1 neutralizing monoclonal antibody injection. On day 3, the M2 OTM distance and the number of positively stained osteoclasts significantly reduced alongside a reduction in inflammatory markers in the experimental group. Our results demonstrated that serial local injection of the anti-SDF-1 neutralizing monoclonal antibody reduces M2 OTM, osteoclast accumulation, and localized inflammatory responses in an OTM model with tooth extraction-induced RAP.

Effects of intracerebral noradrenaline on cognitive decline associated with the loss of occlusal support.

The lack of occlusal support reportedly reduces cognitive function; however, the underlying mechanisms remain unclear. The locus coeruleus, which is located adjacent to the trigeminal mesencephalic nucleus, secretes noradrenaline throughout the brain. In this study, we evaluated the effects of noradrenaline in the hippocampus and cerebral cortex on cognitive decline following tooth extraction in rats. We performed passive avoidance experiments on male Wistar rats with extracted maxillary molars and determined the neuron density in the locus coeruleus and trigeminal mesencephalic nucleus using immunostaining and Nissl staining, respectively. We also assessed noradrenaline concentrations in the hippocampus and cerebral cortex using enzyme-linked immunosorbent assay. In the passive avoidance experiment, the latency in the bright compartment was significantly shorter (P < 0.05) in the extraction group than in the control group. The numbers of cells in the locus coeruleus and trigeminal nucleus were significantly lower (P < 0.05) in the extraction group compared to those in the control group. The noradrenaline levels in the hippocampus and cerebral cortex were also significantly lower (P < 0.05) in the extraction group than those in the control group. The lack of occlusal support associated with tooth extraction reduces the number of cells in the trigeminal mesencephalic nucleus and locus coeruleus, which may reduce the supply of noradrenaline to the cerebral cortex and hippocampus, leading to a decline in cognitive function.

Prevention of Medication-Related Osteonecrosis of the Jaw by Local Application of Atelocollagen Containing a Hydroxymethylglutaryl-CoA Reductase Inhibitor to the MRONJ Model Rat Tooth Extraction Socket

Prevention of Medication-Related Osteonecrosis of the Jaw by Local Application of Atelocollagen Containing a Hydroxymethylglutaryl-CoA Reductase Inhibitor to the MRONJ Model Rat Tooth Extraction Socket

Effects of Photobiomodulation Therapy on Hard Tissue Healing in Rat Tooth Extraction Sockets.

Objective: To investigate the effects of photobiomodulation therapy (PBMT) on hard tissue healing in rat maxillary first molar extraction sockets. Methods: A total of 20 male Wistar rats were used in the study. The right extraction sockets were irradiated with a Ga-Al-As laser (500 mW, 980 nm) for 51.7 J/cm2 every 24 h for 7 days, while the left sockets served as controls. Rats were sacrificed on days 3, 7, 14, and 28 after tooth extraction, and microcomputed tomography (CT) analysis, histopathological evaluation, and enzyme-linked immunosorbent assay (ELISA) were conducted at different time points. Results: Micro-CT analysis showed that the percentage of bone volume/tissue volume (TV) and bone mineral density were significantly higher in the experimental group compared to the control group on day 28 (p < 0.05). Histopathological evaluation revealed that PBMT promoted new bone formation and accelerated bone remodeling. ELISA demonstrated a significant increase in alkaline phosphatase expression in the laser sides on days 7 and 14 (p < 0.05). Conclusions: One application postextraction followed by seven consecutive daily applications of PBMT can effectively promote hard tissue healing in rat maxillary first molar extraction sockets.

Hydroxyapatite/calcium alginate composite particles for hemostasis and alveolar bone regeneration in tooth extraction wounds

Tooth extractions can lead to complications such as post-extraction bleeding and bone resorption, which may result in unfavorable outcomes for implant restoration afterwards. To strive for an optimal condition for further restoration procedures, appropriate strategies, such as hemostasis or bone regeneration, are encouraged to be employed. However, the existing products are failed to meet both needs. As a widely employed tissue engineering materials, hydroxyapatite and calcium alginate both have demonstrated excellent performance in osteogenesis. However, their inferior mechanical strength poses a major limitation to their use in supporting the contracted extraction socket, which can easily lead to alveolar crest atrophy and barely achieve satisfying results. Calcium alginate improves the mechanical strength of hydroxyapatite, enabling the formation of new bone tissue and degradable in vivo. In this study, we demonstrated the biocompatibility and haemostatic ability of nCA particles on a rat tooth extraction model. In addition, long-term observation has revealed minimal inflammation and bone tissue regeneration. Our findings suggest a promising insight for clinical applications in hemostasis and bone regeneration after tooth extraction.

Effect of Intermittent Hypobaric Hypoxia Exposure on HIF-1α, VEGF, and Angiogenesis in the Healing Process of Post-Tooth Extraction Sockets in Rats.

The aim of this study was to investigate the effect of intermittent hypobaric hypoxia (IHH) exposure on the expression of hypoxia-induced factor-1α (HIF-1α) messenger RNA (mRNA), vascular endothelial growth factor-a (VEGF-a) mRNA, and angiogenesis after tooth extraction in rats. On 45 male Sprague-Dawley rats were performed the removal of the maxillary left first molar, and then they were randomly divided into 9 groups, namely: 4 groups that were exposed to IHH for 30 minutes every day in the Hypobaric Chamber at an altitude of 18,000 feet, with 1 time hypobaric hypoxia (HH), 3 times HH, 5 times HH, and 7 times HH; 4 normoxia groups that were terminated on days 1, 3, 5, and 7 after tooth extraction; and the 1 control group. Real-time polymerase chain reaction measured the molecular changes in the socket tissue after tooth extraction in rats to evaluate the expression of HIF-1α mRNA and VEGF mRNA. Histological changes with hematoxylin and eosin staining were noted to evaluate the amount of angiogenesis in the socket after tooth extraction. Molecular and histological parameters were calculated at the end of each experiment on days 0, 1, 3, 5, and 7 after tooth extraction, which exhibited the improvement phase of the wound-healing process. Increases in the expression of HIF-1α mRNA, VEGF mRNA, and angiogenesis were found in the IHH group compared with the normoxia group and the control group. The expression of HIF-1α mRNA increased significantly (p < 0.05) in the group after one time HH exposure on day 1, then decreased in the IHH group (three times HH exposure, five times HH exposure, and seven times HH exposure) approaching the control group. The expression of VEGF mRNA and angiogenesis began to increase after one time HH exposure on day 1, and increased again after three times HH exposure on day 3, then increased even more after five times HH exposure on day 5, and increased very significantly (**p < 0.05) after seven times HH exposure on day 7. It showed that repeated or intermittent exposure to HH conditions induced a protective response that made cells adapt under hypoxia conditions. IHH exposure accelerates the socket healing of post-tooth extraction, which is proven by changes in HIF-1α mRNA expression and increase in VEGF mRNA expression as stimuli for angiogenesis in post-tooth extraction sockets under hypobaric hypoxic condition, which also stimulates the formation of new blood vessels, thereby increasing blood supply and accelerating wound healing.

Alveolar ridge preservation in rat tooth extraction model by chitosan-derived epigenetic modulation scaffold.

Alveolar ridge preservation is a surgical technique used to prevent dimensional changes in the alveolar bone by dressing biomaterials in the extraction socket. Recently, a chitosan biphasic calcium phosphate loaded with trichostatin A (CS/BCP/TSA) scaffold was introduced as an excellent bone-regeneration material. This study aimed to explore the biological properties of released trichostatin A (TSA) and evaluate the potential of the CS/BCP/TSA scaffold in preserving the alveolar ridge in a rat tooth extraction model. In vitro biocompatibility, histone deacetylase (HDAC) activity, and osteogenic differentiation of MC3T3-E1 cells were tested. For in vivo studies, the maxillary first molars (M1) of Wistar rats were extracted, and alveolar ridge preservation was performed using a CS/BCP/TSA scaffold or commercial bone graft. Micro-Computed Tomography (micro-CT), polyfluorochrome labeling, and histological analysis were used to evaluate the ridge-preservation ability. The released TSA was cytocompatible. Inhibition of histone deacetylase (HDAC) activity and induction of osteogenic differentiation in MC3T3-E1 cells were confirmed. The socket dressing with the CS/BCP/TSA scaffold showed increased socket bone fill and preserved the buccal and middle aspects of the alveolar ridge compared with the conventional graft. Further analysis of the bone regeneration ability by histomorphometric and histological analyses demonstrated that CS/BCP/TSA showed a significantly higher potential to induce bone formation and complete healing in the extraction socket than the other groups. The CS/BCP/TSA scaffold is a novel candidate for alveolar ridge preservation.

Denervation delays initialbone healing of rat tooth extraction socket.

Functions of nerves on bone has been a subject of intense research. The aim of this study is to observe initial bonehealing of rat tooth extraction socket after inferior alveolar nerve transection. The bilateral mandible second molars of eighteen Wistar rats were extracted in the study. The rats also suffered from right inferior alveolar nerve transection simultaneously (D + E group), only extraction as control (E group). One, two and four weeks after extraction, the mandibles were taken out for histological observation, TRAP staining, immunofluorescence, immunohistochemistry and micro-computed tomography (Micro-CT). Mouse bone marrow derived macrophages (BMMs) were cultured in vitro. Expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) were detected in vivo and vitro. The alveolar sockets had been filled to a large extent with new bone at 4 weeks, but BV/TV and BMD decreased in the D + E group. Accordingly, Expressions of osteocalcin (OCN) and osteopontin (OPN) were down-regulated in the D + E group. Denervation increased TRAP-positive osteoclasts and decreased expressions of Nrf2 at 2 weeks after extraction. Decreased Nrf2 promoted osteoclast differentiation of BMMs in vitro. Denervation delays initialbone healing of rat tooth extraction socket. Osteoclast activation induced by decreased Nrf2 might participated in the process.

Effectiveness of antimicrobial photodynamic therapy mediated by butyl toluidine blue in preventing medication-related osteonecrosis of the jaws in rats

BackgroundMedication-related osteonecrosis of the jaws (MRONJ) is difficult to treat, therefore, prevention would be the ideal clinical approach. This study evaluated the effectiveness of antimicrobial photodynamic therapy (aPDT), mediated by butyl toluidine blue (BuTB) in the prevention of MRONJ-like lesions after tooth extraction in rats. MethodsTwenty-eight senescent female rats were distributed in groups: VEH and VEH-aPDT, treated with vehicle, ZOL and ZOL-aPDT, treated with 100 µg/Kg of zoledronate, both treatments every three days over seven weeks. After three weeks from the commencement of treatment, the mandibular first molar was extracted. For the VEH and ZOL groups, no local treatment was performed, while with the VEH-aPDT and ZOL-aPDT groups, photodynamic treatment was carried out at 0, 2, and 4 days after extraction. For aPDT, 500μl of BuTB solution was deposited on the dental extraction site (0.5 mg/ml; 60 s), followed by irradiation with low-level laser (InGaAIP; 660 nm; 35 mW; 74.2 J/cm²; 60 s). After 28 postoperative days, euthanasia was performed. The hemimandibles were processed to: (1) histological analysis of tissue repair; (2) histometric analysis of the percentage of newly formed bone tissue (PNFBT) and percentage of non-vital bone tissue (PNVBT); (3) immunohistochemical analysis for tartrate-resistant acid phosphatase (TRAP). ResultsThe ZOL and ZOL-aPDT groups showed less TRAP-positive cells when compared with VEH and VEH-aPDT. The ZOL group demonstrated great compromise in the tissue repair process, consistent with MRONJ-like lesions. VEH, VEH-aPDT and ZOL-aPDT presented a favorable tissue repair process. PNFBT in the ZOL group was lower than in the VEH, VEH-aPDT and ZOL-aPDT groups, whereas PNVBT in the ZOL group was higher than in the VEH, VEH-aPDT and ZOL-aPDT groups. Conclusion: aPDT mediated by BuTB prevented the occurrence of MRONJ-like lesions after tooth extraction in rats.

A single session of antimicrobial photodynamic therapy does not influence the alveolar repair process in rats.

The aim of this study was to use microscopic and molecular techniques to evaluate the effects of a single session of antimicrobial photodynamic therapy (aPDT) on the alveolar repair process after tooth extraction in rats. The study sample included 84 rats divided into four groups, as follows: a) Control - untreated socket; b) Laser - socket treated using photobiomodulation; c) TBO - socket treated with topic application of the photosensitizer agent, toluidine blue O (TBO); and d) aPDT - socket treated with TBO and laser irradiation. An additional rat was used for thermal mapping during socket irradiation. The animals were euthanatized at 6, 15, and 28 days after unilateral extraction of the upper incisor. Quantitative and qualitative analyses of the connective and bone tissues, blood clot, blood vessel, and inflammatory infiltrate were performed, and real-time polymerase chain reaction was used to study the expression of genes (collagen type I, osteocalcin, alkaline phosphatase [ALP], runt-related transcription factor 2 [RUNX2], and vascular endothelial growth factor [VEGF]) involved in the bone healing process. No statistically significant differences in microscopic and molecular outcomes were observed between the groups (p > 0.05). A positive correlation was seen to exist between blood clot and VEGF (p = 0.000), and a negative correlation was observed between bone tissue and ALP (p = 0.028) and blood vessel and VEGF (p = 0.018). A single session of aPDT in the dental extraction site did not influence the alveolar repair process in rats.

Space-making effect for new bone formation by suppressing scar contraction of mucosal epithelium of rat tooth extraction wound using diode laser and CO2 laser treatment

Background/purposeAs an extraction wound closes, the mucosal epithelium of the tooth extraction wound impedes the space for new bone formation by invading into the extraction socket. Thus, the height of the alveolar crest decreases, causing significant depression of the alveolar mucosa. In this study, we created a rat tooth extraction model and examined the effects of laser irradiation by CO2 and diode on the dynamics of myofibroblast expression through α-SMA, and TGF-β1. Materials and methodsAfter tooth extraction of five-week-old male Wistar rats, they were divided into two laser treatment groups (CO2 laser or diode laser was irradiated into tooth extraction socket) and non-laser treatment group (control group). Surrounding tissues, including the extraction socket, were removed at 3, 5, 7, and 21 days after tooth extraction and the expression of α-SMA and TGF-β1 was verified using immunohistological techniques (6 animals in each group and each period, 72 animals in total). Resultsα-SMA-positive cells and TGF-β1-positive areas were significantly lower in the two laser treatment groups than in the control group. Particularly, the diode group almost had no TGF-β1-positive areas on the 21st day when healing after tooth extraction was deemed to be completed. ConclusionBoth CO2 and diode laser irradiation of tooth extraction wounds decreases α-SMA-positive cells and TGF-β1-positive areas. Further, it causes a decrease in myofibroblast expression and suppresses the invasion of mucosal epithelium into the extraction socket. Therefore, laser irradiation may exert a space-making effect for new bone formation and also contribute to socket preservation.

Assessment of cell phone effect on dental socket healing in rat.

Electromagnetic waves can cause biological effects on repair process. Due to the proximity of the jawbone and the soft tissue around it in a part of the face with which it has the closest contact during the cell phone use, this study aims to investigate the effect of mobile waves on socket healing after tooth extraction in rats. This experimental study was conducted on 32 rats. The case group was exposed to a 900 MHz frequency electromagnetic field for 30 min/d. Sacrificed eight rats from the case group and 7 rats from the control group on day 14, and 8 rats from the case group and 7 rats from the control group were sacrificed on day 28 at the end of the radiation period and CBCT and microscopic examinations on the maxillary bones and soft tissue were performed. According to the findings, the healing process was significantly different in two groups in terms of the percentage of new bone formation on day 14 after the end of radiation (P=0.014). The other measured parameters including the degree of inflammation, thickness of the formed bone, number of osteoblasts and Gray Scale had no significant difference between the two groups in any of the 14-day and 28-day intervals. The results of this study showed that intermittent exposure to high frequency electromagnetic fields over a period of 20 hours has no significant effect on the healing process of alveolar socket after tooth extraction in rats.

Effects of the prevention of medication-related osteonecrosis of the jaw by local administration of a dental pulp stem cell-conditioned medium to the rat tooth extraction socket.

The onset of osteonecrosis of the jaw, which is a side effect of bisphosphonates, often develops after tooth extraction; measures for its prevention have not yet been established. While treatment with systemic administration of bone marrow stem cell-derived conditioned medium for medication-related osteonecrosis of the jaw (MRONJ) has been reported, its preventive effects have not been clarified yet, and the high degree of invasiveness of bone marrow fluid collection remains an issue. Therefore, we created a rat model of MRONJ using BP zoledronic acid, used a dental pulp stem cell-conditioned medium (DPSC-CM), which can be collected relatively easily, and locally applied it to the tooth extraction socket with atelocollagen and gelatin sponges. The preventive effect on the onset of MRONJ was subsequently examined. The results demonstrated that the bone exposure width of the extraction socket was reduced, and the mucosal covering was promoted in the atelocollagen + DPSC-CM group as compared with the other groups. Furthermore, histological results indicated a decrease in the number of empty bone lacunae, whereas immunohistochemical staining revealed the presence of many vascular endothelial growth factor (VEGF)-positive cells. Moreover, the results of the investigation of the sustained release of atelocollagen using VEGF indicated the release of VEGF over time. Our results suggest that local administration of DPSC-CM using atelocollagen may be a useful method for the prevention of MRONJ triggered by tooth extraction.

Potential Effect of Djambal Catfish (Pangasius djambal) Gelatin as Biomaterial Product on Healing Socket after Tooth Extraction in Rats

Purpose: Adequate wound healing after a tooth extraction is significant because the oral cavity has amasticatory function and plays a role in nutrient intake. Various scientific studies have been conducted tofind the ideal biomaterial to support wound healing. This study aims to determine the wound healing activityusing Djambal Catfish (Pangasius djambal) gelatin after tooth extraction.Method: Gelatin was obtained from Djambal Catfish (Pangasius djambal). The sample was selected byrandom sampling, divided into 6 groups, namely the control group on the 3rd day (n=6), the control groupon the 5th day (n=6), the control group on the 7th day (n=6), the treatment group on the 3rd day (n=6), thetreatment group on the 5th day (n=6), and the treatment on the 7th day (n=6). Wound healing was examinedby evaluating wound healing marker such as macrophages, fibroblasts, epithelialization, angiogenesis, andcollagen. Data were processed using statistical analysis.Results: The treatments had a positive result in wound healing as compared with the control groups.Histological assessment showed a remarkable sign of an increased number of macrophage, fibroblast,epithelialization, and collagen deposition.Conclusion: Gelatin derived from Djambal Catfish (Pangasius djambal) can accelerate the wound healingprocess thus could be a component therapeutic potential product that may be beneficial in wound healing inthe future.

Endoplasmic reticulum stress remodels alveolar bone formation after tooth extraction.

Bone healing in tooth extraction sockets occurs in a complex environment containing saliva and many microorganisms and is affected by many factors. Endoplasmic reticulum (ER) stress affects bone metabolism, but the role of ER stress in bone healing after tooth extraction remains unclear. We utilized a rat tooth extraction model, in which we promoted wound healing by using salubrinal to regulate the ER stress response. Western blot analysis showed increased expression of p‐eIF2α/eIF2α, Runx2 and alkaline phosphatase (ALP) in bone tissue, and histological assays showed irregularly arranged and new bone with more collagen fibres 14 days after tooth extraction and after modulating the degree of ER stress. Micro‐CT showed that modulating ER stress to an appropriate degree increases bone filling in regards to the density in the bottom and the surrounding bone wall of the tooth extraction wounds. Transmission electron microscopy showed rough ER expansion and newly formed collagen fibrils in osteoblasts after modulating ER stress to an appropriate degree. We also used different concentrations of salubrinal to evaluate the resistance to tunicamycin‐induced ER stress in an osteogenic induction environment. Salubrinal restored the tunicamycin‐induced decrease in the viability of primary calvarial osteoblasts and increased the expression of Runx2 and ALP, and decreased p‐eIF2α/eIF2α in a dose‐dependent manner. Taken together, the results demonstrate that ER stress occurred after tooth extraction, and regulating the degree of ER stress can promote bone healing in tooth extraction sockets, providing clinical evidence for bone healing.