Rat Tooth Research Articles

Notch signaling inhibition protects against root resorption in experimental immature tooth movement in rats

This study aimed to build an experimental immature tooth movement model and verify less resorption of incompletely developed roots than those fully developed during the same orthodontic treatment, followed by investigating the cellular and molecular mechanism. The development of Wistar rat tooth was investigated using invivo microcomputed tomography and hematoxylin and eosin staining to decide the optimal ages of rats for immature tooth and mature tooth groups. The rats in the immature tooth and mature tooth groups were divided into experimental, sham control, and blank control groups. After orthodontic treatment for 3weeks, the mesial root volume, crown movement distance, neck movement distance, root inclination, and apical distance were measured by microcomputed tomography. The expressions of TRAP, Jagged1, Notch2, IL-6, and RANKL were analyzed by immunohistochemical staining and real-time polymerase chain reaction. The repair of root resorption was also investigated after removing orthodontic force for 3 and 6weeks. The root achieved the development stage around 10weeks, so 4-week-old rats and 10-week-old rats were used in the immature tooth group and mature tooth group, respectively. The volume of root resorption in the experimental immature tooth group was 0.0869±0.0244mm3, which was less than that in the mature tooth group (0.1218±0.0123mm3)(P<0.001). Immature tooth movement decreased TRAP-positive odontoclasts on the compression side while having no statistically significant effect on osteoclasts. The protein expression of Jagged1, Notch2, IL-6, and RANKL in the mature tooth group increased significantly compared with the immature tooth group, not only on the compression side but also on the tension sides. The mRNA expression of Jagged1, Notch2, and RANKL was significantly lower in the immature tooth group, whereas the expression of IL-6 had no significance but a strong tendency. The root volume after repairing for 3weeks was still less than that of blank control, whereas after repairing for 6weeks, the difference was not statistically significant. The experimental immature tooth movement model for the Wistar rat was achieved for the first time. The immature tooth will suffer less root resorption than the mature tooth, which may be due to odontoclastogenesis inhibition by decreased expression of Jagged1/Notch2/IL-6/RANKL signaling.

The use of carbonate apatite bioglass cement as pulp capping material examined from reparative dentin

Root canal infection potentially develops to periapical infection as a result of opening of pulp chamber as a pathway for irritants to periapical area. Proper pulp capping procedure can be done to prevent root canal infection by preserving the vitality of the pulp and inducing reparative dentin. Generally, calcium hydroxide (Ca(OH2)) is used as pulp capping material although it stil3Ap) and CO3Ap bioglass cement are bioceramic materials proven for their ability to form new bone structure upon a research on bone tissue. These materials have better mechanical strength than Ca(OH2) and have the ability to set in humid environment similar to the body’s physiological condition. This study was a preclinical trial of CO3Ap and CO3Ap bioglass cement as pulp capping material. The materials were applied on a perforation site of 24 Wistar rat teeth, divided into 4 groups of different treatments, negative control (no treatment), positive control (Ca(OH2)), CO3Ap, and CO3Ap bioglass, respectively. Following the application of the pulp capping materials, the perforation sites were covered with light-cured glass ionomer cement. Evaluation of reparative dentin was performed after 21 days, where the rats were euthanized, and histopathological specimens were stained using hematoxylin and eosin. The results of the study revealed that dentinal bridge was formed on all the treatment and positive control groups (p=0.000) but not on the negative control. We concluded that CO3Ap as well as CO3Ap bioglass cement have the ability to induce the formation of reparative dentin, therefore both materials can be considered as pulp capping material for open pulp or thin dentin condition on pulp chamber roof.

Cellular Toxicity Mechanisms of TiCN-Cp-Ti Screw on Tooth Gum Cells in Rat

Cellular toxicity mechanism of TiCN film deposited on Cp-Ti substrate by Cathodic Arc Physical Vapor Deposition (CAPVD) method has yet to be clarified. The present study is aimed at finding out the possible effects of synthesized TiCN on the isolated tooth gum cells and realizing its cytotoxicity mechanism under experimental conditions compared to that of Au screws (standard in medicine). Results of the XRD analysis showed that TiCN film was formed in coating. The SEM image of TiCN film displayed a rough and irregular morphology and fine-grained surface. In addition, some other features such as cell viability, the level of Reactive Oxygen Species (ROS), lipid peroxidation (MDA), Glutathione Count (GSH and GSSG), Adenosine Triphosphate (ATP) were examined. On the other hand, activity of succinate dehydrogenase (complex II), NADH dehydrogenase (complex I), Coenzyme Q-cytochrome c reductase/Cytochrome b (complex III) and cytochrome c oxidase (complex IV) were also determined. Finally, it was also determined that level of Alkaline Phosphatase (ALP), Aspartate Amino Transferase (AST), Alanine Aminotransferase (ALP), Urea, Creatinine Clearance (CR) in rat (tooth gum cells) could also change. The results of the study revealed that TiCN coating did not incur an extremely change on cellular toxicity biomarker compared to Au standard screw in animal study. Our study provides the first evidence that TiCN coating is a biocompatible material in the cell. This paper suggests that the use of the TiCN in human dental applications need further examinations in a wide range of cellular-death signaling.

The Effects of Immunosuppressive Treatment during Pregnancy on the Levels of Potassium, Iron, Chromium, Zinc, Aluminum, Sodium and Molybdenum in Hard Tissues of Female Rats and Their Offspring.

The ideal immunosuppressive regimen should provide for excellent immunosuppression with no side effects. Yet, current immunosuppressive therapy regimens commonly used in clinical applications fail to meet this criterion. One of the complications caused by immunosuppressive drugs is mineralization disorders in hard tissues. In this study, we evaluated the effects of three immunosuppressive therapies used after transplantation on the levels of potassium, iron, chromium, zinc, aluminum, sodium and molybdenum in the bones and teeth of female rats and their offspring. The study was conducted on 32 female Wistar rats, subjected to immunosuppressive regimens (cyclosporine A, mycophenolate mofetil and prednisone; tacrolimus, mycophenolate mofetil and prednisone; and cyclosporine A, everolimus and prednisone). The hard tissues of rats were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES, ICAP 7400 Duo, Thermo Scientific) equipped with a concentric nebulizer and a cyclonic spray chamber. All the immunosuppressive regimens included in the study affected the concentrations of the studied minerals in hard tissues of female rats and their offspring. The therapy based on cyclosporine A, everolimus and prednisone led to a decline in the levels of iron in bone, zinc in teeth, and molybdenum in the bone and teeth of mothers, while in the offspring, it caused a decline of bone potassium, with a decrease in iron and increase of molybdenum in teeth. Moreover, the regimen caused an increase in aluminum and chromium in the teeth and aluminum in the bones of the offspring, and consequently, it seems to be the therapy with the most negative impact on the mineral metabolism in hard tissues.

Comparative evaluation of pulpal repair after direct pulp capping using stem cell therapy and biodentine: An animal study.

The response of the dentin-pulp complex in rat teeth was investigated after direct capping with biodentine with or without bone marrow-derived stem cells (BMDSCs). Following mechanical exposure, pulps were randomly capped with one of the followings materials: calcium hydroxide, biodentine or 1×105 BMDSCs mL-1 + biodentine. Histological examination was performed by light microscopy after 1, 3 and 5weeks. Inflammatory reaction, necrotic tissue formation and calcific bridge formation were scored. Analysis showed that compared with the effects of calcium hydroxide or biodentine, BMDSCs+biodentine substantially reduced inflammatory reaction and necrotic tissue while promoting calcified tissue formation. Therefore, the combination of biodentine and BMDSCs could potentially stimulate pulp tissue regeneration after direct pulp capping.

S2326 Grasping for Straws: A Rare and Challenging Complication of Biliary Stenting

INTRODUCTION: Proximal (cephalad) migration of a biliary stent (PMBS) may be associated with severe complications. Prompt recognition and retrieval is important, but may be quite difficult. We present a challenging case of proximal migration of a plastic CBD stent, highlighting techniques used for successful retrieval. CASE DESCRIPTION/METHODS: A 73-year-old F with an indeterminate proximal CBD and common hepatic duct (CHD) stricture undergoing biliary endotherapy presented for a scheduled ERCP. Due to inadequate drainage via retrograde approach, a percutaneous biliary drain (PBD) was placed 9 months ago and patient had undergone multiple biliary drain exchanges and one liver biopsy. Surgical resection was not pursued due to underlying comorbidities. Two weeks prior to presentation, ERCP for internalization of PBD revealed that a previously placed 7Fr x 12cm straight plastic stent had migrated proximally within the anterior RHD (Figure 1). Attempts to retrieve the migrated stent with balloon and snare were unsuccessful, so a 10Fr x 10cm stent was placed and PBD was pulled. On repeat ERCP, direct visualization with Spyglass cholangioscopy revealed the stent to be embedded within the bile duct sidewall at the stricture level (Figure 2). Multiple tools, including balloon catheter, snare and pediatric biopsy forceps failed to remove the stent. Even the cholangioscope biopsy forceps could not grasp stent sufficiently to enable traction and removal. After multiple failed attempts, the stent was successfully retrieved using a small rat tooth forceps via direct grasping of its distal end within the CHD under fluoroscopy. Repeat cholangiogram showed stable findings and no perforation and a 10Fr x 12cm straight plastic stent was replaced. DISCUSSION: PMBS is rare and endoscopic retrieval can be challenging. Risk factors of PMBS include malignant stricture, large stent diameter and shorter stent length. Retrieval of PMBS is critical to avoid complications such as hepatic/ductal perforation and fistula. Endoscopic retrieval methods include Soehendra retriever, basket, lasso technique, balloon and forceps. Cholangioscopy can also be used but was not helpful in this case. Fluoroscopic positioning of rat tooth forceps enabled stent retrieval in our case. We postulate that multiple biliary drain exchanges may have caused proximal migration of the biliary stent. Knowledge of the various tools and techniques to retrieve proximally migrated biliary stents is essential to successfully manage these technically challenging cases.Figure 1.: Fluoroscopic visualization of proximally migrated straight biliary stent appearing as an upside down “V”.Figure 2.: Direct visualization of the embedded distal end of the proximally migrated straight biliary stent using Spyglass cholangioscopy.

S2322 Utilization of Endoluminal Vacuum Therapy for a Challenging Lesser Curve Leak

INTRODUCTION: Anastomotic leaks can occur in up to 15% of patients undergoing esophagectomy with gastric pull-up. Endoluminal vacuum therapy has become a well-documented technique to treat perforations and anastomotic leaks; however, technical success can vary. We present a case of a lesser curve anastomotic leak after esophagectomy that developed into a large cavity requiring unique techniques for successful endoluminal vacuum therapy. CASE DESCRIPTION/METHODS: A 66-year old male with esophageal adenocarcinoma underwent an Ivor Lewis esophagectomy. On day 20, a CT scan to investigate abdominal pain revealed a lesser curvature staple line leak resulting in an empyema (Figure 1). Chest drainage was performed and a pigtail catheter was maintained to gravity. An EGD was performed given persistent drain output and revealed a 4-cm linear defect into the pleural cavity with substantial debris (Figure 2). Given the size and location, endoluminal vacuum therapy was planned. A 16 Fr nasogastric tube (NGT) was passed nasal to oral and a wound vac sponge was sutured with 3-0 silk to the tip. This was subsequently advanced into the gastric defect and chest cavity and placed to vacuum suction. Given the angulation, a biliary wire was used to maintain visualization. To insert a larger-sized sponge into the cavity, a double-channeled gastroscope was used to simultaneously manipulate two rat tooth forceps. Once a shallow, smaller defect was present, the NGT was transitioned to a 10-mm Jackson-Pratt (JP) silicone flat drain, allowing for easier sponge placement and better approximation. Strict nil per os, antacid therapy, and pigtail chest drainage to bulb suction were key to keep the cavity dry. After 13 exchanges, the defect appeared closed as confirmed with fluoroscopy (Figure 3). DISCUSSION: Endoluminal vacuum therapy is an effective therapy to treat anastomotic leaks after esophagectomy. Several characteristics can alter technical success, and in our case, the angulation at the cavity inlet, linear nature of cavity, and drain management presented challenges. An endoscopically placed wire can be used to maintain visualization of a defect and the use of two rat tooth forceps through a double-channeled gastroscope allows for easier manipulation of the sponge. Bulb suction should be applied to cavity drains for an ideal vacuum effect. The shape and fenestrations of a JP flat drain allow for better positioning into linear defects as they become smaller and apply an evenly distributed gentle vacuum effect.Figure 1.: CT imaging with lesser curvature staple line leak resulting in right posterior pleural space empyema (yellow box).Figure 2.: Initial EGD demonstrating the inlet of the defect (left, black oval) and deep linear cavity (right).Figure 3.: Endoscopic (left, black oval) and fluoroscopy image (right) confirming defect resolution.

S2328 A Tale of Two Perfs: Successful Repair of Dual Iatrogenic Duodenal Perforations Through Endoscopic Stenting

INTRODUCTION: Duodenal perforations are rare but serious gastrointestinal injuries, which pose challenging management decisions dependent on their etiology.[1,2] We report the use of a fully-covered self-expanding metal stent (FC-SEMS) for the management of iatrogenic duodenal perforations, which resulted in successful healing of perforations albeit associated with delayed morbidity from stent migration. CASE DESCRIPTION/METHODS: A 33 year-old male was admitted following a major motor vehicle collision with severe intraabdominal injuries requiring multiple surgeries, leading to the development of intra-abdominal infection requiring percutaneous drainage of RUQ and midabdominal fluid collections. Eight weeks after drain placement, enteral feeds were initiated with upper GI series confirming an active duodenal leak (Figure 1A). Endoscopic intervention was pursued due to high operative risk and demonstrated evidence of lateral and medial duodenal perforations secondary to erosions from the percutaneous RUQ drain (Figures 2A and 2B). The duodenal perforations were successfully stented using a FC-SEMS (18 mm × 12 cm) and sutured in place with an over-the-scope suturing system (Figures 1B and 1C). Enteral feeds were reinitiated with a small but stable leak, and the patient was discharged 12 weeks later. Eight weeks after discharge, the patient was readmitted for soft tissue infection from a colocutaneous fistula from prior bowel surgery, however CT scan also showed stent migration into the jejunum (Figure 3A) with a stable duodenal leak. Single balloon enteroscopy was performed with removal of the stent facilitated by pulling the stent into the cap with rat tooth forceps and using the splinting tube as an overtube to minimize bowel injury during withdrawal. Final endoscopic visualization revealed complete healing of the peritoneal fistula and near-complete healing of the retroperitoneal fistula (Figures 2C and 2D). DISCUSSION: The use of SEMS for the management of duodenal perforations has previously been reported, although predominately in the treatment of malignant gastric outlet obstruction or biliary stent complications and with limited patient follow up data.[3–6] Our case illustrates the successful use of a FC-SEMS for healing of dual duodenal perforations in a patient whose level of illness precluded medical or surgical management. Our case also highlights the risk of stent related complications such as delayed stent migration which can be difficult to manage, in particular outside centers of expertise.Figure 1.: Figure 3A: Upper GI series showing medical (circle) and lateral contrast leakage (arrow) Figure 1B: Duodenal stent in place with contrast injection showing minimal leak Figure 1C: Stent sutured in place in the gastric antrum.Figure 2.: Figure 2A: Pigtail drain in duodenum (*) and peritoneal fistula (^) Figure 2B: Visible retroperitoneal drain (*) in retroperitoneal fistula after RUQ drain repositioned Figure 2C: Duodenal lumen 20 weeks following stent placement without evidence of peritoneal fistula Figure 2D: Healing retroperitoneal fistula, approximately 1-2 mm in diameter.Figure 3.: Figure 3A: Stent migration into the jejunum, 20 weeks after placement Figure 3B: Endoscopic view of jejunal stent including endoscopic sutures (*) Figure 3C: Stent following removal.

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.

Radiographic and Histologic Evaluation of Experimentally Induced Severe Intrusive Luxation of Immature Teeth in Rats

IntroductionThe aim of this study was to establish an intrusive luxation model in rats and observe the pulpal and periodontal outcomes. MethodsThe intrusion was experimentally induced by an application of 20-N force on the occlusal surface of maxillary right second molar along the tooth axial using a striking instrument in 3-week-old male Sprague-Dawley rats. Thirty rats were divided into 6 groups (n = 5) and were sacrificed after 3, 7, 14, 30, 60, and 90 days of the surgery. The occurrence of pulpal and periodontal complications was observed by micro–computed tomographic scanning and hematoxylin-eosin staining. ResultsAll experimental teeth were fully intruded into the alveolar bone with their occlusal surface located at the cervical level of the adjacent first molar. Spontaneous re-eruption initiated at 7 days. At 14 days, 4 teeth (80%, 4/5) partially re-erupted, whereas 2 (40%), 3 (75%), and 4 (100%) teeth completely re-erupted at 30, 60, and 90 days, respectively. Pulp degeneration and inflammation mainly occurred in 4 teeth at 3 days, 5 at 7 days, and 2 at 14 days; after 14 days, pulp calcification was observed in 8 teeth. Ankylosis and replacement root resorption mainly occurred in 1 tooth at 30 days, 2 teeth at 60 days, and 3 at 90 days. Marginal bone loss was observed in 3 teeth (60%) at 30 days, 3 (75%) at 60 days, and 2 (50%) at 90 days. ConclusionsAn animal model of intrusive dentoalveolar trauma was successfully established in rats. Pulpal and periodontal complications similar to clinical tooth intrusion were observed, which provided a basis for exploring the mechanisms of complications in the future.

Effect of root surface treatment with denusomab after delayed tooth replantation.

To evaluate denosumab, a human monoclonal antibody that mimics the effects of osteoprotegerin in bone metabolism, as a topical treatment of root surface to be used prior to delayed tooth replantation. Thirty-six rats' right incisors were used. Teeth were extracted and divided into: delayed replantation without root surface treatment (control); delayed replantation with root surface treatment with denosumab 60mg/mL and 30mg/mL, respectively, for 10min both experimentals groups. After that, the root canals were filled with calcium hydroxide and replanted. After 15 and 60days, the animals were euthanized, and the samples were collected and processed for microscopic analysis. Histological sections were performed, and stained with HE to describe the dental characteristics, measure ankylosis, replacement resorption, and dental resorption by conventional microscopy. Also, was performed Brown & Brenn staining and immunohistochemistry for RANKL, OPG, and periostin. Denosumab 60mg/mL reducted ankylosis (p < 0.0001), replacement resorption (p < 0.0001), and tooth resorption, 60days after replantation, compared to untreated replanted teeth (p < 0.005). Lower bacterial contamination in root surface in the denosumab treatment groups was found, regardless of the concentration used (p < 0.001). Also, denosumab treatment inhibited the expression of RANKL without modulating OPG. Periostin was observed in periodontal ligament of replanted tooth, although this labelling was absent in the ankylosis areas, in both experimental periods. Treatment of the root surface with denosumab at 60mg/mL of rat teeth before delayed replantation reduced dental root resorption compared with the untreated teeth after 60days. Survival of a replanted tooth has been a challenge in clinical practice. The use of a medication, such as denosumab, to limit dental root resorption represents an important therapeutical approach.

Upper Gastrointestinal Foreign Body, our Experience in Faridpur Medical College Hospital

Accidental ingestion and impaction of food or non-food foreign body in upper GIT is not uncommon. This retrospective study was undertaken at Gastroenterology department of Faridpur Medical College Hospital, Bangladesh. Data were collected from endoscopy software by computer search among patients with foreign bodies in upper GIT from January 2012 to December 2018. Total 41 patients with endoscopically proved ingested with or without impacted foreign body in the upper GIT were studied. Of them, 28 were male and 13 were female with age ranges from 15 to 85 years with a mean age of 52.66 ± 19.7 years. Meat bolus was the commonest type (12; 29.3%), followed by dental prosthesis (9; 22%). Most of them (24; 58%) were impacted between 20 to 30 cm from incisor teeth. We could successfully remove 38 cases with a success rate of 92.7% with the help of dormia basket, polypectomy snare &amp; rat tooth foreign body grasper. We found few erosions and superficial ulcerations at the impacted site among patients with dental prosthesis, pill with strip and chicken bone. One patient with sharp flat bone of hilsa fish was impacted at esophagus like sharp cutting blade and produced incised looking wound at both esophageal walls. In 19 cases (46.34%) we found definite anatomic abnormalities and 19 cases (46.34%) no abnormalities was found. Rest 3 cases, who were referred to surgeon we failed to know the underlying pathology. Sharp foreign bodies impacted at upper esophagus were difficult to remove endoscopically. Faridpur Med. Coll. J. Jul 2019;14(2): 74-78

Retrieval of Aspirated Teeth in an Adult Polytrauma Patient using Pediatric Flexible Fiberoptic Bronchoscopy Allied with Endoscopic Rat Tooth Alligator Jaw Grasping Forceps

Foreign body (FB) aspiration in maxillofacial injuries is a life-threatening event. A long-time interval between the aspiration and retrieval results in the formation of granulation tissue and mucosal inflammation around the FB, which could restrict the visual field of bronchoscopy and its retrieval. In addition, it can affect the lung structure with fatal complications. Herein, we present a case of unique FB retrieval (2 joined crown teeth – measuring 19 mm) within 8 h following aspiration in a 24-year-old male polytrauma victim. Further, we discuss our successful modified retrieval technique accordingly without resulting in any complications.

Expression of fibroblast cells after extraction of wistar rat teeth after topical application of okra fruit (Abelmoschus esculentus) gel.

BackgroundTooth extraction is a dental procedure for removing a teeth from the alveolar bone socket. The tooth extraction process causes damage to hard tissue and soft tissue, so the body will respond physiologically to heal the wound. The wound healing process is divided into several phases, one of which is the proliferation phase of fibroblasts, which is one of the most important phases in the process of wound healing. Okra fruit contains saponins, tannins, flavonoids and alkaloids that have antiinflammatory, antibacterial, antioxidant effects, and can stimulate angiogenesis so to accelerate the process of wound healing.Objectiveto prove that the administration of okra fruit extract can accelerate the process of wound healing after extraction in the teeth of Wistar rats through increased expression of fibroblast cells.Methods18 Wistar rats were divided into 2 groups; control group and treatment group. The treatment group received a 30% okra fruit extract. The number of fibroblasts was calculated statistically using One Way ANOVA and Tukey HSD.ResultsThe results showed that the expression of control group fibroblast cells on day 3 (19.00±2.0), day 5 (21.67±2.08), day 7 (24.00±2.00), whereas in the treatment group on day 3 (24.00±1.00), day 5 (29.00±2.00), day 7 (30.00±1.53). Anova test between groups showed a significant difference with P-value 0.006.Conclusion30% okra fruit extract can increase fibroblast expression in wound healing process after extraction of Wistar rat teeth.

THE EFFECT OF CALCIUM HYDROXIDE-PROPOLIS ON THE NUMBER OF MACROFAG CELLS ON THE WISTAR RAT DENTAL WITH PULPA PERFORMANCE

Background: Cellular response of dental pulp to existing lesions, caused by infiltration of inflammatory cells that migrate from blood vessels to the site of injury. Macrophages are the cells that most appear when inflammation occurs. Treatment for maintaining pulp tissue vitality is called pulp capping. Calcium hydroxide as a pulp capping material has the ability to trigger the growth of dentin bridges or remineralization, but calcium hydroxide can induce migration and proliferation of inflammatory cells. Currently the field of dentistry is developing propolis as an alternative pulp capping material. That is because propolis has anti-inflammatory properties. Objective: To analyze the effect of the combination of calcium hydroxide-propolis on the number of macrophage cells in the teeth of wistar rats with pulp perforation. Method: This study used 30 samples of Wistar rats which were preparated until perforation and then divided into 3 groups. The first group continued with filling with cention, the second group continued with application of calcium hydroxide and filled with cention, and the third group continued with the application of combination of calcium hydroxide and propolis and then being filledwithcention. Macrophage cell is calculated histopathologically by using compound light microscope on the 3rd day with 400x magnification. Results: The Kruskal-Wallis test results showed significant differences in macrophages after the combination of calcium hydroxide and propolis (p = 0,000). The combined application of calcium hydroxide and propolis showed higher macrophages than the application of calcium hydroxide and the control group. Conclusion: Application of calcium hydroxide - propolis combination was proven increase the number of macrophage cells in Wistar Rats (Rattus Norvegicus) with pulp perforation

Effect of Hydrogel Epigallocatechin-3-Gallate (EGCG) to the Number of Fibroblast Cell Proliferation in the Perforation of Wistar Rat Tooth Pulp

Background: Pulpitis can occur because the deep cavity preparation and it causes increasing of NO levels. Perforated teeth require direct pulp capping (DPC) treatment. The current standard DPC material is calcium hydroxide. However, several studies have found weaknesses of calcium hydroxide that can affect the success of DPC treatment and new, more biocompatible materials are needed. Epigallocatechin-3-gallate (EGCG) in green tea has many benefits, including antioxidant, anticolagenase, anticancer, anti-inflammatory and has the ability of radical scavenging to clean NO so that pulp healing can occur better by increasing the number of fibroblast cells that play a role in wound healing. Purpose: To determine the concentration of hydrogel EGCGs that are effective in increasing the number of fibroblast cell proliferation in the dental pulp perforation of Wistar rats. Method: This research is a laboratory experimental study with a randomized post test only control group design. Samples used in the study were 24 male Wistar rats which were divided into four groups, namely the negative control group and the treatment group were given EGCG 60 ppm, 90 ppm, and 120 ppm and were decapitated on the 7th day after treatment. The maxilla and the 1st molar were taken and decalcified, to process the HPA reading with HE staining. Observations were made using a microscope with a magnification of 400x. Results: There were significant differences in the treatment groups with 60 ppm and 90 ppm hydrogel hydrogels on the results of the Oneway ANOVA difference test (p &lt;0.05). Conclusion: The concentration of hydrogel EGCG which is effective in increasing fibroblast cell proliferation is 90 ppm.

Disorders of microcirculation in the mechanism of bisphosphonate osteonecrosis: preliminary study in rats.

We investigated the possibilities of angioprotection and the reduction of osteonecrosis in rats that had been given bisphosphonates. In our experiment, 27 rats were divided into three groups: Group 1 was injected with saline; Group 2 was given zoledronic acid for six weeks; and Group 3 was given zoledronic acid for six weeks, with added doses of sulodexide after three weeks. After that we constructed a model of how the teeth should be extracted. The velocity of linear blood flow in the periodontal area of an extracted tooth in rats was studied using laser and high-frequency Doppler ultrasound (with the application of the vasoactive substance acetylcholine 3% for 1min). We evaluated changes in the structure of the bony tissues of the head using computed tomography, comparing the control group with the saline group. A rapid reduction in microcirculation was detected during the use of zoledronic acid for six weeks. A smaller reduction in microcirculation was detected after three weeks of treatment with sulodexide and zoledronic acid. There was a reduction in blood flow in the mucous membranes and, to a greater extent, in bony tissue. Zoledronic acid causes significant impairment of the periosteal blood flow to the mucous membranes because of a complex of disorders, which includes both the cellular component (impaired endothelium-dependent vasodilation of the mucous membrane vessels) and by reducing the intensity of microcirculation in the mucous membranes and bony tissues. Sulodexide, however, improves the restoration of blood flow and reduces the severity of osteonecrosis.

An algorithm for retrieval tools in foreign body ingestion and food impaction in children.

The aim of this study is to review the experience on managing foreign body ingestion in children with special emphasis on the endoscopic techniques and specific retrieval devices used for foreign body (FB) extraction. The charts of 341 children were reviewed retrospectively. Demographic data, ingested material, removal technique and tool, level of FB, complications, and outcomes were recorded. A total of 364 FBs were removed from 341 children. Among these, 56.5% (n: 206) were entrapped in esophagus, 39% (n: 142) were in stomach, and 4.5% (n: 16) in duodenum and intestine. The most frequently ingested items were coin (42.5%), button batteries (20.6%), and safety pins (12%). Optical forceps (37.9%) were the most commonly used tool and they were used during retrieval of esophageal FB by rigid endoscopy. Retrieval net (20.7%) was the second most common tool and the most common one during flexible endoscopy. Depending on our experience, we strongly advocate rigid endoscopy for esophageal FBs and food impaction in children because it allows both to use optical forceps with a strong grasping ability for blunt FBs and to position sharp and pointed objects inside the rigid endoscope. We recommend retrieval net as the first tool for the extraction of blunt objects and rat tooth retrieval forceps is the best tool for sharp and pointed FBs in stomach.

Influence of low-level laser therapy on inflammation, collagen fiber maturation, and tertiary dentin deposition in the pulp of bleached teeth.

We evaluated the effects of low-level laser therapy (LLLT) using an infrared laser (IRL) and a red laser (RL) on the pulp of molar teeth in rats after dental bleaching to assess inflammation, collagen fiber maturation, and tertiary dentin formation. Eighty Wistar rats (Rattus norvegicus, albinus) were randomly divided into eight groups with 10 hemimaxillae in each of the following: control; bleached (Ble, 35% hydrogen peroxide [H2O2]); Ble-1IRL and Ble-1RL (one IRL [808nm, 30s, 3J] or RL [660nm, 15s, 1.5J] application immediately after H2O2); Ble-3IRL and Ble-3RL (three [immediately, 24h, and 48h] IRL or RL applications after H2O2); and 3IRL and 3RL (three IRL or RL applications without bleaching). The rats were euthanized after 2 and 30days for histological evaluation of inflammation (hematoxylin-eosin) and maturation of collagen fibers (picrosirius red). Additionally, the dentin deposition in the specimens obtained at 30days was quantified via microtomography of the pulp chamber volume. Statistical analyses were performed (P < 0.05). Initially, severe damages to the pulp were observed in the Ble and Ble-1RL groups. Ble-1IRL and Ble-3RL groups showed lower inflammation. The bleached groups had a greater amount of mature collagen fibers than the control group. The Ble-3IRL group had a greater number of immature fibers than the Ble group. At 30days, there was an absence of inflammation and equal proportion of mature and immature collagen fibers. All bleached groups showed a reduction in the volume of the pulp chamber. Three consecutive applications of RL and one IRL application can minimize damage to the pulp of bleached teeth, whereas three IRL applications can minimize pulp fibrosis. However, LLLT did not prevent deposition of tertiary dentin. This study describes LLLT protocols capable of minimizing inflammation and maturation of collagen fibers in pulp tissue after dental bleaching. However, the protocols proved insufficient for reducing the formation of tertiary dentin in bleached teeth.

Complete Genome Sequence of Streptococcus ratti JH145.

We report here the complete genome sequence of Streptococcus ratti strain JH145. Streptococcus ratti is a cariogenic species of mutans streptococcus that has been isolated from rat and human teeth. The strain JH145, derived from strain BHT-2, is interesting for oral health because it does not produce cariogenic lactic acid but shows robust biofilm production.