Tooth Replantation Research Articles

Role of osteopontin in the process of pulpal healing following tooth replantation in mice.

IntroductionThe role of osteopontin (OPN) following severe injury remains to be elucidated, especially its relationship with type I collagen (encoded by the Col1a1 gene) secretion by newly-differentiated odontoblast-like cells (OBLCs). In this study, we examined the role of OPN in the process of reparative dentin formation with a focus on reinnervation and revascularization after tooth replantation in Opn knockout (KO) and wild-type (WT) mice.MethodsMaxillary first molars of 2- and 3-week-old-Opn KO and WT mice (Opn KO 2W, Opn KO 3W, WT 2W, and WT 3W groups) were replanted, followed by fixation 3–56 days after operation. Following micro-computed tomography analysis, the decalcified samples were processed for immunohistochemistry for Ki67, Nestin, PGP 9.5, and CD31 and in situ hybridization for Col1a1.ResultsAn intense inflammatory reaction occurred to disrupt pulpal healing in the replanted teeth of the Opn KO 3W group, whereas dental pulp achieved healing in the Opn KO 2W and WT groups. The tertiary dentin in the Opn KO 3W group was significantly decreased in area compared with the Opn KO 2W and WT groups, with a significantly low percentage of Nestin-positive, newly-differentiated OBLCs during postoperative days 7–14. In the Opn KO 3W group, the blood vessels were significantly decreased in area and pulp healing was disturbed with a failure of pulpal revascularization and reinnervation.ConclusionsOPN is necessary for proper reinnervation and revascularization to deposit reparative dentin following severe injury within the dental pulp of erupted teeth with advanced root development.

Two-year Follow-up of Avulsed Teeth Submittted to Laser Therapies: A Case Report

Background: Replanted teeth can lead to critical biological conditions involving ankylosis and external root resorption. To prevent these occurrences, antimicrobial Photodynamic Therapy (aPDT) and Photobiomodulation Therapy (PBMT) can be used during the postoperative phase. Case Report: The present report described the clinical case of a patient, an adult male with the avulsion of teeth #11 and #21. Teeth were stored under dry conditions and replanted 18h after trauma. The pulp was removed before replantation and aPDT was performed using a low power laser (660 nm,100 mW, 9 J) in direct irradiation of the root canal. A passive flexible splint was fixed in place from tooth #13 to #23 for 4 weeks. The PBMT was applied three times a week, for the first 2 months, using the same laser device but with an infrared wavelength (808 nm, 100 mW, 3J). Clinical and radiographic examination supported the assessment of inflammatory/infectious resorption. Conclusion: The combination of laser therapy with endodontic procedures for treating traumatized teeth ensured successful clinical and radiographic outcomes at a 2-year follow-up examination.

Tooth transplantation and replantation: Biological insights towards therapeutic improvements

Transplantation and replantation of teeth are effective therapeutic approaches for tooth repositioning and avulsion, respectively. Transplantation involves transplanting an extracted tooth from the original site into another site, regenerating tissue including the periodontal ligament (PDL) and alveolar bone, around the transplanted tooth. Replantation places the avulsed tooth back to its original site, regenerating functional periodontal tissue. In clinical settings, transplantation and replantation result in favorable outcomes with regenerated PDL tissue in many cases. However, they often result in poor outcomes with two major complications: tooth ankylosis and root resorption. In tooth ankylosis, the root surface and alveolar bone are fused, reducing the PDL tissue between them. The root is subjected to remodeling processes and is partially replaced by bone. In severe cases, the resorbed root is completely replaced by bone tissue, which is called as "replacement resorption." Resorption is sometimes accompanied by infection-mediated inflammation. The molecular mechanisms of ankylosis and root resorption remain unclear, although some signaling mechanisms have been proposed. In this mini-review, we summarized the biological basis of repair mechanisms of tissues in transplantation and replantation and the pathogenesis of their healing failure. We also discussed possible therapeutic interventions to improve treatment success rates.

Antibiotics at replantation of avulsed permanent teeth? A systematic review.

At present there is no clear consensus whether systemic antibiotics should be administered at replantation of an avulsed permanent tooth. This systematic review and meta-analysis assessed the evidence on effectiveness and harms of the administration of systemic antibiotics at replantation of avulsed permanent teeth. In August 2020 a systematic literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, for systematic reviews, randomized controlled trials (RCT) and observational controlled studies in MEDLINE, PreMedline, Embase, and the Cochrane databases. The population of interest were medically fit patients with a replanted avulsed tooth. Main outcomes were tooth survival, periodontal healing, pulpal revascularization as well as (severe) adverse events. These outcomes were compared in patients who did and who did not receive systemic antibiotics. The GRADE methodology was used to assess the quality of evidence. The search yielded no RCTs, and none of the 7 included observational studies had the prime intent to investigate the effectiveness or harms of antibiotics. According to GRADE, the overall level of evidence was very low. The meta-analyses showed non-significant associations between the administration of systemic antibiotics on the one hand and tooth survival (1 study, RR = 3.70, 95% CI: 0.63-21.69), periodontal healing (meta-analysis of 6 studies RR: 1.07; 95% CI: 0.80-1.45), and pulpal revascularization (meta-analysis of 2 studies, RR: 0.36; 95% CI: 0.05-2.41) on the other hand. Currently there is no high-quality evidence to support the use of systemic antibiotics at replantation of avulsed permanent teeth. Hence, their routine use cannot be recommended in medically fit patients. Well-designed RCTs should be a priority on the research agenda.

The Prostacyclin Analog Iloprost Promotes Cementum Formation and Collagen Reattachment of Replanted Molars and Up-regulates Mineralization by Human Periodontal Ligament Cells

IntroductionThis study evaluated the use of the prostacyclin analog iloprost as a root surface treatment agent in promoting acellular cementum (AC) formation and collagen reattachment after tooth replantation in vivo. In addition, its effect on human periodontal ligament cell (hPDLC) mineralization was assessed in vitro. MethodsFirst molars of 8-week-old Wistar rats were extracted. In 1 group, the root surfaces were treated with Hank's balanced salt solution (HBSS), and the other group's root surfaces were treated with 10−6 mol/L iloprost before replantation. At day 30, maxillae were prepared for micro–computed tomographic imaging and histomorphometric analysis. The effect of iloprost on mineralization by hPDLCs was analyzed by mineralized nodule formation and quantitative polymerase chain reaction at 7 and 14 days. ResultsMicro–computed tomographic imaging demonstrated a significant higher bone volume in the iloprost groups, whereas the HBSS groups had extensive bone and root resorption. Histologic analysis revealed deposition of a thick AC layer along the root in the iloprost group with well-organized periodontal ligament fibers inserted into the cementum. The HBSS group demonstrated more osteoclasts than the iloprost group. In vitro, iloprost-treated hPDLCs had a significantly increased RUNX2, OSX, BSP, and ALP gene expression that coincided with an increased deposition of mineralized nodules. These effects were abrogated by a PGI2 receptor inhibitor. ConclusionsOur results revealed that iloprost promoted PDL regeneration in replanted molars. Furthermore, resorption of the roots was decreased, whereas AC deposition was stimulated. Iloprost-treatment increased hPDLC mineralization and was mediated by PGI2 receptor activation. These observations indicate that iloprost may be a promising root surface treatment agent.

The Effect of Using an Educational Poster on Mothers’ Knowledge of Emergency Management of Dental Avulsion

Introduction: Mothers are commonly the first ones who encounter the dental avulsion in children. High knowledge of them could greatly affect the success rate of treatment. The purpose of this study was to evaluate the effect of educational poster on the mother’s knowledge about management of dental avulsion.Materials and Methods: This study was conducted at the Department of Pediatric Dentistry, Guilan University of Medical Sciences from November 2020 to February 2021. After obtaining the informed consent, a questionnaire containing the mothers’ socio-demographic information and 8 questions regarding knowledge about dental avulsion was responded alone by 262 mothers (131 in the study group and 131 in control group) before educational poster presentation in the study group. After three months, the participants of both groups were re-evaluated using the same questionnaire. McNemar’s test and Generalized Estimating Equations (GEE) was used to analyze the data. Results with P < 0.05 were considered statistically significant. Results: Use of an educational poster improved the knowledge of participants of study group about dental avulsion, although this improvement was statistically significant in questions regarding immediate emergency action (P=0.003), appropriate time for replantation (P<0.001), cleaning before replantation of a dirty tooth(P=0.022) and suitable storage medium for transferring an avulsed tooth (P<0.001). It was found that variables like age, level of education, employment status and previous training had no significant effect on participants knowledge(P>0.05).Conclusion: Results showed that the use of posters as an educational method can effectively improve mothers’ knowledge about management of children’s dental avulsion.

Physiological and histological studies of dental response of Luxate tooth with application of VEGF

Background During luxate injury many dental tissue will be involved including pulp, periodontal ligament ,mucosa, hard dental tissue and alveolar bone with affecting the nerve and dental blood supplement. Growth factors may involved in healing process after replantation of tooth in its socket and the Vascular endothelial factor (VEGF ) is a potent one that increase angiogenesis and accelerate repairing and healing of dental pulp and the supporting tissues. The study was designed to illustrate the effect of application of growth factor on healing process of luxate molar tooth of rat. Materials & Methods Twenty male Wistar rats with luxate lower right first molar teeth were included in this study. The control were injected with normal saline (0.5μl ) around the apex of mesial root .Experimental group injected with VEGF (0.5μl ). Histological assessment of physiological responses of (dental pulp, cementum, periodontal ligament (PDL) and alveolar bone in both control and experimental groups with Receptor activator of nuclear factor kappa-Β ligand (RANKL) expression evaluation were recorded during the healing period in the examined tissue.

The Impact of Autologous Platelet Concentrates on the Periapical Tissues and Root Development of Replanted Teeth: A Systematic Review.

Introduction: In many cases, the replanted teeth may undergo resorption or ankyloses. Recent studies show that autologous platelet concentrates (APCs) may improve the outcomes of tooth replantation. The aim of this systematic review was to summarize and critically appraise the currently available literature on the use of APCs before tooth replantation. Methodology: An electronic search was conducted on the following research databases: PubMed/MEDLINE, ISI Web of Science, EMBASE and Scopus. The following medical subject heading (MeSH) keywords used were: ((tooth replantation) OR (replanted tooth) OR (teeth replantation) OR (replanted teeth)) AND ((autologous platelet concentrate) OR (platelet-rich plasma) OR (platelet-rich fibrin) OR (autologous platelet)). The studies’ data was extracted, and the research’ quality was rated using the CARE and ARRIVE protocols. Results: Ten case reports and three animal studies, one cell study and one study, which included both animal and in vitro experiments, were included in this review. In majority of the studies, APCs improved the outcomes of tooth replantation. However, there were various sources of bias in the most of the research, which may have influenced the results. Conclusions: Although majority of the studies indicate that APCs may improve outcomes of tooth replantation, majority of the studies contained numerous sources of bias. Additionally, the sample size of the included subjects is inadequate to predict the clinical efficacy of APCs in management of replanted teeth. Large-scale, multi-center and long-term studies are required to ascertain the efficacy of APCs in improve the outcomes of tooth replantation.

Delayed Replantation of Avulsed Permanent Maxillary Central Incisor with 2 Years of Follow Up: A Case Report

Abstract: Traumatic dental injuries are highly prevalent now a days. Present article discusses a case report of 13 years old male patient who reported with an dental emergency of left maxillary tooth avulsion. Patient kept the avulsed tooth in non physiologic media. Patient was treated as per the guidelines of interntional Association of Dental Traumatology. Replantation of avulsioned tooth is a preferred mode of treatment followed by physiologic splinting for a short period of time. Root canal therapy is required for the affected tooth in cases of delayed replantation. Patient’s clinical and radiographic follow up was done up to 2 years which showed patient remained asymptomic.

Platelet-derived growth factor-BB regenerates functional periodontal ligament in the tooth replantation

Tooth ankylosis is a pathological condition of periodontal ligament (PDL) restoration after tooth replantation. Platelet-derived growth factor-BB (PDGF-BB) has been proposed as a promising factor for preventing tooth ankylosis. Using rat tooth replantation model, we investigated whether PDGF-BB accelerates the repair of PDL after tooth replantation without ankylosis, and its molecular mechanisms. In PDGF-BB pretreated replanted teeth (PDGF-BB group), ankylosis was markedly reduced and functionally organized PDL collagen fibers were restored; the mechanical strength of the healing PDL was restored to an average of 76% of that in non-replanted normal teeth at 21 days. The numbers of PDGF-Rβ- and BrdU-positive cells in the periodontal tissues of the PDGF-BB group were greater than those of atelocollagen pretreated replanted teeth (AC group). Moreover, in the PDGF-BB group, the periodontal tissues had fewer osteocalcin-positive cells and decreased number of nuclear β-catenin-positive cells compared to those in the AC group. In vitro analyses showed that PDGF-BB increased the proliferation and migration of human periodontal fibroblasts. PDGF-BB downregulated mRNA expressions of RUNX2 and ALP, and inhibited upregulatory effects of Wnt3a on β-catenin, AXIN2, RUNX2, COL1A1, and ALP mRNA expressions. These findings indicate that in tooth replantation, topical PDGF-BB treatment enhances cell proliferation and migration, and inhibits canonical Wnt signaling activation in bone-tooth ankylosis, leading to occlusal loading of the PDL tissues and subsequent functional restoration of the healing PDL. This suggests a possible clinical application of PDGF-BB to reduce ankylosis after tooth replantation and promote proper regeneration of PDL.

Influence of clinical factors, IL4 and IL6 genes polymorphisms in functional healing in late replantation.

To investigate the genetic association in a sample of replanted teeth, it is necessary to observe the extreme phenotypes, such as, teeth that underwent functional healing and those extracted due to severe external root resorption. Thus, this study aimed to investigate the association of age of the patients, root development, storage media, and polymorphisms in the interleukin 4 (IL4) and interleukin 6 (IL6) genes with teeth that presented extreme outcomes, as functional healing or extraction, in a group whose replantation techniques did not follow the International Association of Dental Traumatology (IADT) 2012 guidelines. Forty-three avulsed and replanted teeth that did not follow IADT 2012 guidelines and underwent functional healing or were extracted were included. Periapical radiographs employed for this study were taken soon after tooth replantation and after 1 year. For genotypic IL4 and IL6 genes analysis, DNA of oral mucosa cells was extracted. Real-time- PCR performed for genotyping polymorphisms in IL4 and IL6 genes. Clinical and genetic variables were analyzed by the Chi-square test and the "Z" test. P values < .05 were considered significant. The results showed that functional healing and extraction were associated with storage media and with the rs2243268 of IL- 4 gene polymorphisms. As conclusion, the C rs2243268 allele of IL4 gene may have a positive relationship with functional healing teeth that were replanted not following the 2012 IADT guidelines. Keeping the tooth dry is associated to a fast loss of avulsed and replanted teeth after 1-year follow-up.

Role of chondroitin sulfate in the developmental and healing process of the dental pulp in mice.

Chondroitin sulfate proteoglycan (CSPG), one of the major extracellular matrices, plays an important part in organogenesis. Its core protein and chondroitin sulfate (CS) chain have a specific biological function. To elucidate the role of CS in the developmental and healing process of the dental pulp, we performed an experimental tooth replantation in CS N-acethylgalactosaminyltransferase-1 (T1) gene knockout (KO) mice. We also performed cell proliferation assay and qRT-PCR analysis for the WT and T1KO primary dental pulp cells using T1-siRNA technique and external CS. During tooth development, CS was diffusely expressed in the dental papilla, and with dental pulp maturation, CS disappeared from the differentiated areas, including the odontoblasts. In fully developed molars, CS was restricted to the root apex region colocalizing with Gli1-positive cells. In the healing process after tooth replantation, CD31-positive cells accumulated in the CS-positive stroma in WT molars. In T1KO molars, the appearance of Ki67- and Gli1-positive cells in the dental pulp was significantly fewer than in WT molars in the early healing stage, and collagen I-positive reparative dentin formation was not obvious in T1KO mice. In primary culture experiments, siRNA knockdown of T1 gene significantly suppressed cell proliferation in WT dental pulp cells, and the mRNA expression of cyclin D1 and CD31 was significantly upregulated by external CS in T1KO dental pulp cells. These results suggest that CS is involved in the cell proliferation and functional differentiation of dental pulp constituent cells, including vascular cells, in the healing process of dental pulp tissue after tooth injury.

Differential gene expression profiles of periodontal soft tissue from rat teeth after immediate and delayed replantation: a pilot study.

PurposeIn dental avulsion, delayed replantation usually has an uncertain prognosis. After tooth replantation, complex inflammatory responses promote a return to periodontal tissue homeostasis. Various types of cytokines are produced in the inflammatory microenvironment, and these cytokines determine the periodontal tissue response. This study aimed to identify the gene expression profiles of replanted teeth and evaluate the functional differences between immediate and delayed replantation.MethodsMaxillary molars from Sprague-Dawley rats were extracted, exposed to a dry environment, and then replanted. The animals were divided into 2 groups according to the extra-oral time: immediate replantation (dry for 5 minutes) and delayed replantation (dry for 60 minutes). Either 3 or 7 days after replantation, the animals were sacrificed. Periodontal soft tissues were harvested for mRNA sequencing. Hallmark gene set enrichment analysis was performed to predict the function of gene-gene interactions. The normalized enrichment score (NES) was calculated to determine functional differences.ResultsThe hallmark gene sets enriched in delayed replantation at 3 days were oxidative phosphorylation (NES=2.82, Q<0.001) and tumor necrosis factor-alpha (TNF-α) signaling via the nuclear factor kappa light chain enhancer of activated B cells (NF-κB) pathway (NES=1.52, Q=0.034). At 7 days after delayed replantation, TNF-α signaling via the NF-κB pathway (NES=–1.82, Q=0.002), angiogenesis (NES=–1.66, Q=0.01), and the transforming growth factor-beta signaling pathway (NES=–1.46, Q=0.051) were negatively highlighted.ConclusionsDifferentially expressed gene profiles were significantly different between immediate and delayed replantation. TNF-α signaling via the NF-κB pathway was marked during the healing process. However, the enrichment score of this pathway changed in a time-dependent manner between immediate and delayed replantation.

Management of External Root Resorption Associated with a Replanted Maxillary Central Incisor in an 11-Year-Old Patient: A Rare Case Report

Avulsion of permanent teeth is one of the serious injuries that require immediate attention in a dental setup and immediate replantation and splinting is the treatment of choice. The replantation of avulsed tooth improves aesthetics, occlusion, and function. Most common complication of tooth replantation is inflammatory external root resorption. Mineral trioxide aggregate is a calcium silicate-based material that maintains high alkaline pH for a longer duration and it helps in preventing inflammatory external root resorption. The purpose of this article is to report the successful management of inflammatory external root resorption associated with a replanted maxillary right central incisor using MTA in an 11-year-old girl with one-year follow-up.

Dental Trauma Management; Knowledge and Attitude of School Teachers in Rural Areas of Punjab

Objective: The purpose of study was to explore the level of knowledge and attitude in handling dental trauma among primary school teachers working in rural areas of Punjab, Pakistan. Method: This descriptive crossectional study was conducted in 47 primary government schools of different rural areas of district Narowal, Punjab, Pakistan. Collected sample size was 215 primary school teachers with minimum qualification of Bachelors in Arts. Data was collected using convenient sampling technique. SPSS version 25.0 was used for analysis and further results formation. Frequencies and Percentages were calculated for gender and qualification whereas mean and standard deviation was calculated for age. Results: Majority of participants reported that their knowledge about dealing with dental emergencies is not adequate 175(81.40%). Majority of participants were interested in having workshops on dealing with dental emergencies in school 160(74.42%). Conclusion: The knowledge and attitude of teachers towards management of dental trauma is lacking and a dire need of awareness programs and teacher training workshops has been felt after conducting this study as management of dental trauma is an important part of student safety management. Keywords: Dental Trauma, Teachers, Tooth Replantation, Tooth Avulsion

Effect of Photobiomodulation on Periodontal Ligament Cells Under Inflamed and Nutrient-Deficient Conditions Simulating Damaged Cells of Avulsed Teeth: An In Vitro Study.

Background: The prognosis of replanted teeth is depended on the vitality of periodontal ligament cells residual on the root surface. Photobiomodulation has photobiological effects that can promote cell vitality. The study aimed to explore the effect of photobiomodulation on the periodontal ligament cells under inflamed or starved conditions mimicking clinically damaged periodontal ligament cells of avulsed teeth and provide the adjuvant procedure for tooth replantation. Materials and methods: Normal, starved, or inflamed periodontal ligament cells were irradiated with an 808 nm laser at densities of 0, 1, 3, 5, or 10 J/cm2. The cell counting kit-8 (CCK-8) assay and scratch test were applied to determine the effects on the proliferation and migration of cells. Anti-inflammatory effects were assessed according to the mRNA expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) measured by reverse-transcription polymerase chain reaction. Osteogenic capacity was evaluated by alkaline phosphatase (ALP) staining, ALP activity assay, Alizarin Red S staining, and ALP and osteocalcin (OCN) mRNA expression. Results: The CCK-8 assay and scratch test demonstrated that the 808 nm laser significantly promoted proliferation and migration of normal condition periodontal ligament cells at a density of 3 J/cm2 versus 5 J/cm2 under the starved and inflamed conditions. Moreover, the 808 nm laser had anti-inflammatory effects and promoted osteogenesis of periodontal ligament cells at 3 J/cm2 under normal conditions, while photobiomodulation at 5 J/cm2 upregulated the osteogenesis of periodontal ligament cells under starved and inflamed conditions. Conclusions: The photobiomodulation of 808 nm laser reduced inflammation and improved the proliferation, migration, and osteogenesis of normal, starved, and inflamed periodontal ligament cells. These effects required a higher energy density under starved or inflamed conditions compared with normal conditions. The photobiomodulation of 808 nm has a potential application in root surface treatment for replanted teeth.

Nuclear factor-kappa B decoy oligodeoxynucleotide-loaded poly lactic-co-glycolic acid nanospheres promote periodontal tissue healing after tooth replantation in rats.

Excessive inflammation in the periodontal tissue after tooth replantation can lead to inflammatory root resorption and interrupt periodontal tissue regeneration. We tested the hypothesis that nuclear factor-κB decoy oligodeoxynucleotide-loaded poly lactic-co-glycolic acid nanospheres (NF-PLGA) inhibit excessive inflammation and promote healing of periodontal tissue after replantation in rats. The upper right incisors of rats were extracted, immersed in different specific solutions, and replanted. The rats were euthanized at 7, 14, and 28 days after replantation. Morphological evaluation with micro-CT and histological assessment with hematoxylin and eosin and tartrate-resistant acid phosphatase (TRAP) staining was performed. Additionally, we examined the expression of interleukin (IL)-1β, IL-6, transforming growth factor-β1 (TGF-β1), and fibroblast growth factor-2 (FGF-2) in the periodontal ligament (PDL) by performing immunohistological assessment. The NF-PLGA group showed significantly greater dental root thickness than the other experimental groups. Root resorption was not observed after the application of NF-PLGA on day 7. The application of NF-PLGA also resulted in a significantly lower number of TRAP-positive osteoclasts on days 7 and 14 after replantation. Significantly lower expression of IL-1β and IL-6 and higher expression of TGF-β1 and FGF-2 were observed under the application of NF-PLGA in the PDL. NF-PLGA promoted the healing process by inhibiting the initial excessive inflammatory response in the PDL, preventing root resorption, and promoting periodontal tissue regeneration. The findings also suggested that the PLGA nanospheres-mediated transfection of the decoy oligodeoxynucleotides can be useful for the clinical application of replanted tooth root surfaces.

The Effect of Mechanical Vibration on Osteogenesis of Periodontal Ligament Stem Cells

IntroductionAppropriate occlusal forces can prevent ankylosis after tooth replantation or transplantation. However, the “proper occlusal forces” on periodontal ligament (PDL) healing have not yet been defined due to insufficient in vitro studies and uncertain in vitro models. Herein, we presented a mechanical vibration device as an in vitro model to determine such favorable occlusal forces. MethodsHuman periodontal ligament stem cells (hPDLSCs) were exposed to mechanical vibration force with 4 frequencies (30, 90, 150, and 210 rpm). Cell viability and the expression of osteogenic differentiation-related genes and proteins were tested in vitro. The calvarial transplantation experiment was performed to assess the bone formation ability of 150 rpm mechanical vibration stimulation (MVS). ResultsMVS at 150 and 210 rpm significantly reduced cell viability in the early stages. The 150-rpm MVS decreased osteogenic marker expression at the early time point (3 days) but had no harmful effects at the late time point (14 days). Furthermore, hPDLSC cell sheets treated with 150-rpm MVS had potential to decrease bone formation in rat calvarial defects serendipitously and facilitated functional PDL-like tissue formation. ConclusionsWe found that MVS at a frequency of 150 rpm could provide a strategy for a transient reduction in the osteogenic potential of hPDLSCs and promote PDL-like tissue formation. Thus, 150-rpm MVS could be used as a controllable proper occlusal force to prevent ankylosis and promote PDL healing after tooth replantation or transplantation.

A Novel Surgical Approach for the Successful Removal of Overextruded Separated Endodontic Instruments

Endodontic procedures can result in various complications. Separation of the endodontic instrument is a common complication of incorrect use or overuse of the instrument. However, a separated endodontic instrument may hinder cleaning and shaping during endodontic treatment procedures, which can potentially impact prognosis. Therefore, it is necessary to manage this complication by removal of the separated instruments from inside the root canal. Although several devices are used, nonsurgical removal for retreatment remains difficult. We report the case of a failed attempt to manage a separated endodontic instrument nonsurgically by a private dentist, which resulted in extrusion of the instrument beyond the root apex and its migration into the mandible. We describe a novel surgical approach involving intentional tooth replantation combined with alveolar osteotomy. There have been few reports on the management of separated endodontic instruments that were pushed out beyond the root apex. Our novel surgical approach suggests a technique for the potential removal of a separated endodontic instrument extruded beyond the root apex.

Considerações sobre reimplantes dentários: condutas clínicas e ortodônticas frente a estas situações

Based on a literature review, the objective of this study is to establish the degree of dental analysis or root resorption that allows replanted teeth to be moved using orthodontic appliance. Some aspects of avulsion and replanted teeth such as etiology, clinical approach and prognosis are considered. It is also presented a literature review of orthodontic tooth movement. According to most authors, the replant is frequently followed by analysis that doesn't allow orthodontic movement. Nevertheless, the lack of resorption signs during a minimum period of one year allows orthodontic treatment when necessary.