Enamel matrix derivative for replanted teeth in animal models: a systematic review and meta-analysis

Enamel matrix derivative in the treatment of tooth replantation: from a biological basis to clinical application

BACKGROUND

An efficient therapeutic strategy for patients with replanted teeth has been extremely challenging because complete displacement of the teeth is inevitably accompanied by severe damage to periodontal tissue. Enamel matrix derivative (EMD) shows promise for periodontal regeneration, but its effects on replanted teeth remain unknown. This study systematically summarized the biological basis of EMD in replantation dental therapy and assessed its effect on clinical prognosis.

METHODS

Potential studies were searched via the Cochrane Library, Web of Science and PubMed databases from inception to November 23, 2023.

RESULTS

A total of 329 patients with 375 replanted teeth met the inclusion criteria. Our pooling results indicated that EMD did not provide a numerical advantage for restoring normal PDL healing in replanted teeth (RR=0.38, P=0.161). A significantly lower extraction risk was observed in EMD-treated group than non-EMD-treated group (RR=0.47, P=0.001). Moreover, the survival rate of replanted teeth with root resorption was significantly increased by the application of EMD (RR=2.21, P=0.017). Although the pooled outcomes suggested increased incidence of surface resorption (RR=1.19, P=0.730) and decreased risk of inflammation resorption (RR=0.68, P=0.560) among replanted teeth with resorption in the EMD-treated group, neither difference was statistically significant.

CONCLUSION

For patients with replanted teeth, EMD treatment may not result in a numerical increase in normal PDL healing. However, as a biological regulator, EMD may arrest the progression of resorption, thus reducing the risk of extraction in the early stage. Well-designed randomized trials are required to validate these results due to the poor quality of evidence.

Fibrillin protein, a candidate for creating a suitable scaffold in PDL regeneration while avoiding ankylosis

The tooth is stabilized by fiber-rich tissue called the periodontal ligament (PDL). The narrow space of the PDL does not calcify in the physiological state even thought it exists between two calcified tissues, namely, the cementum of the root and alveolar bone. Two situations that require PDL regeneration are periodontitis and dental trauma. Periodontitis induces the loss of PDL and alveolar bone due to inflammation related to infection. Conversely, in PDLs damaged by dental trauma, accelerating bone formation as an overreaction of the healing process is induced, thereby inducing dentoalveolar ankylosis at the tooth root surface. PDL regeneration following dental trauma must therefore be considered separately from periodontitis. Therefore, PDL regeneration in dental trauma must be considered separately from periodontitis. This review focuses on the components involved in avoiding dentoalveolar ankylosis, including oxytalan fibers, aggregated microfibrils, epithelial cell rests of Malassez (ERM), and TGF-β signaling. During root development, oxytalan fibers produced by PDL cells work in collaboration with the epithelial components in the PDL (e.g., Hertwig's root sheath [HERS] and ERM). We herein describe the functions of oxytalan fibers, ERM, and TGF-β signals which are involved in the avoidance of bone formation.

Permanent tooth avulsion in children and adults: Therapeutic options for longer survival

Introduction: Permanent tooth avulsions (traumatic extraction; total luxation) are one ofthe most severe permanent tooth injuries and can occur as single injuries or associated with other dental injuries or injuries to the face and jaws region. They are defined as the luxation of teeth from the alveoli with complete rupture of periodontal fibres, or with one part attached to the rootcementum and the other to the alveolar bone, thus compromising the dental pulp, root cementum,and alveolar bone. The high prevalence and numerous negative consequences on the stomatognathic systems they have suggest permanent tooth avulsions should be regarded as an important public health problem. The aim: is to point out the therapeutic possibilities of permanent tooth avulsion that can ensure their longer survival in the oral cavity. Conclusion: The treatment strategy for avulsed permanent teeth is always based on limiting root canal infection and periradicular inflammation, shifting the balance from unfavourable (replacement resorption) to favourable (periodontal) healing. The success of therapy and periodontal healing depend on the duration and conditions of extraoral tooth preservation, the degree of damage to the periodontal ligament, and the condition of the pulp.

Evidence mapping and quality assessment of systematic reviews in dental traumatology

BACKGROUND/AIMS

Evidence mapping of systematic reviews (SRs) systematically and comprehensively identifies, organizes, and summarizes the distribution of scientific evidence in a field. The aims of this study were to delineate domains in dental traumatology (DT), evaluate the existing SRs within the domains, and identify the paucity of evidence for future research.

METHODS

Domains and sub-domains of DT were established according to the methods of qualitative research. The protocol for evidence mapping was prepared as per the guidelines of GEM and PRISMA. The search strategy was formulated using words and MeSH terms in eight databases without restriction of languages and year of publication. Gray literature, protocol registries, and references of selected articles were also searched. Duplicates were removed, and the final selection of SRs was completed. Data extraction and quality analysis using the ROBIS tool and the PRISMA checklist were performed.

RESULTS

The overall search resulted in 64 SRs from 1999 to 2020 with 44 published in last six years. The highest number of SRs had been performed in the Prognostic domain (n = 19) followed by the domains of Epidemiology (n = 15), Therapeutics (n = 10), Oral Biology (n = 7), Diagnostics (n = 6), Preventive (n = 5), and Research Methods (n = 2). Within each domain, there were variabilities in the number of reviewers, a priori protocols, search limitations, risk of bias methods, and meta-analysis. Of the SRs, including 4 Cochrane reviews, 28.4% were inconclusive. A low risk of bias was found in 48.4% of the SRs. Among the registered and ongoing SRs, six were from the domain of epidemiology, two in the domain of therapeutics, five from prognostics, and one each in the domains of prevention and research methods.

CONCLUSION

The SRs in DT could be mapped in seven domains with variabilities in the methods. The majority had an a priori registered protocol and a low risk of reporting errors. Within the Epidemiology and Preventive domains, SRs were present in all the sub-domains with the majority demonstrating low-risk of bias (ROB). The domain of prognosis had SRs in most sub-domains but with a high ROB. Insufficient numbers of SRs were present in most sub-domains of the Diagnostics, Therapeutics, Research Methods and Oral Biology domains.

Periodontal wound healing following reciprocal autologous root transplantation in class III furcation defects

Purpose

Furcation involvement in the molars is difficult to treat, and has been recognized as a risk factor for tooth loss. Although periodontal regenerative therapies, including guided tissue regeneration and various types of bone grafts, have been applied to furcation defects, the effects of these treatments are limited, especially in large class III furcation defects. The purpose of this pilot study was to investigate the effect of reciprocal autologous root transplantation on periodontal wound healing and regeneration in class III furcation defects in dogs.

Methods

Furcation defects (7 mm wide and 6 mm high) were surgically created after root separation of the unilateral third and fourth premolars in 4 dogs. Eight furcation defects were randomized to receive either reciprocal autologous root transplantation (test) or no further treatment (control). In the test group, the mesial and distal roots were transplanted into the distal and mesial extraction sockets, respectively. The animals were sacrificed 10 weeks after surgery for histologic evaluation.

Results

The healing pattern in the control group was characterized by extensive collapse of the flap and limited periodontal regeneration. New bone formation in the test group (3.56±0.57 mm) was significantly greater than in the control group (0.62±0.21 mm). Dense collagen fibers inserting into the residual cementum on the transplanted root surfaces were observed in the test group. Slight ankylosis was observed in 2 of the 4 specimens in the test group on the mesiodistal sides where the root-planed surfaces faced the existing bone. Root resorption (RR) was detected in both the control and test groups.

Conclusions

Within the limits of this study, it can be concluded that reciprocal autologous root transplantation was effective for bone regeneration in class III furcation defects in dogs. However, further studies are required to standardize the approach in order to prevent unwanted RR prior to clinical application.

The Effect of Root Coating with Titanium on Prevention of Root Resorption in Avulsed Teeth: An Animal Study

Introduction:

Tooth avulsion is a real dental emergency. If immediate replantation is not performed, the avulsed tooth may be lost due to inflammatory or replacement resorption. This animal study aimed to evaluate the bone response to the titanium coating of the root surface as an artificial barrier, and prevention of resorption of avulsed teeth.

Methods and Materials:

This experimental study was conducted on four male dogs. The dogs were randomly divided into two groups for assessment at two and eight weeks. Four teeth were extracted in each animal. The root surfaces of the test group were coated with a titanium layer using the Electron Beam Deposition system. After 24 h, replantation of the teeth was performed. Two animals were sacrificed after two weeks and the remaining dogs were killed after eight weeks. The presence of inflammation, inflammatory resorption, replacement resorption, periodontal regeneration, periapical granuloma and ankylosis were evaluated through histological analyses.

Results:

Inflammatory root resorption was not present in any tooth except one tooth in the coated group after eight weeks. Replacement resorption was noted just in three of the non-coated teeth after two weeks and two teeth after eight weeks. The McNemar's test revealed that the frequency of replacement resorption in the non-coated group was significantly higher than the coated group (P=0.031).

Conclusion:

Based on the results of this study, it seems that coating the root surfaces of avulsed teeth with titanium may control the replacement root resorption.

Influence of enamel matrix derivative on healing of root surfaces after bonding treatment and intentional replantation of vertically fractured roots

BACKGROUND/AIM

The objectives of this study were to histopathologically evaluate cementum regeneration on root surfaces when an enamel matrix derivative (EMD) was used to bond a vertically fractured root and to evaluate the effectiveness of EMD in inhibiting root resorption.

MATERIAL AND METHODS

A total of 40 roots from 24 maxillary premolars in beagles were used. The root was vertically fractured using a chisel and mallet. Super-Bond was then used to bond the fractured root. In the experimental group, the root surface was treated with ethylenediaminetetraacetic acid and an EMD. The control group received no treatment. The root was then replanted in its original location. Histopathological observation and measurement using image-analyzing software were carried out after 8 weeks.

RESULTS

In the experimental group, shallow resorption cavities developed on the root planed surfaces with new acellular cementum appearing over them. In the control group, no new cementum was seen on the planed surfaces, and there was connective tissue joining the roots. In some of the samples, resorption and multinucleated giant cells were seen. The experimental group showed a significantly larger volume of cementum formation (P < 0.001), and the volume of root resorption was significantly smaller (P = 0.004).

CONCLUSION

When bonding and replanting tooth roots after a vertical fracture, the application of EMD was effective in regenerating cementum on root surfaces from which periodontal ligament had been lost in the area around the fracture line and in reducing the incidence of root resorption.

The effect of cathepsin K inhibitor on osteoclastic activity compared to alendronate and enamel matrix protein

BACKGROUND/AIM

There have been several attempts to treat delayed replantation with agents that inhibit root resorption. The purpose of this study was to assess the effectiveness of cathepsin K inhibitor in inhibiting osteoclastic activity compared to that of alendronate and enamel matrix protein.

MATERIALS AND METHODS

Murine RAW 264.7 cells were cultured in the presence of the receptor activator of NF-kB and lipopolysaccharide, followed by treatment with odanacatib, alendronate, or Emdogain at various concentrations. After drug treatment, an MTT assay was performed to evaluate cytotoxicity, while reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assays were performed to determine the expression levels of interleukin-1β, interleukin-6, prostaglandin E2, and tumor necrosis factor-α. Data were analyzed by one-way anova and Tukey's post-hoc test (P < 0.05).

RESULTS

Of all tested agents, Emdogain resulted in the least cytotoxicity on RAW 264.7 cells, while 10(-9) M odanacatib had the largest suppressive effects on the expression levels of inflammatory cytokines.

CONCLUSIONS

Odanacatib inhibits osteoclastic activity, showing the possibility as a treatment agent for delayed replantation of avulsed teeth.

What is the Best Root Surface Treatment for Avulsed Teeth?

Dental avulsion is the most severe type of traumatic tooth injuries since it causes damage to several structures and results in avulsion of the tooth from its socket. Management protocols for avulsed teeth should include management of the pulp and periodontal ligament (PDL) cells in order to improve the long-term prognosis and survival of these teeth. The prognosis of the treatment as well as the survival of an avulsed tooth depends on intrinsic and extrinsic factors, such as the duration of the tooth's extra-alveolar period, replantation time, the type of storage medium, PDL status and duration of splinting. Recent research has led to the development of storage media. However, there is not yet a single solution that fulfills all requirements to be considered as the ideal medium for temporary storage of avulsed teeth, and research on this field should carry on. On the other hand in case of delayed replantation, due to the great risk of tooth loss after avulsion, different root surface treatments have been proposed to prevent and delay root resorption before replantation. For this purpose, researchers have applied some different root surface treatment modalities in delayed replantation of avulsed teeth. Several protocols have been used to maintain PDL viability; some involve fluorides, steroids, sodium alendronate, enamel matrix derivatives (EMD) and basic fibroblast growth factor (bFGF, FGF-2). Among these applications, bFGF shows promising results in the regeneration of natural tooth structures and tissues. Better understanding of mechanism of bFGF may help to improve new technologies of regeneration of tooth structures.

The effects of bone morphogenetic protein-2 and enamel matrix derivative on the bioactivity of mineral trioxide aggregate in MC3T3-E1cells

Objectives

The effects of bone morphogenetic protein-2 (BMP-2) and enamel matrix derivative (EMD) respectively with mineral trioxide aggregate (MTA) on hard tissue regeneration have been investigated in previous studies. This study aimed to compare the osteogenic effects of MTA/BMP-2 and MTA/EMD treatment in MC3T3-E1 cells.

Materials and Methods

MC3T3-E1 cells were treated with MTA (ProRoot, Dentsply), BMP-2 (R&D Systems), EMD (Emdogain, Straumann) separately and MTA/BMP-2 or MTA/EMD combination. Mineralization was evaluated by staining the calcium deposits with alkaline phosphatase (ALP, Sigma-Aldrich) and Alizarin red (Sigma-Aldrich). The effects on the osteoblast differentiation were evaluated by the expressions of osteogenic markers, including ALP, bone sialoprotein (BSP), osteocalcin (OCN), osteopontin (OPN) and osteonectin (OSN), as determined by reverse-transcription polymerase chain reaction analysis (RT-PCR, AccuPower PCR, Bioneer).

Results

Mineralization increased in the BMP-2 and MTA/BMP-2 groups and increased to a lesser extent in the MTA/EMD group but appeared to decrease in the MTA-only group based on Alizarin red staining. ALP expression largely decreased in the EMD and MTA/EMD groups based on ALP staining. In the MTA/BMP-2 group, mRNA expression of OPN on day 3 and BSP and OCN on day 7 significantly increased. In the MTA/EMD group, OSN and OCN gene expression significantly increased on day 7, whereas ALP expression decreased on days 3 and 7 (p < 0.05).

Conclusions

These results suggest the MTA/BMP-2 combination promoted more rapid differentiation in MC3T3-E1 cells than did MTA/EMD during the early mineralization period.