A long-term study of 370 autotransplanted premolars. Part IV. Root development subsequent to transplantation

Tooth autotransplantation with adjunctive application of enamel matrix derivatives using a digital workflow: A prospective case series

OBJECTIVES

Digital protocols and bioactive materials may reduce complications and improve tooth autotransplantation (ATT) success and survival rates. This prospective study assesses the performance of a fully digital autotransplantation protocol of close-apex molars with the adjunctive application of Enamel Matrix Derivatives (EMD).

METHODS

Twelve adult patients with 13 hopeless molar teeth were replaced with autotransplantation of closed apex third molars. Outcomes, including success and survival rates, clinical, endodontic, radiographic, patient-reported outcome measures (PROMs), and digital image assessments, were conducted over a two-year follow-up period.

RESULTS

Survival and success rates were 100% and 91.2%, respectively, with no progressive inflammatory or replacement root resorption (ankylosis) except for one tooth presenting radiographic furcation involvement. A significant probing depth reduction of 2.4 ± 2.58 mm and CAL gains of 2.8 ± 3.03 mm were observed in transplanted teeth compared to the hopeless receptor teeth. Radiographic bone levels remained stable throughout the study period (-0.37 ± 0.66 mm), and digital image assessments showed minimal alveolar ridge width changes (-0.32 to -0.7 mm) and gingival margin changes (-0.95 to -1.27 mm) from baseline to last visit. PROMs indicated very high patient satisfaction.

CONCLUSION

The use of a digital ATT protocol with adjunctive use of EMD in closed-apex third molars demonstrated promising short-term high success and survival rates. Additionally, this type of therapy adequately preserves the dimensions of the alveolar ridge in the receptor site.

CLINICAL SIGNIFICANCE

This is the first prospective clinical study examining the effect of a digital tooth autotransplantation protocol combined with the application of EMD. It demonstrates that this approach is an effective treatment for replacing hopeless teeth and also validates the digital assessment of ATT alveolar ridge preservation at the recipient site.

Interdisciplinary management of an adolescent patient with a severely impacted mandibular canine

Impacted mandibular canines often result in a variety of clinical dilemmas. Orthodontic disimpaction of severely displaced mandibular canines may be extremely challenging and associated with significant patient discomfort and a high risk of iatrogenic damage. This case report demonstrates the interdisciplinary management of a horizontally impacted permanent mandibular canine, utilising a combination of three-dimensional radiology, biomodel fabrication and subsequent endodontic treatment. © 2024 Australian Dental Association.

Midterm outcomes of autogenous mature third molars transplantation into surgically created sockets: A retrospective cohort study

BACKGROUND/AIMS

The purpose of this study was to observe the outcome of mature third molars transplantation into surgically created sockets with the assistance of computer designed three dimensional (3-D) printed replicas and compare its outcome with the conventional fresh socket autotransplantation.

MATERIAL AND METHODS

This study included total of 96 mature third molars autotransplanted in 96 cases with the guidance of computer designed 3-D printed replicas. Forty-eight teeth autotransplanted into surgically created sockets were enrolled into the surgically created socket group and 48 teeth conventionally autotransplanted into fresh sockets were enrolled into the fresh socket group. In the surgically created socket group, mature third molars were autotransplanted into surgically prepared sockets at the site of previously missed or extracted molars in the alveolar bone and in the fresh socket group, autotransplantation of mature third molars were performed in fresh sockets of extracted diseased molars simultaneously. After transplantation, the visual analogue scale (VAS) score, Landry Wound Healing Index (LWHI), mobility and probing depth (PD) of the transplanted teeth were measured and the patient satisfaction questionnaire were held in both group. All patients underwent clinical and radiographic examinations during the follow-up.

RESULTS

During the mean follow-up period of 47.63 ± 16.78 months (range 18-78 months), 92 out of 96 teeth remained in situ without clinical or radiographic complications with overall success rate of 95.83%. No statistically significant differences were found in success and survival rates between the two group. The average extra-oral time of the donor teeth were 60.76 ± 22.41 s and mean positioning trials of the donor teeth were 2.43 ± 1.19. The VAS score at Day 1 in the surgically created socket group was higher than the fresh socket group (p < .05). LWHI scores in the surgically created group were lower than the fresh socket group during the first 2 weeks (p < .05). The degree of mobility of the transplanted teeth in both group showed no statistically significant difference during the first 3 months. PD in the surgically created group were higher than the fresh socket group in the first month but there were no statistically significant difference after 1 month. Twenty-six out of 48 cases in the surgically created group needed crown restoration while only 10 cases went through crown restoration in the fresh socket group. Most patients in both group were satisfied with the treatment.

CONCLUSIONS

Autogenous mature third molars transplantation into surgically created sockets is as effective as conventional fresh socket transplantation. This technique is worth recommending in carefully selected cases and optimistic results can be achieved.

Use of 3D printing models for donor tooth extraction in autotransplantation cases

OBJECTIVE

To clarify whether the 3D printing model has auxiliary functions in toto extraction of donor tooth in autotransplantation cases.

METHODS

Two hundred and sixty patients who would have operation of ATT were divided into two groups. In group 1, determination of the tooth extraction in toto was predicted only according to the clinical and imaging examination. In group 2, the prediction was performed according to the clinical and imaging examination as well as the 3D model of donor tooth pre-extraction. A prespctive clinical study was designed on intra-group comparison between the predicted and actual donor teeth situation when extraction in cases of ATT. The consistent rate for the predicted results and the actual results were compared with the two groups.

RESULTS

A remarkable difference was observed between the predicted results and the actual results of tooth positions and root numbers in group without model (p < 0,05). The consistency rate of the model group (94.62%) was significantly higher than that of non 3D model group (86.15%) (p = 0.034).

CONCLUSION

The 3D printing model for the donor tooth is helpful for dentists to predict the accuracy of toto extraction of donor teeth in autotransplantation cases.

An evaluation of 910 premolars transplanted in the anterior region-A retrospective analysis of survival, success, and complications

AIM

The aim this retrospective analysis was to evaluate the survival, success and possible complications of transplanted premolars to the anterior region subdivided in development stage and patient's age.

MATERIALS AND METHODS

The material comprised patients that underwent a tooth transplantation between April 2004 and December 2021. A total of 910 premolars were transplanted in 707 patients. Tooth mobility, oral hygiene, and periodontal parameters were clinically evaluated. Standardized radiographs were used to evaluate pulpal and periodontal healing and root formation. The cumulative survival rate was calculated using the Kaplan-Meier method.

RESULTS

The data were subdivided in three groups based on the stage of root development and patient's age. The average age at surgery was 16 years. The main indication for transplantation was trauma, followed by agenesis and other indications. Two premolars were lost during the whole observation period. The overall survival and success in the immature premolars group after an observation period of 10 years was 99.8%. The 10-year survival and success rate when fully developed premolars were transplanted in the anterior region in adolescents were 100% and 96.3%, respectively. In adults, the 10-year survival and success rate were 87.5%.

CONCLUSION

Transplantation of premolars with developing and fully developed roots to the anterior region in children, adolescents, and adults is a predictable treatment modality.

Evaluation of the 3D Technology in the Auto-transplantation: An Original Research

Introduction

Using three-dimensional printed duplicates of the donor teeth, three-dimensional auto-transplantation is a medical procedure that moves a tooth from one location inside a patient to another. The intraoperative practicability during 3D auto-transplantation of teeth was evaluated in the present study.

Material and Methods

A prospective multicenter clinical study was done among the subjects. "Preoperative cone-beam computed tomography imaging," "computer-assisted design (CAD)," and "computer-assisted manufacturing (CAM)" were used in all operations to make a 3D duplicate of the donor teeth. The clinical parameters that were evaluated were the time required for the fit, number of attempts to fit, and intra-operative experience.

Results

Canines, premolars, molars, and one extra tooth were all transplanted during the 200 auto-transplantation surgeries among 152 subjects. An initial satisfactory fit of the donor tooth and an extra-alveolar time of less than one minute were achieved in 80% of the surgeries. The extra-alveolar time exceeded 3 minutes in ten teeth. Difficulties that were faced were related to the imaging, patient cooperation, and the bone quality.

Conclusions

The application of the duplicate teeth by 3D printing of a donor tooth all through auto-transplantation techniques reduced the time the tooth stays extra-alveolar as well as the efforts at transplant fitting during implantation. This allowed for more challenging surgeries as well as a speedy and reliable therapy.

Validation of a Cox prognostic model for tooth autotransplantation

OBJECTIVES

This study aimed to validate our Cox proportional hazards prognostic model for autotransplantation of teeth with complete root formation using prognostic index (PI) and determine whether the prognosis can be predicted.

PATIENTS AND METHODS

The Protocol group, as a training data set for validation, consisted of 259 autotransplanted teeth to create a PI using the Cox model, as described previously. The Pre-protocol group, as the first validation data set, consisted of 95 autotransplanted teeth treated without a protocol. The Post-protocol group, as the second validation data set, consisted of 61 autotransplanted teeth obtained after the establishment of the prognostic model. Because four prognostic factors, including history of root canal treatment (yes), number of roots (multirooted), source of donor tooth (maxillary tooth), and duration of edentulism (≥2.5 months), were selected as a Cox prognostic model, 16 patterns of PI were constructed. First, the autotransplantated teeth in the Protocol group were divided into low- and high-risk groups respectively according to the median of PI as the cutoff value. The survival curves of low- and high-risk groups were calculated using the Kaplan-Meier method and tested using the log-rank test. Then, in the Pre- and Post-protocol groups, all transplanted teeth were divided into low-and high-risk teeth by the median of PI and the survival curves of low- and high- risk teeth were analyzed statistically in a similar manner.

RESULTS

The survival curves of the low- and high-risk groups diverged significantly in the Protocol and Post-protocol groups. In the Pre-protocol group, the curves of the low- and high-risk groups were separated, and the low-risk survival rate was improved.

CONCLUSIONS

Our Cox prognostic model for autotransplantation of teeth with complete root formation was useful in predicting the prognosis by external validation using PI.

Anterior tooth autotransplantation: a case series

Tooth autotransplantation is the technique of transplanting embedded, impacted or erupted teeth from one site into another in the same individual. It is relatively common for the anterior segment of the mouth to be affected by traumatic tooth injuries, impacted and/or congenitally missing permanent teeth. Autotransplantation of teeth into the anterior dental arch can provide unrivalled biological solutions when such issues arise in this critical aesthetic zone, particularly for adolescent patients. The combination of meticulous pre-surgical assessment, synergistic interdisciplinary collaboration and carefully performed anterior tooth autotransplantation has been demonstrated to achieve impressive outcomes, with respect to both transplant survival and clinical success. © 2023 Australian Dental Association.

Multimodal Imaging of Dental Pulp Healing Patterns following Tooth Autotransplantation And Regenerative Endodontic Treatment

INTRODUCTION

Understanding the healing process of dental pulp after tooth autotransplantation (TAT) and regenerative endodontic treatment (RET) of immature teeth is important both clinically and scientifically. This study aimed to characterize the pattern of dental pulp healing in human teeth that underwent TAT and RET using state-of-the-art imaging techniques.

MATERIALS AND METHODS

This study examined four human teeth, two premolars that underwent TAT and two central incisors that received RET. The premolars were extracted after one year (case 1) and two years (case 2) due to ankylosis, while the central incisors were extracted after three years (cases 3 and 4) for orthodontic reasons. Nanofocus x-ray computed tomography was used to image the samples before being processed for histological and immunohistochemical analysis. Laser scanning confocal second harmonic generation imaging (SHG) was used to examine the patterns of collagen deposition. A maturity-matched premolar was included as a negative control for the histological and SHG analysis.

RESULTS

Analysis of the four cases revealed different patterns of dental pulp healing. Similarities were observed in the progressive obliteration of the root canal space. However, a striking loss of typical pulpal architecture was observed in the TAT cases, while a pulp-like tissue was observed in one of the RET cases. Odontoblast-like cells were observed in cases 1 and 3.

CONCLUSION

This study provided insights into the patterns of dental pulp healing after TAT and RET. The SHG imaging sheds light on the patterns of collagen deposition during reparative dentin formation.

Tooth autotransplantation gives teeth a second chance at life: A case series

Traditional transplantation, surgical extrusion and intentional replantation procedures are important treatment options that clinicians may consider performing in their daily clinical practice. There should be a well-constructed treatment plan for teeth with problems. In this paper, we present a series of case reports on three treatment methods used in autologous tooth transplantation and a literature review on the prevention of postoperative complications and the advantages of autologous tooth transplantation compared to dental implantation. The purpose of this study was to improve the understanding of autologous tooth transplantation.

Implications of Post-Traumatic Treatment of Immature Maxillary Incisors

The aim of this review was to discuss traumatic dental injuries in view of their treatment implications to provide an evidence-based resource for clinicians when planning treatment for traumatised immature maxillary incisors. Dental trauma to immature maxillary incisors can result in various complications, such as critical fractures, resorptions, or ankylosis, and might lead to tooth loss. Traumatised teeth may exhibit various unaesthetic discolourations as a result of different dental trauma sequelae or materials used for treatment. All of the above can influence patients' social experience, including self-esteem, confidence, eating and speaking abilities, as well as proper development and growth of the jaw bones. Treatment of traumatised immature incisors should focus not only on the acute phase but on the long-term consequences. Any time gained with the tooth in the jaw bone, free of infection, is an achievement, as it allows normal growth and development. All these aspects are discussed in this narrative review, and an evidence-based summary resource is suggested for clinicians to use when planning treatment for traumatised immature maxillary incisors.

Tooth auto-transplantation: A bibliometric analysis of the top 100 most-cited articles

BACKGROUND/AIM

Tooth auto-transplantation has recently gained high clinical acceptance. The aim of this study was to identify the top 100 most-cited articles regarding tooth auto-transplantation, to analyse multiple citations and publication metrics and to outline the historical scientific advancements in this field.

MATERIALS AND METHODS

An advanced search of the Clarivate Analytics' Web of Science 'Core Collection' and Elsevier's Scopus databases utilising specific keywords related to tooth auto-transplantation between 1971 and 2021 was performed. The retrieved articles were ranked in descending order based on their Web of Science citation counts and further cross-matched with citation data from Scopus. The extracted data included citation counts, citation density, level of evidence, year of publication, contributing authors names and institutes, corresponding author's address, journal of publication, journal local citations index, cumulative growth index, keywords and keywords Plus. Data analysis was performed using descriptive statistics and graphical mapping.

RESULTS

A total of 1290 articles were retrieved. The top 100 most-cited articles received a total of 4899 (Web of Science) and 5250 (Scopus) citations. Among these, cohort studies (29%) and case series (18%) were the most common study designs. Scandinavian countries produced major contributions in defining the top 100 most-cited articles and ranked within the top 5 countries based on the number of publications and citations per year. The greatest contributing authors were Schwartz O (n = 12), Andreasen JO (n = 8) and Paulsen HU (n = 6), and they were affiliated with Copenhagen, Denmark. The top contributing journals were American Journal of Orthodontics and Dentofacial Orthopedics, International Journal of Oral and Maxillofacial Surgery, Oral Surgery Oral Medicine Oral Pathology Oral Radiology, European Journal of Orthodontics, Dental Traumatology and Journal of Oral and Maxillofacial Surgery.

CONCLUSION

This bibliometric analysis revealed a large geographical scientific interest and broad development in the field of tooth auto-transplantation spanning multiple dental disciplines.

Extraoral Root-End Resection May Promote Pulpal Revascularization in Autotransplanted Mature Teeth-A Retrospective Study

Tooth germ autotransplantation of open apices of the teeth exhibits high pulpal healing rates, whereas that of mature permanent teeth normally causes irreversible pulpal necrosis. Extraoral root-end resection (EORER) during transplantation may promote pulpal revascularization (PRV) in transplanted mature teeth and reduce endodontic treatment requirement. This study compared the primary outcomes of survival rates, PRV, and root resorption and determined relevant confounders in autotransplanted mature and immature teeth. The medical charts of consecutive patients who underwent tooth autotransplantation between January 2017 and March 2021 were evaluated. Teeth with a documented follow-up of at least 1 year were included. During the study period, 59 teeth were transplanted in 44 patients. Overall, 2 teeth were excluded owing to missing data; 57 teeth were analyzed, including 25 mature teeth additionally treated with EORER. After a mean follow-up of 21.2 ± 16.1 months, no significant differences in primary outcomes were detected. Fifty-five teeth remained in situ (96.5%), and radiological signs of root resorption were detected in 9/57 teeth (15.8%). PRV was positive in 54/57 teeth (94.7%). Surgical duration and PRV failure were significantly associated with high incidences of root resorption. Mature teeth autotransplantation with EORER yielded similar results to immature teeth autotransplantation and is a feasible treatment option. Long surgery and failed revascularization increased root resorption rates. More factors should be evaluated in larger trials with longer observation periods.

Long-Term Survival Rate of Autogenous Tooth Transplantation: Up to 162 Months

Background and Objectives: The purpose of this study is to observe the usefulness of autogenous tooth transplantation by examining the cumulative survival rate according to the period of auto-transplanted teeth as pre-implant treatment. Materials and Methods: This study was conducted on 111 patients who visited Kyungpook National University Dental Hospital and underwent autogenous tooth transplantation between November 2008 and January 2021 (about 13 years). The cumulative survival rate of autogenous tooth transplantation according to the causes of extraction of the recipient tooth (caries, periapical lesion, crack, crown fracture, periodontitis) and condition of opposing teeth (natural teeth vs. fixed prosthesis). The cumulative survival rate of autogenous tooth transplantation according to the age (under 30 vs. over 30) was also investigated and it was examined whether there were any differences in each factor. Results: The average follow-up period was 12 months, followed by a maximum of 162 months. The 24-month cumulative survival rate of all auto-transplanted teeth was 91.7%, 83.1% at 60 months and the 162-month cumulative survival rate was 30.1%. There were no statistical differences between the causes of extraction of the recipient's teeth, differences in the condition of the opposing teeth, and differences under and over the age of 30. Conclusions: The survival rate of autogenous tooth transplantation appears to be influenced by the conditions of the donor tooth rather than the conditions of the recipient tooth. Although autogenous tooth transplantation cannot completely replace implant treatment, it is meaningful in that it can slightly delay or at least earn the time until implant placement is possible.

Immediate Tooth Autotransplantation with Root Canal Filling and Partially Demineralized Dentin/Cementum Matrix into Congenital Missing Tooth Region

This clinical report describes immediate tooth auto-transplantation with an autograft of partially demineralized dentin/cementum matrix (pDDM), based on an orthodontic treatment plan for a 16-year-old male patient with a congenital missing tooth (#45). First, vital teeth (#14, #24) were extracted, and root canal filling (#14) was immediately performed with the support of a fixation device. Simultaneously, the tooth (#24) was crushed in an electric mill for 1 min, and the crushed granules were partially demineralized in 2% HNO₃ solution for 20 min as the graft material. Next, the donor tooth was transplanted into the created socket (#45), and stabilized using an enamel bonding agent. The wet pDDM was loaded into the location of the congenital missing tooth, and the flap was repositioned. The bonding agent for stabilization was removed at 28 days, and also small contact points between the transplanted tooth and the upper premolar (#14) were added using photopolymerizable composite resin. X-ray photos were taken sequentially, and there were no postoperative complications. The radiographic images showed that the periodontal ligament space and alveolar ridge line could be observed at 18 months. The pDDM was harmonized with the mandible, and the remodeled bone-like shadow was observed in the graft region. We concluded that immediate tooth transplantation with root canal fillings and autogenous pDDM may be a valuable alternative to dental implanting or bridge formation for patients with a congenital missing tooth, followed by orthodontic treatment.

The enhanced conservation of vital pulp and apical tissues by the application of crown rotation surgery for inversely impacted central incisors: a follow-up analysis of two patients over four years

AIM

To describe a novel surgical method (crown rotation surgery) to manage inversely impacted central incisors with immature roots.

SUMMARY

Two young patients each presented with an inversely impacted maxillary central incisor. To protect the apical tissues, the two impacted incisors were rotated downwards to a relatively normal position without extraction from their bony sockets. After crown rotation surgery, spontaneous eruption, continuous root development, and periodontal healing of the rotated incisors were observed. The pulp retained vitality and blood flow was normal. Moreover, there were no obvious signs of pulp canal obliteration (PCO), as indicated by Cone Beam Computed Tomography (CBCT) imaging.

KEY LEARNING POINTS

• By optimising protection of the vital pulp and apical tissues, crown rotation surgery represents a minimally invasive, conservative, and practical surgical technique for treating inversely impacted incisors with developing roots. • In contrast to existing surgical methods, crown rotation surgery may avoid certain complications, including PCO and abnormal or arrested root development.

Does Root Development Status Affect the Outcome of Tooth Autotransplantation? A Systematic Review and Meta-Analysis

Background: Tooth autotransplantation is defined as the surgical repositioning of an autogenous tooth in another surgical site within the same individual. Aim: The aim of this research was to analyze the outcome of tooth transplantation using immature donor teeth compared with closed apex teeth and to compare differences between donor tooth positions on the arch. Methods: Electronic and manual literature searches were performed in different databases, including the National Library of Medicine (MEDLINE), EMBASE (OVID), Cochrane Central (CENTRAL), and the digital library of the Universitat Internacional de Catalunya (UIC University) from 1978 to March 2021. Studies were selected when they fulfilled the following criteria: only human prospective clinical studies, minimum sample size of 10 patients, minimum follow-up of 1 year, studies reporting or with at least deducible data on survival rates, immediate tooth autotransplantation with completed or incomplete root formation, and publications in the English language. A meta-analysis of random effects was developed to estimate the global effect measure of the survival rate, success rate, and root resorption involving the total sample, as well as open- and closed-apex groups. Results: Twenty-four articles were eligible for analysis. The Cohen’s kappa corresponding to this review was 0.87, and the risk assessment was considered low–moderate for the included studies. Overall survival and success rates were 95.9% and 89.4%, respectively, with a mean follow-up of 4 years and an overall mean age of 25.2 ± 12.3 years. Closed apex teeth showed a survival rate of 3.9% lower than that of open apex teeth. Higher complication rates were found for both inflammatory external root resorption and replacement root resorption in the closed-apex group, without reaching statistical significance. Conclusions: Tooth autotransplantation is a viable treatment alternative, regardless of the apical condition, with high survival and success rates after a mean follow-up of 4 years. Open-apex donor teeth could be considered the gold-standard option, showing lower complication rates when compared to closed-apex donor teeth. Future randomized controlled clinical studies are needed to examine the long-term prognosis of this technique.

Root Membrane Replantation as an Alternative Technique for the Socket Preservation

Background and Overview. Socket shield is a technique that allows the maintenance of tissue volumes. In the reported clinical case, the replantation of the buccal root fragment mistakenly extracted during a socket shield surgery is performed. We present a follow-up to 5 years with an unexpected healing.Case Description. An 88-year-old patient underwent an immediate loading implant placement associated with the replantation of the mistakenly extracted root fragment. The shaping of the fragment was performed extraorally, and the replantation was done so that the fragment protruded above the crest margin.Conclusions and Practical Implications. The 5-year follow-up shows an uneventful healing of the implant. At 48 months, postoperative CBCT exam reports images compatible with the regeneration of the bone over the portion of root that protruded over the margin. The outcome suggests clinical implications, as the opportunity to easily shape the fragment extraorally and replant sound portion of the root (not necessary the buccal) in buccal socket with bone defect.

Efficacy of i-PRF in regenerative endodontics therapy for mature permanent teeth with pulp necrosis: study protocol for a multicentre randomised controlled trial

BACKGROUND

Dental pulp necrosis, a common health problem, is traditionally treated with root canal therapy; however, it fails in restoring the vitality of damaged pulp. Most studies regarding regenerative endodontic therapy (RET) are limited to the treatment of immature necrotic teeth. Given that injectable platelet-rich fibrin (i-PRF) has shown great potential in regenerative medicine as a novel platelet concentration, this study is designed to explore whether i-PRF can serve as a biological scaffold, extending the indications for RET and improving the clinical feasibility of RET in mature permanent teeth with pulp necrosis.

METHODS

This is a randomised, double-blind, controlled, multicentre clinical trial designed to evaluate the clinical feasibility of RET for mature permanent teeth with pulp necrosis and to compare the efficacy of i-PRF and blood clots as scaffolds in RET. A total of 346 patients will be recruited from three centres and randomised at an allocation ratio of 1:1 to receive RET with either a blood clot or i-PRF. The changes in subjective symptoms, clinical examinations, and imaging examinations will be tracked longitudinally for a period of 24 months. The primary outcome is the success rate of RET after 24 months. The secondary outcome is the change in pulp vitality measured via thermal and electric pulp tests. In addition, the incidence of adverse events such as discolouration, reinfection, and root resorption will be recorded for a safety evaluation.

DISCUSSION

This study will evaluate the clinical feasibility of RET in mature permanent teeth with pulp necrosis, providing information regarding the efficacy, benefits, and safety of RET with i-PRF. These results may contribute to changes in the treatment of pulp necrosis in mature permanent teeth and reveal the potential of i-PRF as a novel biological scaffold for RET.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04313010 . Registered on 19 March 2020.

Pre- and peri-operative factors influence autogenous tooth transplantation healing in insufficient bone sites

Background

The amount of bone remaining at the transplant site for autogenous tooth transplantation can facilitate successful healing. Therefore, this retrospective study evaluated the factors influencing the healing of 50 successful autogenous tooth transplantations with insufficient bone support at the transplanted site without a bone graft.

Methods

The factors were classified as pre- and peri-operative factors, and the healing outcomes were clinical and radiographic observations. The factors were statistically analyzed using the chi-square test to identify correlations between the pre- and peri-operative factors and the clinical and radiographic outcomes. The T-test or one-way analysis of variance was used to compare the percent bone change in each factor.

Results

The results indicated that gingival healing was delayed in the intra-arch transplantations, and pulp obliteration was seen earlier when transplanted in the maxilla. Patients under 18-years-old demonstrated a greater percent bone change than the over 18-year-old patients, while the peri-operative variables did not have a relationship with clinical healing and the amount of bone change over 12 months. Furthermore, the percent bone change significantly increased during the first three months.

Conclusions

In conclusion, pre-operative factors, age and transplant site, influenced the healing rate of autogenous transplanted teeth. In contrast, the peri-operative factors were not related with the clinical and radiographic outcomes. Generating the least trauma to the periodontal ligament cells is the most important concern.

Status of the alveolar bone after autotransplantation of developing premolars to the anterior maxilla assessed by CBCT measurements

Background/Aims

Autotransplantation of developing premolars is an established treatment to replace missing teeth in the anterior maxilla in growing patients with a reported success rate of over 90%. The normal shape of the alveolus is observed after transplantation, but data on the presence and amount of alveolar bone after healing has not been previously reported. The aim of this study was to look for potential differences in alveolar bone dimensions between sites where autotransplanted premolars replaced missing incisors and control sites of contralateral incisors.

Material/Methods

There were 11 patients aged between 10 and 12 years five months (mean age: 10 years and 7 months) who underwent autotransplantation of a premolar to replace a central incisor. Cone Beam Computed Tomography (CBCT) performed at least 1 year after transplantation served to evaluate bone at sites of autotransplanted premolars and controls (contralateral maxillary central incisor). The thickness of the labial bone, plus the height and width of the alveolar process were measured on scans and compared at transplant and control sites.

Results

Mean thicknesses of the labial bone at the transplant and control sites were 0.78 mm and 0.82 mm respectively. Mean alveolar bone height was 15.15 mm at the transplant sites and 15.12 mm at the control sites. The mean marginal thickness of the alveolus was 7.75 mm at the transplant sites and 7.98 mm at the control sites. Mean thicknesses of the alveolus for half of its vertical dimension at the transplant and control sites were 7.54 mm and 8.03 mm, respectively.

Conclusion

The mean values of bone thickness, width and height of the alveolar process at sites of transplanted premolars were comparable to the mean values for the control incisors. Successful autotransplantation of developing premolars to replace missing central incisors allowed preservation of alveolar bone in the anterior maxilla.

Use of computer-aided three-dimensional prototyping to surgically assist in tooth autotransplantation

Autotransplantation is a surgical technique in which a donor tooth belonging to the same individual is repositioned into a surgically prepared socket or site of previous tooth extraction. It is beneficial in patients with teeth affected by agenesis, trauma, significant caries, and in teeth in a non-restorable condition or prognostically poor due to other pathology. It is particularly useful in paediatric patients, as properly transplanted teeth have a vital periodontium that allows for continuous growth and functional adaptation leading to preservation of the alveolar ridge. Technological advances in rapid prototyping combined with three-dimensional (3D) computed tomography (CT) have the ability to revolutionise autotransplantation. Preoperative planning for atraumatic extraction of the donor tooth and precise preparation of the recipient site with a rapid prototyped surgical template of the donor tooth considerably reduces the extra-alveolar time, and also reduces manipulation of the root sheath and periodontal ligament, and related trauma. This case series demonstrates the efficient and successful autotransplantation of various types of teeth with the use of a rapid prototyped surgical template produced from 3D CT. The use of this technology is expected to refine the surgical technique and improve treatment outcomes.

Mid-Term outcomes and periodontal prognostic factors Of autotransplanted third molars: A Retrospective Cohort Study

BACKGROUND

Tooth autotransplantation is a valid method for replacing non-restorable teeth. This study aimed to assess mid-term survival and success of autotransplanted third molars and the clinical periodontal parameters and factors predicting successful periodontal attachment apparatus regeneration.

METHODS

In total, 36 patients who had undergone extraction and subsequent autotransplantation of 36 third molars using virtual planning and computer-aided rapid prototyping models by an oral surgeon and endodontist were eligible. Probing pocket depth (PPD), gingival recession (REC), clinical attachment level (CAL), pulpal and periapical healing, root resorption, and radiographic bone loss (RBL) were evaluated. Additionally, a questionnaire evaluated patient-reported outcomes.

RESULTS

The mean age of the participants was 30.2 years with a mean follow-up duration of 29.42 ± 14.56 months. The overall survival and success rates were 97.2% and 91.7%, respectively. No statistically significant differences were found in success and survival rates between open and closed apex groups or between compromised and intact buccal bone groups. No signs of pulp necrosis were found in the open apex group. Progressive replacement resorption was detected in one closed apex case. The mean PPD was 2.7 ± 0.45 mm for all transplanted teeth. REC was 0.13 mm higher in transplanted teeth than in previous hopeless teeth. CAL changes were neither clinically relevant (-0.17 ± 0.66 mm) nor statistically significant. The reported patient satisfaction was high.

CONCLUSIONS

Autotransplantation of third molars is a predictable treatment method, with a 2.5-year cumulative tooth survival and success of 97.2% and 91.7%, respectively, which were not influenced by recipient site integrity or root development.

Intentional replantation and Biodentine root reconstruction. A case report with 10-year follow-up

AIM

To describe the innovative use of intentional replantation for Biodentine root reconstruction of a previously treated immature maxillary central incisor with vertically extended crown root fracture and root detachment.

SUMMARY

In the present case, the intentional replantation of a failing, previously treated maxillary central incisor with a vertical crown/root fracture in a 12-year-old male patient is reported. The gross extrusion of gutta-percha points beyond the apex and the pre-existing extensive, trauma related, distal cervical dentinal detachment justified the intentional replantation treatment plan as an option for tooth retention. After controlling the infection by oral administration of antibiotics, the immature tooth was extracted atraumatically and kept in gauze embedded with tooth replantation medium. The apical third of the immature fractured tooth was treated with ultrasonics and an MTA plug (MTA Angelus White, Londrina, Brazil). The distal cervical dentinal root defect was reconstructed with Biodentine (Septodont, St. Maur-des-Fosses, France). The tooth was reinserted and stabilized to the adjacent teeth for 2 weeks. The total extraoral time before replantation was 25 min. In the 10 years since the initial trauma (9 years after the intervention) radiographic and clinical evaluation revealed uneventful healing of the periapical lesion, normal mobility and no detectable signs of external replacement resorption.

KEY LEARNING POINTS

Intentional replantation may provide a viable treatment alternative in cases of severe complicated crown/ root fractures Biodentine may be useful in the reconstruction of external root defects in crown root fractured traumatic dental injuries.

The orthodontic bonding properties of human enamel after cryopreservation

The aim was to investigate the effect of cryopreservation on the enamel bonding properties of orthodontic brackets. Sixty-six human premolars were randomly allocated to a control group or a cryopreserved group. Conventional stainless-steel orthodontic brackets were bonded with a light cure adhesive on the buccal side of the premolars. The shear bond strength (SBS) was determined at a crosshead speed of 1 mm/min. The SBS and adhesive remnant index (ARI) were evaluated respectively by an independent samples t test and Fisher's exact test (α≤0.05). The mean failure load was lower in the cryopreserved group. However, this difference in SBS was not significant (p=0.443). In both groups, the ARI mostly indicated a failure at the enamel-adhesive interface. The mean ARI scores for both groups were not significantly different (p=0.099). Within the limitations of this macro bond strength testing, it can be concluded that cryopreservation does not significantly affect the bonding properties of enamel.

A retrospective analysis of autotransplanted teeth including an evaluation of a novel surgical technique

OBJECTIVES

To assess survival rates and frequency of complications for immature and mature autotransplanted teeth after at least 1 year in function.

MATERIALS AND METHODS

All consecutive patients who had undergone tooth autotransplantation between 2000 and 2018 were invited to a clinical and radiographic follow-up examination. First, survival rates were calculated on the basis of a phone inquiry. A clinical follow-up examination allowed for the calculation of the success rate, i.e., absence of any potentially adverse clinical and radiographic findings of the autotransplanted teeth. Moreover, the effect of demographic, dental, and surgical variables on survival/success was analyzed statistically.

RESULTS

Thirty-eight teeth in 35 patients were transplanted during the study period. Three teeth in 3 patients were excluded due to missing records. All other patients were successfully contacted and interviewed by phone. Out of these 35 transplants, 32 were still in function, and 3 had been extracted, yielding a 91.4% survival probability after a median follow-up of 3.4 years. Of the 32 teeth qualifying for the success analysis, 20 (62.5%) showed absence of potentially adverse findings, while 3 (9.4%) required root canal treatment (RCT). Out of the 9 mature, root-end resected transplants, 4 exhibited ongoing pulp canal obliteration, all with a single root canal. Postoperative and potentially adverse findings or failures were found more frequently in the group of mature transplants (55.6%) than immature transplants (30.4%) and for molars (72.7%) than premolars (17.6%) or canines (25%). None of the potential predictors had a statistically significant effect on survival or success.

CONCLUSION

Autotransplanted teeth yielded a satisfying midterm survival rate regardless of their stage of development. An additional, extraoral root-end resection of mature transplants may lead to rates of revascularization and postoperative pulp canal obliteration higher than the data reported on unmodified mature transplants.

CLINICAL RELEVANCE

Extraoral root-end resection of mature teeth shows promising outcomes for transplants especially with a single root canal and uncomplicated root morphology.

Ectopic eruption of the second premolar: an analysis of four different treatment approaches

PURPOSE

Ectopic second premolars may lead to impaction and loss of space in the jaws, and in rare cases even to resorption of the first permanent molar. The aim of this study was to analyse different treatment strategies of ectopic second premolars and if possible give guidelines on when to favour different treatment approaches.

MATERIALS AND METHODS

The study was a retrospective, non-randomised, outcome analysis of treatment on 41 ectopic second premolars in 37 patients (24 females and 13 males). In all cases oral examination, radiographs (pre-, peri-, and post) and full medical history were obtained. The treatment options included: (a) spontaneous eruption, (b) spontaneous eruption + extraction of primary tooth, (c) surgical exposure, (d) surgical uprighting, and (e) surgical uprighting + orthodontic extrusion. For evaluation each tooth was scored according to: (1) stage of root development, (2) distance between edges of the premolar and first permanent molar, (3) depth of impaction, (4) inclination, (5) horizontal position of the tooth. The level of significance was set to 5%.

RESULTS

Only mild cases of ectopic second premolars are self-correcting. Based on the position of the tooth in the jaw different treatment options may be chosen, these may include: extraction of primary predecessor (impaction depth < 5 mm, inclination < 55°), surgical exposure of tooth germ (impaction depth < 5.5 mm, inclination < 95°) or surgical uprighting (impaction depth > 5.5 mm with no inclination limit).

CONCLUSION

If there is no sign of self-correction after a short observation period, it is important to consider active treatment to help guiding the tooth into the correct eruption pathway.

Orthodontic management of patients with congenitally missing permanent teeth

Dental agenesis is one of the most common developmental anomalies in humans. It occurs as part of a genetic syndrome or as an isolated sporadic or familial finding. Third molars, second mandibular premolars and maxillary lateral incisors are the most frequently targeted teeth of the permanent dentition. Clinically, patients with congenitally missing permanent teeth seeking treatment present with unesthetic diastemas, midline deviation and tilting of adjacent teeth in the edentulous areas. The impact of tooth agenesis reflects on esthetics, function, psychological and social well-being of the individuals affected. Orthodontics can contribute to the treatment plan selected by rearranging the present teeth so as to open spaces for prosthetic restorations or close spaces by reshaping teeth if needed. Following orthodontic space opening/maintaining, the usual alternatives involve single implants, two-(cantilever) or full coverage(cantilever) prostheses. Less frequently, the treatment modality of autotransplantation is proposed with a good esthetic result but feasible only in young patients where the roots of the premolars are still developing. In orthodontic space closure, treatment is accomplished sooner without waiting for the completion of growth of the patient. Depending on various factors such as the malocclusion, the dento-skeletal profile, the smile line, the space requirements, the teeth missing, the periodontal issues, the age of the patient and any financial issues, the clinician will determine the most appropriate treatment approach. The final esthetic and functional result should resemble an intact natural dentition.

Autotransplantation of mature impacted tooth to a fresh molar socket using a 3D replica and guided bone regeneration: two years retrospective case series

Background

The aim of this study was to evaluate the clinical outcome of autotransplantation of mature third molars to fresh molar extraction sockets using 3D replicas.

Methods

Ten patients underwent teeth autotransplantation with or without GBR. We observed the mobility, percussion, radiography examination, the probing depth and the masticatory function of the transplanted teeth during 2 years following up, which were transplanted into fresh molar sockets by using 3D replicas, and GBR when it is necessary.

Results

The average extra-oral time of donor tooth had been shortened to 1.65 min when used the 3D replica. Some probing depth of the transplanted tooth were deeper than 3 mm at 4 or 5 weeks temporarily. And one patient felt slight sensitive when chewing with soft food at 4 weeks, then disappeared. The clinical examination of the autotransplantation teeth during 1 year follow-up showed no sign of failure.

Conclusions

The tooth autotransplantation using 3D replica with or without GBR is an effective method which can reduce the extra-oral time of the donor teeth and may result in less failure.

Survival probability of dental autotransplantation of 366 teeth over 34 years within a hospital setting in the United Kingdom

INTRODUCTION

The purpose of this retrospective study was to evaluate 34 years' experience of autotransplantation of teeth during orthodontic treatment.

METHODOLOGY

Treatment was completed at Queen Mary's Hospital, Sidcup, Kent, UK, during the period 1969-2003. A total of 366 teeth were transplanted in 314 patients.

RESULTS

Canines totalled 78 per cent of all autotransplanted teeth; mean age of patient was 19.4 years. Survival probability for the first 5 years post-autotransplantation was 95 per cent, 94 per cent for the subsequent 5 years, and 88 per cent after 15 years. The maximum observation period was 34 years, the median was 2.0 years, and the mean was 3.51 (standard deviation = 3.68) years. Of the observed teeth, 10 failed and these were lost due to unsuccessful periodontal ligament regeneration and persistent mobility grade III (or greater). Apical pathology was observed in 16 per cent of all autotransplanted teeth. In 79 per cent of this subgroup, apical pathology was evident in the first 3 years post-operatively. Seventy per cent of all external resorption also occurred within the first 3 years. Internal resorption was rare but its occurrence was mostly observed between the second and sixth year post-transplantation. A minority of autotransplanted teeth [14 per cent (n = 51)] needed root canal therapy, and this was completed within the first 6 months post-transplantation.

CONCLUSIONS

Autotransplantation can be a justified procedure with good survival probability. It can be considered an alternative to other treatments, such as prosthodontic replacement of teeth.

Effects of mechanical force application on the developing root apex in rat maxillary molars

OBJECTIVES

We aimed to investigate the effects of mechanical force application on the developing root apex in vivo.

DESIGN

Mechanical force was applied on the maxillary first molars of Sprague-Dawley rats at postnatal day 21 for 1, 3, 5, and 7 days to induce tooth movement. We observed the developing root apex of the mesial root of first molar by using micro-focus X-ray computed tomography, histological staining, immunohistochemistry and in situ hybridization to analyze apical cell proliferation and gene expression. Moreover, the force was released after 3 and 7 days of tooth movement, and root apical morphology at postnatal day 35 was subsequently observed.

RESULTS

After 1 and 3 days of tooth movement, root apical morphology was altered by increasing immune-reactivity of laminin in the forming periodontal ligament. After 7 days of tooth movement, the root length decreased significantly with bending root apex, decreased cell proliferation and altered gene expression in developing root apex. At postnatal day 35, apical morphology showed no obvious abnormality when the force was released after 3 days of tooth movement, whereas root apical bending was not rescued when the force was released after 7 days.

CONCLUSIONS

Relatively short-term force application had no obvious adverse effects on the developing root apex. However, relatively long-term force application altered root apex by affecting Hertwig's epithelial root sheath morphology and apical cellular behavior.

Use of CBCT Guidance for Tooth Autotransplantation in Children

Tooth autotransplantation (TAT) offers a viable biological approach to tooth replacement in children and adolescents. The aim of this study was to evaluate the outcome of the cone-beam computed tomographic (CBCT)–guided TAT compared to the conventional TAT protocol and to assess the 3-dimensional (3D) patterns of healing after CBCT-guided TAT (secondary aim). This study included 100 autotransplanted teeth in 88 patients. Each experimental group consisted of 50 transplants in 44 patients (31 males and 19 females). The mean (SD) age at the time of surgery was 10.7 (1.1) y for the CBCT-guided group. This was 10.6 (1.3) y for the conventional group. The mean (SD) follow-up period was 4.5 (3.1) y (range, 1.1 to 10.4 y). Overall survival rate for the CBCT-guided TAT was 92% with a success rate of 86% compared to an 84% survival rate and a 78% success rate for the conventional group ( P > 0.005). The following measurements were extracted from the 3D analysis: root hard tissue volume (RV), root length (RL), apical foramen area (AFA), and mean and maximum dentin wall thickness (DWT). Overall, the mean (SD) percentage of tissue change was as follows: RV gain by 65.8% (34.6%), RL gain by 37.3% (31.5%), AFA reduction by 91.1% (14.9%), mean DWT increase by 107.9% (67.7%), and maximum DWT increase by 26.5% (40.1%). Principal component analysis (PCA) identified the mean DWT, RV, and maximum DWT as the parameters best describing the tissue change after TAT. Cluster analysis applied to the variables chosen by the PCA classified the CBCT group into 4 distinct clusters (C1 = 37.2%, C2 = 17.1%, C3 = 28.6%, C4 = 17.1%), revealing different patterns of tissue healing after TAT. The CBCT-guided approach increased the predictability of the treatment. The 3D analysis provided insights into the patterns of healing. CBCT-guided TAT could be adopted as an alternative for the conventional approach. (Clinical trial center and ethical board University Hospitals, KU Leuven: S55287; ClinicalTrials.gov Identifier: NCT02464202)

Fracture resistance of simulated immature teeth treated with a regenerative endodontic protocol

This study aims to evaluate fracture resistance of simulated immature teeth after treatment with regenerative endodontic procedure (REP) using tricalcium silicate cements (TSCs) as cervical plugs. Bovine incisors were sectioned to standard crown/root ratio. Pulp tissue was removed and canals were enlarged to a standardized diameter. Teeth were then treated with a REP protocol consisting of NaOCl and EDTA irrigation, intracanal medication with triple-antibiotic paste for 14 days followed by a TSC cervical seal and composite restoration. Teeth were divided into groups according to the material used; Mineral-Trioxide-Aggregate (MTA), Biodentine, TotalFill. Teeth filled with guttapercha (GP) and intact teeth served as controls. All teeth subjected to an increasing compressive force (rate of 0.05 mm/s at a 45° angle to the long axis of the tooth) until fracture. All treated teeth exhibited significantly lower resistance to fracture compared to the intact teeth but no difference was found between the TSC groups (Kruskal-Wallis, Dunn’s multiple comparison, p < .05). TSCs applied at the cervical area of simulated immature teeth treated with REP did not reinforce fracture resistance.

Outcome of Autotransplantation of Mature Third Molars Using 3-dimensional-printed Guiding Templates and Donor Tooth Replicas

Autotransplantation exhibits a number of advantages compared with other treatment options (ie, dental implants or fixed partial prostheses), such as greater resistance to occlusal loading, maintenance of the periodontal ligament and surrounding bone, and the potential for better esthetics. The aim of this study was to determine clinical outcomes for autotransplanted teeth with complete root formation using 3-dimensional-printed guiding templates and tooth replicas. Twenty-seven third molars with completely formed roots were autotransplanted. Each donor tooth and recipient site were examined clinically and radiographically (periapical radiographs). A selective cone-beam computed tomographic scan was taken of each donor tooth and recipient site. The images of the selected donor teeth were segmented and saved as stereolithography files. Similar to virtual planning of dental implants, correct angulation, rotation, and accurate positioning of the donor teeth were predefined using the stereolithography files. According to the virtually defined positions and dimensions of the donor teeth, 3-dimensional guiding templates and donor tooth replicas were printed. All autotransplantations were performed according to 1 treatment protocol and surgical technique. In 22 of the 24 transplanted teeth, no inflammation occurred during the healing period. At 2 years, no pathologic radiolucency or tooth resorption was observed in the 22 donor teeth. The autotransplanted teeth fulfilled the success criteria in 22 cases for a 91.7% success rate. Digital planning could potentially provide an accurate alternative to current autotransplantation techniques.

Influence of Extraoral Apicoectomy on Revascularization of an Autotransplanted Tooth: A Case Report

Autotransplantation is considered a standard procedure with a poorer prognosis for mature than for immature teeth. In this case report, the root tip of an almost fully developed tooth was resected during autotransplantation to fit into a deficient recipient site. As a positive side effect, the apical foramen was enlarged, with potential improvement of the probability of revascularization. Clinical and radiologic follow-up examinations up to 18 months indicated revascularization and uneventful periodontal regeneration and thus successful autotransplantation. This case supports the hypothesis that intraoperative apicoectomy can improve the prognosis for revascularization of mature autotransplanted teeth. Further prospective controlled clinical studies are needed to confirm this innovative surgical approach.

Autotransplantation of teeth with incomplete root formation: a systematic review and meta-analysis

OBJECTIVES

The objective of this systematic review and meta-analysis was to determine the rates of survival and success and the complications related to autotransplantation of teeth with incomplete root formation. Additionally, we attempted to identify the prognostic factors that influence the outcome of tooth autotransplantation.

MATERIALS AND METHODS

A literature search for all data published until July 2016 was conducted. Inclusion and exclusion criteria were specified. Risk of bias was assessed with the Newcastle checklist. Meta-analysis was performed by using the DerSimonian-Laird random effect model. The 1-, 5-, and 10-year survival rates and the weighted estimated survival, success, and complication rates per year were calculated.

RESULTS

Thirty-two studies were included for analysis. The survival rates reported after 1, 5, and 10 years were 97.4, 97.8, and 96.3%, respectively. The annual weighted estimated survival rate (98.2%), success rate (96.6%), and complication rates in terms of ankylosis (2.0%), root resorption (2.9%), and pulp necrosis (3.3%) were analyzed. No firm conclusions could be drawn with respect to the prognostic factors due to insufficient evidence of high quality.

CONCLUSION

The survival and success rates of autotransplantation of teeth with incomplete root formation were high (> 95%), with a low rate of complications (< 5%).

CLINICAL RELEVANCE

Current evidence from the literature on autotransplantation of teeth with incomplete root formation shows favorable survival and success rates and low complication rates, indicating it is a reliable treatment option.

Autotransplantation and Orthodontic Treatment after Maxillary Central Incisor Region Trauma: A 13-Year Follow-Up Case Report Study

The anterior maxilla is the most prone region to the trauma during childhood, and tooth loss sometimes happens due to trauma. Replacing the missing teeth has always been one of the dentists' challenges in children and adolescents, since their dentofacial growth is not complete. Autotransplantation of mandibular premolars with two-thirds or three-quarters of root formation provides the best prognosis for the tooth survival. This case report describes the management of a 10-year-old boy suffering a severe dental injury who received the autotransplantation of the premolars from mandible to restore the space caused by trauma in maxillary central incisor region and a 13-year follow-up of the autotransplantation.