Outcomes of apexification in immature traumatised necrotic teeth and risk factors for premature tooth loss: A 20-year longitudinal study

BACKGROUND/AIM

To evaluate the long-term survival of immature traumatized incisors with pulp necrosis and apical periodontitis after endodontic treatment with two apexification techniques (calcium hydroxide apexification and MTA-apical plug) and to identify major factors affecting the survival of these teeth.

MATERIALS AND METHODS

Records of 2400 children and adolescents were screened for presence of traumatic dental injuries to immature incisors where endodontic treatment with the two apexification techniques was performed during January 2003 and December 2022, compared to a control group of mature teeth treated with conventional endodontic techniques. The studied variables were age; sex; apexification technique, presence of luxation and hard tissue injuries; preoperative root development stage (RDS), preoperative and postoperative periapical index (PAI), the time-point for tooth loss, and overall survival time in years. Kaplan-Meier estimates were used to graphically present the survival functions and Cox proportional hazard model to calculate hazard ratios (HR, 95% CI).

RESULTS

The median survival time was 10 years for calcium hydroxide apexification, 16.1 for MTA-apexification, for luxation injuries other than intrusions and avulsions 15.5 years, for intrusions 12.5 years and for avulsions 6.8 years. The variables with significant negative impact on tooth survival were calcium hydroxide apexification, avulsion and postoperative PAI 3-5. No significant relationships were found for the variables MTA apexification, concussion; subluxation; lateral luxation; extrusion, intrusion, hard tissue injuries, preoperative RDS and PAI scores and postoperative PAI 1-2. After adjustment, the risk for premature tooth loss was 13.5 times higher in calcium hydroxide apexification, approximately 2 to 4 times higher in PAI 3-5, and 5.6 times higher in avulsions.

CONCLUSIONS

Calcium hydroxide apexification, avulsion, and postoperative PAI 3-5 were identified as prognostic variables with significant negative impact on the risk for premature tooth loss.

Risk of ankylosis of avulsed teeth immediately replanted or stored under favorable storage conditions before replantation: A long-term clinical study

BACKGROUND/AIM

There are few long-term clinical follow-up studies on human teeth replanted immediately or after storage in a suitable storage medium prior to replantation. This study aimed to assess the risk of ankylosis in avulsed human teeth replanted immediately or after storage in physiological media for a short time.

MATERIAL

Data from 116 patients with 145 replanted avulsed permanent teeth were selected from a comprehensive dental trauma database in Copenhagen University Hospital. The following teeth were selected: Group 1 comprised 36 teeth replanted immediately (dry time <6 min; wet time <6 min). Group 2 comprised 61 teeth replanted after physiologic storage media (saliva and saline) (dry time <6 min; wet time >5 min; wet time ranged from 7 to 170 min, and mean wet time was 59 min). Group 3 (control) included 48 teeth replanted after dry storage (dry time > 60 min).

METHOD

Clinical and radiographic registrations were carried out according to a standardized protocol; follow-up ranged from 7 months to 23 years. Ankylosis was diagnosed by percussion test and radiographs and related to the conditions prior to replantation and stage of root development.

RESULTS

The overall risk of ankylosis was 17.2% [95% CI: 4.61; 29.79] for immediately replanted teeth, 55.3% [95% CI: 42.54; 68.00] for teeth stored in physiologic media before replantation, and 85.7% [95% CI: 75.70; 95.73] for teeth stored dry more than 1 h. Mature teeth showed a significantly higher risk of ankylosis than immature teeth.

CONCLUSION

This clinical long-term study has verified earlier experimental studies showing that immediate reimplantation has the lowest risk of ankylosis. Physiologic storage media are good alternatives that also reduce the risk of ankylosis compared to dry storage, where ankylosis is more likely although not always seen. Mature teeth are significantly more likely to develop ankylosis.

Evaluating the effect of strontium ranelate and photobiomodulation on cementogenic and osteogenic differentiation of buccal fat pad-derived stem cells: An in vitro study

This study aimed to analyze the impact of strontium ranelate (Str), photobiomodulation (PBM), or their combination of the proliferation, osteogenic differentiation, and cementogenic differentiation of buccal fat pad-derived stem cells. BFPdSCs were exposed to one of the following interventions: (1) PBM (660 nm), (2) PBM (660 nm) + Str, (3) PBM (880 nm), (4) PBM (880 nm) + Str, (5) Str. All study groups had significantly higher osteogenic differentiation than the control group (p < 0.05), and no significant difference existed between the 660 and 808 nm groups (p = 0.97). Compared to the Str group, 660 nm and 880 nm group samples had significantly lower osteogenic differentiation (p < 0.0001), while other groups did not show a significant difference. Regarding cementogenic differentiation, the 660 nm group showed higher values than the 808 nm group (p < 0.01). Compared with the Str group, 660 nm, 660 nm + Str, and 808 nm + Str groups showed significantly higher gene expression (p < 0.05). In the case of osteogenic differentiation, although photobiomodulation alone had a lower inducing effect than strontium ranelate, combining 808 nm diode lasers and strontium ranelate may provide the best results. Moreover, using a 660 nm diode laser and exposing stem cells to strontium ranelate can be the most effective approach to induce cementogenic differentiation.

Displacement Injuries: Assessment and Management

This paper aims to aid clinicians in the assessment and immediate management of dental trauma displacement injuries to permanent teeth. Long term sequelae, the impact of such injuries, and the evidence-base for managing these are discussed.Clinical cases are provided to illustrate management challenges and highlight where further evidence-based guidance is needed. The role of the general dental practitioner in the immediate management and follow-up of traumatic dental injuries is outlined and sequelae, worthy of potential referral, described.

Avulsion Injuries: Assessment and Management

Avulsion injuries, though relatively uncommon, are one of the most serious of dentoalveolar injuries. Replantation at the scene of the incident is almost always the treatment of choice whenever possible. This paper outlines a step-by-step approach for the management of avulsion injuries, including a splinting protocol. This aims to support general dental practitioners in feeling more confident with managing these injuries.

Parents' knowledge of emergency management of avulsed permanent teeth in children and adolescents in the State of Qatar: a questionnaire cross-sectional study

PURPOSE

To elucidate the level of parental knowledge in Qatar regarding the management of avulsed teeth.

METHODS

A self-administered questionnaire was completed by 400 parents attending their children's routine dental appointments. The questionnaire comprised of items on sociodemographics, parents' prior knowledge on management of avulsion, parents' willingness to replant avulsed teeth at the site of injury, and parents' opinion as to the best format for future parental education on the management of dental trauma. Univariate and multivariate logistic regressions were employed to assess the association between sociodemographic status and knowledge in the management of avulsion.

RESULTS

The overall mean score of parents' knowledge was (23%). Only 23.3% (n = 93) of parents thought that it was possible to reinsert an avulsed permanent tooth. Out of those, only 12.9% (n = 12) indicated willingness to reinsert the tooth back into its socket, while 48.4% (n = 49) indicated that an avulsed tooth should be stored using physiological media. Less than one third (27.8%) indicated that they would seek professional help within 30 min. Males were less likely to give favourable answers when compared to females (OR = 0.43, 95% CI = 0.22-0.84). Age groups "31-40" years and "41-50" years were more likely to give favourable answers when compared to 20-30 years age group (OR = 2.8, 95% CI = 1.05-8.0and OR = 3.8, 95% CI = 1.3-11.48; respectively).

CONCLUSION

This study highlights critical deficiencies in parental knowledge on the management of tooth avulsion and the need to improve parents' knowledge by developing easily accessible onsite emergency management tools.

Effectiveness of intentional replantation in managing teeth with apical periodontitis: A systematic review

BACKGROUND

Intentional replantation (IR) to treat disease of endodontic origin remains controversial. While IR has been advocated by some clinicians as another valid treatment option, others consider it as a treatment procedure of last resort.

OBJECTIVE

To systematically review and critically evaluate the effectiveness of IR compared with nonsurgical root canal treatment/retreatment or apical surgery in terms of clinical and patient-related outcomes in managing permanent teeth with apical periodontitis (AP).

METHODS

A literature search of five databases (PubMed, Embase, Scopus, Web of Science and Cochrane Central register of Controlled Trials), and the grey literature (Networked Digital Library of Theses and Dissertations, Open Access Theses and Dissertations, DART-Europe E-theses Portal, British Library E-Theses Online Service), from inception to November 2021, was conducted. Randomised clinical trials, comparative clinical trials (CCTs), nonrandomised, retrospective, and prospective comparative cohort and case-control two arm studies which evaluated clinical and/or patient-related outcomes of permanent teeth with AP treated with IR compared with nonsurgical root canal treatment/retreatment or apical surgery were identified. The quality of the studies was appraised using the Cochrane risk of bias tool for randomized trials (RoB 2.0), the Robins-I for nonrandomized controlled clinical trials and the Newcastle-Ottawa scale for observational studies. Two independent reviewers were involved in the literature selection, performed the data extraction and the appraisal of the studies identified; disagreements were resolved in conjunction with a third reviewer.

RESULTS

No comparative study was identified from the literature search. Four longitudinal studies (one prospective and three retrospective) were identified during the screening of titles and abstracts but were excluded after reading the full text, because only IR was evaluated (single arm studies).

DISCUSSION

The available evidence on IR is mainly based on observational studies, which reported high overall mid- to long-term survival, and low complication rates. The results suggest that IR may represent an alternative treatment procedure to solve problems of endodontic origin. However, in the absence of high-quality evidence from CCTs, clinical decision-making should be on a case-by-case basis and in accordance with the clinician's experience and the patient's preference.

CONCLUSION

Clinical studies showed that IR may be a treatment modality to manage problems of endodontic origin. However, clinical trials comparing the effectiveness of IR with nonsurgical root canal treatment/retreatment or apical surgery are still required given the paucity of evidence.

Assessment of Bone Height Changes Based on the Cone-Beam Computed Tomography Following Intentional Replantation for Periodontally Compromised Teeth

Background and Objectives; This study aimed to evaluate the clinical outcomes and bone changes before and after intentional replantation (IR) for periodontally compromised teeth by using cone-beam computed tomography (CBCT). Materials and Methods; Fourteen periodontally involved teeth were selected for IR. A preoperative orthodontic procedure was performed to apply luxation, and the tooth was then gently extracted. Retrograde filling of the root-end canal was performed. Once the tooth was repositioned in the socket, it was splinted with the adjacent tooth. After three months, prosthetic restoration was performed. Results; Clinical parameters and CBCT images were obtained before and after the IR procedure. The height of the alveolar bone was measured on the CBCT images by using software. Most preoperative symptoms, including pain, mobility, probing depth (PD) and bleeding on probing (BOP), significantly decreased after IR (pain: 4.71 to 1.00; mobility: 1.36 to 0.29; PD: 5.60 to 2.85; BOP: 3.50 to 0.79). CBCT analysis indicated an increase in bone height after IR (the amount of change: maxilla, 4.00; mandible, 1.95). Conclusions; A previous study reported that IR for periodontally involved teeth is quite limited. However, in this study, IR of periodontally compromised teeth showed favorable results in clinical and radiographic evaluations, suggesting that IR may be an alternative to extraction of teeth with periodontal disease.

Biomimetic Approaches in Clinical Endodontics

In the last few decades, biomimetic concepts have been widely adopted in various biomedical fields, including clinical dentistry. Endodontics is an important sub-branch of dentistry which deals with the different conditions of pulp to prevent tooth loss. Traditionally, common procedures, namely pulp capping, root canal treatment, apexification, and apexigonesis, have been considered for the treatment of different pulp conditions using selected materials. However, clinically to regenerate dental pulp, tissue engineering has been advocated as a feasible approach. Currently, new trends are emerging in terms of regenerative endodontics which have led to the replacement of diseased and non-vital teeth into the functional and healthy dentine-pulp complex. Root- canal therapy is the standard management option when dental pulp is damaged irreversibly. This treatment modality involves soft-tissue removal and then filling that gap through the obturation technique with a synthetic material. The formation of tubular dentine and pulp-like tissue formation occurs when stem cells are transplanted into the root canal with an appropriate scaffold material. To sum up tissue engineering approach includes three components: (1) scaffold, (2) differentiation, growth, and factors, and (3) the recruitment of stem cells within the pulp or from the periapical region. The aim of this paper is to thoroughly review and discuss various pulp-regenerative approaches and materials used in regenerative endodontics which may highlight the current trends and future research prospects in this particular area.

A new direction in managing avulsed teeth: stem cell-based de novo PDL regeneration

Management of avulsed teeth after replantation often leads to an unfavorable outcome. Damage to the thin and vulnerable periodontal ligament is the key reason for failure. Cell- or stem cell-based regenerative medicine has emerged in the past two decades as a promising clinical treatment modality to improve treatment outcomes. This concept has also been tested for the management of avulsed teeth in animal models. This review focuses on the discussion of limitation of current management protocols for avulsed teeth, cell-based therapy for periodontal ligament (PDL) regeneration in small and large animals, the challenges of de novo regeneration of PDL on denuded root in the edentulous region using a mini-swine model, and establishing a prospective new clinical protocol to manage avulsed teeth based on the current progress of cell-based PDL regeneration studies.

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.

Periodontal ligament repair after active splinting of replanted dogs' teeth

BACKGROUND/AIM

The high rate of root resorption resulting from tooth replantation represents a serious clinical problem. In order to prevent ankylosis and replacement resorption, the contemporary literature highlights the importance of using a flexible stabilization for traumatized teeth. For this purpose, orthodontic devices may be promising for obtaining a better prognosis and periodontal repair. The aim of this study was to evaluate the effect of an active splinting protocol with controlled force in dog's teeth following replantation.

MATERIAL AND METHODS

Sixty premolar roots from three dogs were used. They were submitted to endodontic treatment, hemisected, atraumatically extracted and subsequently replanted. They were divided into four groups: Passive Stabilization (n = 20)-after 20 min in a dry medium; Active Stabilization (n = 20)-after 20 min in a dry medium; Negative control (n = 10)-immediate replantation and passive Stabilization; and Positive control (n = 10)-90 min of extra-alveolar time and passive Stabilization. The samples were collected and submitted to histologic processing. They were then evaluated for the count of inflammatory cells, expression of neurotrophin 4, osteoclasts, apoptotic cells and collagen fibres. The results were submitted to ANOVA or Kruskal-Wallis statistical tests followed by Tukey or Dunn post-tests (α = 5%).

RESULTS

Passive Stabilization with orthodontic brackets without traction used after replantation had the highest number of inflammatory cells (p = .0122), osteoclasts (p = .0013) and percentage of collagen fibres in the periodontal ligament (p < .0001) when compared to Active Stabilization with orthodontic brackets applying amild tensile force. Neurotrophin 4 had no statistically significant difference (p = .05), regardless of the treatment. The apoptotic cells count revealed statistical differences (p < .0001) between Active Stabilization (189.70 ± 47.99) and Positive Control (198.90 ± 88.92) when compared to Passive Stabilization (21.19 ± 32.94).

CONCLUSION

The active splinting protocol using orthodontic appliances generating a light and controlled force favoured periodontal ligament repair of replanted teeth.

Low-intensity pulsed ultrasound attenuates replacement root resorption of avulsed teeth stored in dry condition in dogs

This study aimed to investigate the effects of low-intensity pulsed ultrasound (LIPUS) on replacement root resorption after replantation of avulsed teeth stored in a dry condition in dogs. A total of 73 premolar roots from four male mongrel dogs were intentionally avulsed with forceps and divided into four groups—HN, HL, DN, and DL—according to storage conditions and whether or not they received LIPUS treatment. Thirty-eight roots were kept in Hanks’ Balanced Salt Solution for 30 min (HN and HL groups), whereas the remaining 35 roots were left to dry in the air for an hour (DN and DL groups) prior to replantation. Following replantation, the roots in the HL and DL groups (21 and 18 roots, respectively) received a 20-min daily LIPUS treatment for 2 weeks. The animals were euthanized 4 weeks after the operation. Micro-computed tomography images were acquired for each root and the amount of replacement root resorption was measured three-dimensionally. Histological assessments were also carried out. There was significantly less replacement root resorption for the roots in the DL group compared to the DN group (p < 0.01). Histological findings in the DN group demonstrated evident replacement root resorption, whereas the DL group revealed less severe resorption compared to the DN group. Within the limitations, these results suggest that LIPUS could attenuate the replacement resorption of avulsed teeth stored in a dry condition, thereby improving their prognosis.

Effect of tetracyclines on pulpal and periodontal healing after tooth replantation: a systematic review of human and animal studies

Background

Pulpal and periodontal healing are two main concerns of delayed replantation of avulsed teeth. The objective of this review was to evaluate the effectiveness of topical and systemic application of tetracyclines on pulpal and periodontal healing after tooth replantation.

Methods

A comprehensive electronic search was conducted in six databases. This systematic review was carried out according to Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

After exclusion of 246 irrelevant papers, 14 animal studies and one human study were included in this review. The human study showed that avulsed permanent teeth treated with doxycycline did not show a better clinical outcome for pulp and periodontal healing compared with treatment with normal saline. As for animal studies, significant more pulpal healing was observed in immature teeth treated with topical doxycycline in two researches, while another one study showed that there is no difference between teeth treated with normal saline and teeth treated with doxycycline. Systemic doxycycline exerted no significant effect on pulpal revascularization illustrated by one research. Only one out of four articles illustrated the positive effect of systemic tetracyclines on periodontal healing. One paper reported that intracanal application of demeclocycline promoted favorable periodontal healing. Two articles showed topical doxycycline contributed to favorable periodontal healing, while five studies showed no significant effect of topical tetracyclines on periodontal healing.

Conclusions

As a result of data heterogeneity and limitations of the studies, the effect of topical or systemic application of tetracyclines on pulpal and periodontal healing is inconclusive. More studies are required to get more clinically significant conclusions.

The risks of ankylosis of 89 avulsed human teeth stored in saliva prior to replantation-A re-evaluation of a long-term clinical study

BACKGROUND/AIM

The survival of an avulsed tooth highly depends on the emergency management. The aim of this study was to evaluate the risk of ankylosis for avulsed human teeth stored in saliva preceded by various dry storage conditions prior to replantation.

MATERIAL AND METHODS

Data include 74 patients (54 male and 20 female) with 89 avulsed and replanted teeth (16 immature teeth, 73 mature teeth). Patient ages ranged from 6 to 36 years (median: 13.0 years). All teeth were stored in saliva before replantation. Treatment and follow-up were performed according to a standardized procedure. Follow-up periods ranged from 7 months to 20 years (mean 5.3 years). The risk of ankylosis over time was estimated by the Aalen-Johansen method in relation to the length of dry storage and the stage of root development. The effect of risk factors (root development and length of dry time) on the risk of ankylosis was analysed by Cox regression analysis.

RESULTS

For mature teeth, dry storage for 5 min or less before saliva storage resulted in a 47.4% (95% confidence interval (CI): 32.8-60.7) ankylosis rate. When dry storage was >5 min and <20 min, the risk of ankylosis was 76.8% (95% CI: 45.7-91.5). When dry storage exceeded 20 min prior to saliva storage, ankylosis increased to 89.3% (95% CI: 68.0-96.7). Ankylosis also increased with increasing saliva storage time. Specifically, one additional minute of wet time increased the ankylosis hazard rate (HR) by approximately 1% (CI = [0%, 2%], p = .052). Teeth with mature root development were significantly more frequently affected by ankylosis than teeth with immature root development (HR: 2.4 (95% CI: 1.0-5.5), p = .04).

CONCLUSION

Temporary storage in saliva should be encouraged if an avulsed permanent tooth cannot be immediately replanted or a suitable storage medium such as milk or saline is not immediately available at the place of the accident.

In Vivo Biological Evaluation of Orthodontically Moved Incisors after Replantation

Background and Objectives: There is still considerable controversy regarding the possibility of submitting replanted teeth to orthodontic movement (OM). The purpose of the present study was to evaluate the tissue response after orthodontic movement on replanted teeth. Materials and Methods: Sixty Wistar rats were randomly assigned to four groups (n = 15): G1, replantation without OM after 30 days; G2, replantation with OM after 30 days; G3, replantation without OM after 60 days, and G4, replantation with OM after 60 days. The maxillary left central incisors were extracted and the teeth were stored in milk media. After 30 min, the teeth were replanted and fixed with non-rigid immobilization. All specimens were observed after 30 and 60 days of replantation and then subdivided into two subgroups (with OM or without OM). The animals were euthanized after seven days of the OM started, and the maxillary bone blocks were processed for histological evaluation. Results: The histological results showed periodontal ligament repair in both periods studied without OM; however, ankylosis and root resorption was seen in all orthodontically moved teeth. Conclusions: The orthodontic movement did not favor tissue response in all replanted teeth, regardless of the experimental periods.

The effects of three modified Hank's balanced salt solutions on root resorption of late replanted teeth: A pilot study

PURPOSE

The purpose of this study was to evaluate the effects of replanted rats' teeth that had been soaked in one of three modified Hank's balanced salt solutions (HBSSs) before replantation and after extended extra-oral dry time.

MATERIALS AND METHODS

Maxillary right incisors were extracted from 55 Wistar rats and kept dry for 30 or 60 min (n = 5 each). Afterwards, the pulp was extirpated and both the papilla and enamel organ were removed with a scalpel. Each group of teeth was soaked in one of three modified HBSSs or HBSS alone. After 30 min of immersion in solutions, the root canals were dried and filled with calcium hydroxide paste, and the teeth were replanted. After 8 weeks, animals were euthanized; then, specimens were processed as 5 μm-thick serial sections for histological examination and morphometric assessments.

RESULTS

The percentages of root resorption for the groups were found to be in the following order: HBSS3 (the bFGF group) > the HBSS only group > HBSS2 (the GSH group) > no soaking (the positive control group) > HBSS1 (the ALN group) for 30 min and the positive control group > the HBSS only group > HBSS2 > HBSS3 > HBSS1 for 60 min. The lowest incidence of resorption was observed in immediately replanted teeth (negative control).

CONCLUSIONS

The findings of this study suggest that soaking for 30 min in HBSS containing 1 mM alendronate can significantly inhibit root resorption for avulsed teeth that have been dried for 60 min.

Apical Revascularization after Delayed Tooth Replantation: An Unusual Case

The aim of this paper is to present the clinical and radiological outcome of the treatment involving a delayed tooth replantation after an avulsed immature permanent incisor, with a follow-up of 1 year and 6 months. An 8-year-old boy was referred after dental trauma that occurred on the previous day. The permanent maxillary right central incisor (tooth 11) had been avulsed. The tooth was hand-held during endodontic therapy and an intracanal medication application with calcium hydroxide-based paste was performed. An apical plug with mineral trioxide aggregate (MTA) was introduced into the apical portion of the canal. When the avulsed tooth was replanted with digital pressure, a blood clot had formed within the socket, which moved the MTA apical plug about 2 mm inside of the root canal. These procedures developed apical revascularization, which promoted a successful endodontic outcome, evidenced by apical closure, slight increase in root length, and absence of signs of external root resorption, during a follow-up of 1 year and 6 months.

Effects of near-infrared LED therapy on experimental tooth replantation in rats

BACKGROUND/AIM

Dental avulsion damages periodontal tissues and may induce dentoalveolar ankylosis and root resorption after replantation. The aim of this work was to evaluate the effects of light-emitting diode (LED) therapy after tooth replantation.

MATERIAL AND METHODS

The upper right incisors of 36 male Wistar rats were extracted and replanted after 15 min. The control group (Co, n = 18) was submitted to replantation and the LED group (n = 18) was submitted to replantation and LED therapy (940 nm, 4 J cm^-2 ) for three consecutive days (0, 24, and 48 h). Six animals from each group were euthanized at 7, 14, and 21 days for histological analysis. The upper left incisors were used as a negative control. Data were compared using the Fisher exact test, considering P < 0.05.

RESULTS

After 7 days, the Co (73.3%) and LED (72.2%) groups presented areas of periodontal ligament necrosis. However, periodontal ligament necrosis was more frequent in the LED group at 14 (70%, P < 0.05) and 21 days (43.2%, P < 0.05) in relation to the Co group (33 and 21.6%). Inflammatory cell infiltration was more frequent in the Co group at 7 days (100%) than the LED group (24.4%, P < 0.05), but increased in the LED group after 21 days (83.3%, P < 0.05). Bone necrosis was more frequent in the LED group after 14 (79%, P < 0.05) and 21 days (60%, P < 0.005) than in the Co group (45% and 20%). Bone repair was evident in the Co group at 14 days. All of the replanted teeth had pulp necrosis.

CONCLUSION

The results suggest that the application of LED therapy up to 48 h after tooth replantation may delay periodontal ligament repair.