Evaluation of the anti-resorptive ability of an experimental acetazolamide paste for the treatment of late replanted teeth: a study in rats

Clinical study of laminar resorption: Part 2- outcomes, review and proposal for classification

PURPOSE

To analyze and review the clinical features and main outcomes of laminar resorption from the UK osteo-odonto-keratoprosthesis (OOKP) cohort.

METHODS

A retrospective review of case records was undertaken for patients who underwent keratoprostheses between 1996 and 2014 at the Sussex Eye Hospital, Brighton, UK. The main clinical outcomes of resorption, including its clinical signs, complications, treatments, and laminar survival, were evaluated.

RESULTS

Sixty-four patients (25-females, 39-males) were included, and in total, 74 laminae (3-tibial, 11-allografts, 60-autografts) were implanted. The age of the patients ranged from 20 to 91 years. Focal laminar thinning was the first sign of detectable resorption in 50% of autografts and 27% of allografts. All the tibial grafts and 55% of allografts presented with complications of resorption like endophthalmitis and aqueous leakage as the first signs of resorption. The survival of first implanted autografts was 82.4%(±6.3%) at 18 years, which was enhanced to 91.5%(±5.0%) by prophylactic exchanges of critically resorbed laminae with new laminae. Visual acuity survival analysis did not reveal a statistically significant difference between grafts with and without resorption for all graft types (p = 0.825). Patients treated with Alendronic acid and acetazolamide demonstrated trends toward the slower progression of resorption, but this was not statistically significant.

CONCLUSIONS

Focal laminar thinning was the common presenting feature of resorption in autografts. Timely replacement of the resorbed laminae with new laminae should be considered to avoid complications. Alendronic acid supplementation may be considered in high-risk cases of resorption to reduce further progression.

Endodontic approach in a replanted tooth with an immature root apex and chronic apical periodontitis: a case report

This study describes the clinical steps taken in the treatment of a patient who had an avulsed right upper central incisor that presented with incomplete root development and chronic apical periodontitis. A 7-year-old boy was referred from a private dentist to a dental office specializing in endodontics. The tooth had remained in a dry environment for 20 minutes, and tooth replantation was performed at an emergency appointment. After clinical and radiographic examinations, root canal decontamination was performed, followed by several changes in intracanal calcium hydroxide medication. Blood clot formation was attempted, but bleeding within the root canal was insufficient; therefore, we opted for an intracanal medication change to stimulate mineralized tissue formation in the apical region. Root obturation was performed 45 days after the last change of intracanal medication, and clinical, radiographic, and tomographic follow-up examinations were performed at 3, 6, 18, and 40 months after the endodontic intervention. The increase in thickness and length of the root structure and the absence of root resorption were verified through follow-up examinations. Therefore, it was concluded that the procedures used were successful for tooth replantation.

Effect of root surface treatment with denusomab after delayed tooth replantation

OBJECTIVES

To evaluate denosumab, a human monoclonal antibody that mimics the effects of osteoprotegerin in bone metabolism, as a topical treatment of root surface to be used prior to delayed tooth replantation.

MATERIALS AND METHODS

Thirty-six rats' right incisors were used. Teeth were extracted and divided into: delayed replantation without root surface treatment (control); delayed replantation with root surface treatment with denosumab 60 mg/mL and 30 mg/mL, respectively, for 10 min both experimentals groups. After that, the root canals were filled with calcium hydroxide and replanted. After 15 and 60 days, the animals were euthanized, and the samples were collected and processed for microscopic analysis. Histological sections were performed, and stained with HE to describe the dental characteristics, measure ankylosis, replacement resorption, and dental resorption by conventional microscopy. Also, was performed Brown & Brenn staining and immunohistochemistry for RANKL, OPG, and periostin.

RESULTS

Denosumab 60 mg/mL reducted ankylosis (p < 0.0001), replacement resorption (p < 0.0001), and tooth resorption, 60 days after replantation, compared to untreated replanted teeth (p < 0.005). Lower bacterial contamination in root surface in the denosumab treatment groups was found, regardless of the concentration used (p < 0.001). Also, denosumab treatment inhibited the expression of RANKL without modulating OPG. Periostin was observed in periodontal ligament of replanted tooth, although this labelling was absent in the ankylosis areas, in both experimental periods.

CONCLUSION

Treatment of the root surface with denosumab at 60 mg/mL of rat teeth before delayed replantation reduced dental root resorption compared with the untreated teeth after 60 days.

CLINICAL RELEVANCE

Survival of a replanted tooth has been a challenge in clinical practice. The use of a medication, such as denosumab, to limit dental root resorption represents an important therapeutical approach.

Influence of anti-allergic drugs used systemically on the process of root resorption during delayed tooth replantation: A study in rats

BACKGROUND/AIM

Anti-allergic drugs can inhibit the hard tissue resorption process, and due to similarities between root resorption and bone mechanisms, it can be inferred that these drugs may also control root resorption. The aim of this study was to analyze the effects of anti-allergic drugs used systemically on the process of root resorption following delayed tooth replantation.

MATERIALS AND METHODS

Thirty-two maxillary right incisors of rats were extracted and subsequently replanted. Rats were divided into four groups according to the anti-allergic drug administered: the rats in groups DEX, Q, and MO were treated systemically with dexamethasone phosphate, quercetin, and montelukast, respectively, and no systemic medication was administered to rats in group C. After 60 days, the animals were euthanized, and the specimens were processed for histomorphometric and immunohistochemical analyses. Statistical significance was set at P < .05.

RESULTS

There were no significant differences between the groups in terms of inflammatory resorption, replacement resorption, or presence of tartrate-resistant acid phosphatase. In terms of events occurring in the periodontal ligament space, there was a difference between groups Q and MO due to the presence of dental ankylosis and inflammatory connective tissue (P < .05). A difference in inflammatory cells was also observed through CD45 immunolabeling between the DEX and Q groups when compared to the C group (P < .05).

CONCLUSION

The systemic administration of anti-allergic drugs did not have an effect on the process of root resorption following delayed tooth replantation.

Anti-inflammatory and anti-resorptive efficacy of adrenergic blockers on late replanted rat incisors

BACKGROUND/AIM

In addition to their anti-inflammatory and anti-osteoclastogenesis properties, adrenergic blockers may also have promising anti-resorptive effects that can prevent root resorption when teeth are replanted because of avulsion. The aim of this study was to investigate the effects of phentolamine (Ph) and propranolol (Pr) in gels on the repair process of late replanted rat incisors. A further aim was to evaluate the biocompatibility of both drugs to human periodontal ligament fibroblasts (HPDLFs).

MATERIALS AND METHODS

Forty-eight maxillary right incisors were extracted from male Wistar rats, stored in paper napkins for 60 minutes, and randomly allocated to one of eight groups (n = 6). The root canal, root surface, and alveolus were treated with 0.75 µg/mL Ph gel (Ph0.75), 10 µg/mL Ph gel (Ph10), 100 µg/mL Ph gel (Ph100), 2.5 µg/mL Pr gel (Pr2.5), 10 µg/mL Pr gel (Pr10), 100 µg/mL Pr gel (Pr100), or sodium carboxymethylcellulose gel (CMC) before replantation. In the control group (CH), only the root canal was treated with calcium hydroxide paste. Thirty days following surgery, the animals were euthanized, and the right hemimaxilla was removed to perform micro-CT and histomorphometric analysis to determine osteoclastic activity. Ethanolic solutions of Ph10 and Pr10 were selected based on the in vivo study, and the viability of HPDLFs stimulated with lipopolysaccharide was determined by MTT assays.

RESULTS

The micro-CT and histomorphometric analysis revealed no significant differences among the treatments (P > .05). The presence of active osteoclasts was significantly decreased in the Ph10 and Pr10 groups (P < .05). Ph10 and Pr10 produced statistically similar cell survival rates compared to the control group (P > .05).

CONCLUSIONS

Ph10 and Pr10 significantly decreased osteoclastogenesis in delayed replanted rat teeth and were not cytotoxic toward HPDLFs.

Effect of calcium hydroxide on inflammatory root resorption and ankylosis in replanted teeth compared with other intracanal materials: a review

Calcium hydroxide (CH) is the gold-standard intracanal dressing for teeth subjected to traumatic avulsion. A common complication after the replantation of avulsed teeth is root resorption (RR). The current review was conducted to compare the effect of CH with that of other intracanal medications and filling materials on inflammatory RR and replacement RR (ankylosis) in replanted teeth. The PubMed and Scopus databases were searched through June 2018 using specific keywords related to the title of the present article. The materials that were compared to CH were in 2 categories: 1) mineral trioxide aggregate (MTA) and endodontic sealers as permanent filling materials for single-visit treatment, and 2) Ledermix, bisphosphonates, acetazolamide, indomethacin, gallium nitrate, and enamel matrix-derived protein (Emdogain) as intracanal medicaments for multiple-visit management of avulsed teeth prior to the final obturation. MTA can be used as a single-visit root filling material; however, there are limited data on its efficacy due to a lack of clinical trials. Ledermix and acetazolamide were comparable to CH in reducing RR. Emdogain seems to be an interesting material, but the data supporting its use as an intracanal medication remain very limited. The conclusions drawn in this study were limited by the insufficiency of clinical trials.

Efeitos do laser de diodo de alta potência e da fotobiomodulação em dentes de ratos reimplantados tardiamente

Resumo Introdução A busca por protocolos efetivos para reduzir a incidência de reabsorções radiculares e favorecer a reparação do ligamento periodontal perdido ainda representa um grande desafio, tendo em vista o prognóstico desfavorável dos reimplantes dentais tardios. Objetivo Avaliar, por meio da análise histológica, os efeitos do laser de alta potência e da fotobiomodulação na ocorrência de reabsorção radicular e no reparo periodontal, em dentes reimplantados tardiamente. Material e método Foram utilizados 50 incisivos centrais direitos de ratos Wistar. Após a extração, os espécimes foram divididos em cinco grupos (n = 10): G1 (controle positivo): reimplante imediato; G2 (controle negativo): reimplante tardio (RT): espécimes mantidos em ambiente seco por 60 minutos, sem tratamento adicional; G3: RT associado ao tratamento da superfície radicular com laser diodo de alta potência (810 nm, 1.5 W); G4: RT + superfícies radiculares e feridas alveolares tratadas com fotobiomodulação (laser diodo 660 nm, 30 mW e 780 nm, 40 mW, respectivamente); G5: RT + superfícies radiculares irradiadas com laser de alta e alvéolos com fotobiomodulação, nos mesmos parâmetros que G3 e G4, respectivamente. Após 60 dias, os animais foram eutanasiados. Os espécimes foram processados para análise histológica. Resultado G3 e G5 apresentaram as menores médias de scores com relação à ocorrência de reabsorções radiculares e anquilose, quando comparados a G2 e G4 (Teste Kruskall-Wallis, p<0,05). Com relação ao reparo periodontal, todos os grupos experimentais (G3, G4 e G5) apresentaram médias de escores inferiores (Teste Kruskall-Wallis, p<0,05) comparadas ao G1 e semelhantes ao G2 (Teste Kruskall-Wallis, p>0,05). Conclusão O laser de alta potência, associado ou não à fotobiomodulação, diminuiu a ocorrência das reabsorções radiculares e da anquilose, e a fotobiomodulação não favoreceu o controle das reabsorções radiculares nem o reparo periodontal.

Effect of ethylenediaminetetraacetic acid and hyaluronic acid on the viability and cytokine expression of periodontal ligament fibroblasts

BACKGROUND/AIMS

Dental root cell proliferation following tooth avulsion has not been well researched. Understanding the effects of dry time and dentin treatment influences on cell proliferation is essential to provide evidence-based guidelines for tooth replantation. The study evaluated the viability of periodontal ligament fibroblasts (PLF) in contact with roots, submitted to surface treatments with ethylenediaminetetraacetic acid (EDTA) and hyaluronic acid (HA) at different times, including to quantify inflammatory cytokines interleukin (IL)-6, IL-8, IL-1β and TNF-α expressed by PLF. The adhesion of fibroblasts to treated root surfaces was also evaluated.

MATERIAL AND METHODS

One hundred and eight cementum discs from bovine teeth were randomly divided into groups according to time periods of being dry (n = 12) as follows: (i) fresh discs that were not kept dry, (WD); (ii) dry for 1 hour (1 hd); and (iii) dry for 24 hours (24 hd). The discs were subdivided into 3 subgroups (n = 12) according to surface treatments: (iv) no treatment, (v) treatment with EDTA, (vi) treatment with HA. The discs were placed in 96-well plates, and PLF were seeded and kept in contact with the discs for 48 hours. Cell viability on the surface of the discs was assessed by XTT, and PLF adhesion was evaluated using scanning electron microscopy (SEM). Quantification of cytokines was performed using enzyme-linked immunosorbent assay (ELISA). Data were submitted to ANOVA and Tukey's test (α = .05).

RESULTS

Surface treatment had a statistically significant effect on the cell viability in groups WD (P = .03), 1 hd (P = .01) and 24 hd (P = .048). PLF in contact with dried root surfaces expressed more cytokines without treatment with IL-6 decreasing the expression when treated with HA for 24 hours. SEM also showed adhesion of PLF to the surface of all discs at all time periods.

CONCLUSION

EDTA + HA is an alternative treatment for cases of avulsed teeth as it promoted adhesion and increased viability of PLF.

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.

Evaluation of intracanal acetazolamide in late reimplanted rat teeth

Objective:

The aim of this study was to evaluate the use of acetazolamide combined with different agents as intracanal medication in late reimplanted rat teeth.

Materials and Methods:

In 100 Wistar rats, divided into 5 groups of 20, one of the following medications was used: Acetazolamide liquid (AL); AL with calcium hydroxide powder (ALHC); acetazolamide powder with AL; acetazolamide powder with physiological solution; and calcium hydroxide with physiological solution (control). At 30 and 60 days after reimplantation, the animals were sacrificed, tissues were processed, and cuts were stained with hematoxylin and eosin. An optical microscope was used to determine the following: percentage of inflammatory root resorption (RRI); percentage of substitute root resorption (RRS); and presence of ankylosis. The data obtained was submitted for statistical analysis.

Results:

Group ALHC had a significantly higher RRS than the control group at 60 days (P = 0.01). Group AL showed significantly less ankylosis than the other groups, including the control, at 30 days. AL showed results similar to those of the control group with respect to RRS.

Conclusion:

Acetazolamide has the potential to be an effective intracanal medication.