Effect of zoledronic acid used in the root surface treatment of late replanted teeth: a study in rats

Effect of ELVAX polymer subgingival implants with echistatin on extracted and reimplanted rats' teeth

To investigate the effect of ELVAX polymer subgingival implants incorporated with echistatin peptide on incisor reimplanted tooth in rats. Forty-two male Wistars rats were divided into two groups: echistatin-treated rats (E) and control rats (C). The animals had their right maxillary incisors extracted and treated according to the International Association of Dental Traumatology replantation protocol. The extra-alveolar dry period was 30 and 60 min, and the post-surgical experimental periods were 15, 60, and 90 days. The samples were stained with H&E and analyzed for the presence of an inflammatory response, incidence of resorptions, and dental ankylosis. Results were statistically analyzed (p < 0.05). The presence of inflammatory resorption was significantly higher in group C at 30 and 60 min extra-alveolar time, in the 15-day postoperative period as compared with the E group (p < 0.05). Dental ankylosis was significantly more prevalent in group E in 30 min extra-alveolar time and 15 days postoperative period (p < 0.05). However, in 60 min extra-alveolar time and 60 days postoperative period, dental ankylosis was more prevalent in C group (p < 0.05). The use of ELVAX subgingival implants with echistatin demonstrated therapeutic potential in preventing the experimental resorption process after replantation of maxillary incisors in rats.

The effect of high concentration of zoledronic acid on tooth induced movement and its repercussion on root, periodontal ligament and alveolar bone tissues in rats

Zoledronic acid (ZA) is often prescribed for osteoporosis or resorptive metabolic bone disease. This study aims to evaluate the effect of ZA on orthodontic tooth movement (OTM) and root and bone resorption and its repercussion on root, periodontal ligament and alveolar bone tissues. The experimental group consisted of 72 Wistar rats divided in four subgroups: Naive, Saline and Zoledronic Acid groups at the concentration of 0.2 mg/kg [ZA (0.2)] or 1.0 mg/kg [ZA (1.0)]. The animals were subjected to i.v (dorsal penile vein) administrations of ZA or saline solution, on days 0, 7, 14 and 42. Under anesthesia, NiTi springs were installed in the first left maxillary molar with 50gf allowing the OTM, except for the negative control group (N) for mesial movement of the left first maxillary teeth. The animals were sacrificed and maxillae were removed for macroscopic and histopathological analyzes, scanning electron microscopy, computerized microtomography and confocal microscopy. Treatment with ZA decreased the OTM and the number of osteoclasts and loss of alveolar bone when compared to the naive and saline groups. Reduction of radicular resorption, increased necrotic areas and reduced vascularization in the periodontal ligament were observed in the ZA groups. ZA interferes with OTM and presents anti-resorptive effects on bone and dental tissues associated with a decreased vascularization, without osteonecrosis.

Geomorphologic study of human tooth root surfaces following simulated avulsion by scanning electron microscopy

BACKGROUND/AIMS

Tooth avulsion is the most severe traumatic tooth injury. Immediate replantation after avulsion provides the highest success rate, whereas delayed replantation with dehydration for >1 h always results in ankylosis, replacement resorption, and eventual tooth loss. The aim of this study was to investigate the geomorphologic change of ultrastructure on tooth root surfaces due to dehydration.

MATERIAL AND METHODS

Twenty-four sound human premolars and fully developed third molars without periodontitis were selected for the experiment. Roots were separated into 6-7 pieces with an intact root surface area (3 × 3 mm² ) and then divided into the following groups: fresh group, prolonged dehydration groups (air drying for 1, 2, 4, 12, or 24 h), and dehydrated teeth (air drying for 2 h) treated with acid (Tris-HCl buffer or citric acid buffer). More than six pieces of root from each group were subjected to scanning electron microscopy (SEM) observation. Captured images were exported to ImageJ software to quantitatively analyze the areas covered with fibers. Statistical significance was determined by comparing the means of the different groups using t-testing or one-way analysis of variance followed by post hoc testing.

RESULTS

Fibrous "vegetation" covering the cementum was observed on the fresh root surface by SEM. This was destroyed by dehydration (>1 h), resulting in a root surface resembling the "Gobi Desert." The difference was statistically significant (p < .001). Root surface deteriorated by dehydration could be recovered by the re-use of the fibers embedded in the cementum as acid demineralization of the outer layer of cementum exposed the embedded fibers to simulate the geomorphology of fresh root surface.

CONCLUSIONS

Dehydrated teeth had deteriorated geomorphology of the root surface, which could be reversed by the re-use of the fibers embedded in the cementum using citric acid. Direct evidence from SEM gives new insights into the replantation of dehydrated avulsed teeth.

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.

Effects of Zoledronic Acid on Orthodontic Tooth Movement in Rats

The purpose of this study was to assess the effects of the administration of zoledronic acid (ZA) during orthodontic movement in rats. A hundred and twenty male Wistar rats were applied force of 30 cN with spring closed nickel-titanium to move the upper right first molar to mesial. In the Control Movement group (CM), only tooth movement was performed; the Control Acid Zoledronic group (CAZ) received a single dose (0.1 mg/kg) of ZA; the Experimental Acid Zoledronic group (EAZ) received a single dose (0.1 mg/kg) one week prior to the start of tooth movement; and the Control Without movement group (CWM) that received no drug and without application of tooth movement. The animals were euthanized after 3, 7 and 14 days. Tooth movement was measured using a caliper, the number of osteoclasts using TRAP staining, the expression of mature and immature collagen using picrosirius staining, and the presence of hyaline areas and root resorption using HE. The data were compared using two-way ANOVA, Tukey HSD, Games-Howell and chi-squared test, at the 5% significance level. It was observed a smaller number of osteoclasts and greater percentage of hyaline area in the EAZ group. There was no difference among the groups regarding bone remodeling, root resorption and tooth movement for all observed times.

Effect of bisphosphonates on root resorption after tooth replantation - a systematic review

BACKGROUND/AIM

Replantation of avulsed teeth may lead to root resorption. Bisphosphonates (BPs), a class of drugs of used to treat resorptive diseases of the bone such as osteoporosis and Paget's disease, have been observed to exert an antiresorptive effect on periodontal bone as well. The antiresorptive properties of BPs could prove them useful in preventing root resorption of replanted avulsed teeth. The aim of this systematic review was to analyze and summarize the currently available literature concerning the use of BPs in preventing root resorption of avulsed teeth.

MATERIALS AND METHODS

PubMed/MEDLINE, Google Scholar, ISI Web of Knowledge, and Embase databases were searched using keywords 'bisphosphonate', 'replantation', and 'tooth'. Quality assessment of each study was carried out. In addition, general characteristics and outcomes of each study were summarized.

RESULTS

After exclusion of 116 irrelevant articles, 10 animal studies were included in this review. The majority of the studies suggest that surface application of zoledronate or alendronate reduces root resorption of replanted teeth in animal models. Surface treatment with etidronate had no significant effect on root resorption, and intracanal etidronate accelerated resorption.

CONCLUSION

Surface application of zoledronate and alendronate reduces root resorption of replanted teeth in animal models. However, the efficacy of intracanal usage of BPs is still debatable.

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

Introduction:

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

Methods and Materials:

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

Results:

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

Conclusion:

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

Could zoledronic acid prevent root resorption in replanted rat molar?

BACKGROUND/AIM

In this study, we evaluated whether zoledronate could suppress the progression of external root resorption in rat due to delayed replantation by inhibiting osteoclastic activity. Also, we estimated the optimal dosage of zoledronate in root treatment of the rat model for a maximum effect of zoledronate.

MATERIAL AND METHODS

Maxillary first molars in Sprague Dawley rats (N = 84) were extracted, dried for 60 min, and then replanted. The rats were divided into 6 groups (1 mM alendronate, and 1, 5, 10, 20, 40 μM zoledronate). At 4 and 8 weeks postreplantation, the animals were sacrificed and evaluated by radiographic and histological analysis.

RESULTS AND CONCLUSION

There were no significant differences at 4 weeks. However, at 8 weeks, 10, 20, and 40 μM ZOL showed more increased radiopaque and smaller periapical lesion in radiographic analysis. In histological analysis, all groups showed similar inflammatory root resorption rate at 4 weeks. However, at 8 weeks, 20 and 40 μM ZOL showed lower rate than those of other groups (P < 0.05). In concerning of replacement resorption, there were no significant differences statistically. In this animal experiment, zoledronate was capable of limiting the occurrence of root resorption in delayed replantation model. In particular, 20 μM dosage of zoledronate solution showed the most effective dose in long-term follow up and might be suitable for inhibition of root resorption in delayed tooth replantation.

What is the Best Root Surface Treatment for Avulsed Teeth?

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

Soy milk as a storage medium to preserve human fibroblast cell viability: an in vitro study

Soy milk (SM) is widely consumed worldwide as a substitute for cow milk. It is a source of vitamins, carbohydrates and sugars, but its capacity to preserve cell viability has not been evaluated. The purpose of the present study was to investigate the efficacy of SM to maintain the viability of human fibroblasts at short periods compared with different cow milks. Human mouth fibroblasts were cultured and stored in the following media at room temperature: 10% Dulbecco's Modified Eagle Medium (DMEM) (positive control group); long shelf-life ultra-high temperature whole cow milk (WM); long shelf-life ultra-high temperature skim cow milk (SKM); powdered cow milk (PM); and soy milk (SM). After 5, 15, 30 and 45 min, cell viability was analyzed using the MTT assay. Data were analyzed statistically by the Kruskal-Wallis test with post-analysis using the Dunn's method (α=0.05). SKM showed the lowest capacity to maintain cell viability in all analyzed times (p<0.05). At 30 and 45 min, the absorbance levels in control group (DMEM) and SM were significantly higher than in SKM (p<0.05). Cell viability decreased along the time (5-45 min). The results indicate that SM can be used as a more adequate storage medium for avulsed teeth. SKM was not as effective in preserving cell viability as the cell culture medium and SM.