Effect of root surface treatment with propolis and fluoride in delayed tooth replantation in rats

Abstract – Replantation is an acceptable option for treatment of an avulsed permanent tooth. Nevertheless, an extended extraoral period damages the periodontal ligament and results in external root resorption. The purpose of this study was to assess by histologic and histometric analysis, the influence of propolis 15% (natural resinous substance collected by Apis mellifera bees from various plants) and the fluoride solution used as root surface treatment on the healing process after delayed tooth replantation. Thirty Wistar (Rattus norvegicus albinus) rats were submitted to extraction of their upper right incisor. The teeth were maintained in a dry environment for 60 min. After this, the pulp was extirpated and the papilla, enamel organ and periodontal ligament were removed with scalpel. The teeth were divided into three experimental groups: Group I – teeth immersed in 20 ml of physiologic saline; Group II – teeth immersed in 20 ml of 2% acidulated phosphate sodium fluoride; Group III – teeth immersed in 20 ml of 15% propolis. After 10 min of immersion in the solutions, the root canals were dried and filled with calcium hydroxide paste and the teeth were replanted. The animals were euthanized 60 days after replantation. The results showed that similar external root resorption was seen in the propolis and fluoride groups. Teeth treated with physiologic saline tended to have more inflammatory root resorption compared with those treated with fluoride or propolis. However, the comparative analysis did not reveal statistically significant differences (P > 0.05) between the treatment modalities when used for delayed tooth replantation.     

Effect of low‐level laser therapy on the healing process after tooth replantation: a histomorphometrical and immunohistochemical analysis

Abstract – Success of tooth replantation is limited because part of the replanted tooth is lost because of progressive root resorption. This study used histomorphometry and immunohistochemistry to evaluate the effect of low‐level laser therapy (LLLT) on the healing process of rat teeth replanted after different extra‐oral periods, simulating immediate and delayed replantation. Sixty Wistar rats (Rattus norvegicus albinus) had their maxillary right incisors extracted and randomly assigned to six groups (n = 10): C4, C30 and C45, in which the teeth were replanted 4 min (immediate), 30 min (delayed) and 45 min (delayed) after extraction, respectively, and L4, L30 and L45, in which the teeth were replanted after the same extra‐alveolar times, but the root surfaces and the alveolar wounds were irradiated with a gallium–aluminum–arsenate (GaAlAs) diode laser before replantation. The animals were sacrificed after 60 days. The anatomic pieces containing the replanted teeth were obtained and processed for either histomorphometrical analysis under optical microscopy or immunohistochemical expression of receptor activator of nuclear factor Kappa‐B (RANK), and its ligand (RANKL), osteoprotegerin (OPG) and tartrate‐resistant acid phosphatase (TRAP) proteins. Areas of external replacement and inflammatory root resorption were observed in all groups, without statistically significant differences (P > 0.05). Ankylosis was more frequent in L30 than in C30 (P < 0.05). RANKL immunostaining predominated over RANK and OPG immunostaining in both groups with immediate tooth replantation (P < 0.05). For the 45‐min extra‐alveolar time, however, there was greater evidence of RANK immunostaining compared to RANKL for both control and laser‐treated groups (P < 0.05). Positive TRAP immunostaining predominated in L4 and L30 (P < 0.05). In conclusion, under the tested conditions, the treatment of the root surface and the alveolar wound with LLLT did not improve the healing process after immediate and delayed tooth replantation in rats.     

In Vitro Evaluation of Dentin Hydraulic Conductance After 980 nm Diode Laser Irradiation

Background: Dentin hypersensitivity treatments are based on the physical obliteration of the dentinal tubules to reduce hydraulic conductance. The aim of the present study is to evaluate the hydraulic conductance of bovine root dentin after irradiation with a 980‐nm diode laser, with or without associated fluoride varnish. Methods: Sixty bovine root dentin specimens were divided into six groups (n = 10 in each group): G1, G3, and G5 (0.5 W, 0.7 W, and 1 W diode laser, respectively); G2, G4, and G6 (fluoride varnish application + 0.5 W, 0.7 W, and 1 W diode laser, respectively). The dentin hydraulic conductance was evaluated at four time periods with a fluxmeter: 1) with smear layer, 2) after 37% phosphoric acid etching, 3) after the treatments, and 4) after 6% citric acid challenge. After the dentinal fluid flow measurements, specimens were also evaluated for mineral composition using energy dispersive X‐ray spectroscopy (EDS). Results: Analysis demonstrated a better result with increased irradiation power (P <0.001), especially if the diode laser irradiation was associated with the application of fluoride varnish (P <0.001), ensuring a greater reduction in permeability. Considering the groups treated only with laser irradiation, the 1 W group was superior when compared with the 0.5 W and 0.7 W irradiated groups immediately after treatment (P <0.001). After citric acid testing, all groups showed similar results, except when comparing the 1 W groups with the 0.5 W groups (P = 0.04). EDS results of the irradiated groups showed an increase in the proportion of calcium and phosphorus ions, which demonstrates a superficial composition modification after laser treatments. Conclusion: Laser irradiation of exposed dentin promoted significant reduction in the dentin hydraulic conductance, mainly with higher energy densities and association with fluoride varnish.     

The effects of topical application of bisphosphonates on replanted rat molars

Abstract – The purpose of this study was to evaluate the potential usefulness of two bisphosphonates (BPs) (etidronate and zoledronate), compared with that of alendronate, which is a well‐known drug for delayed replantation, in decreasing or preventing inflammatory root resorption and replacement root resorption in replanted teeth. Eighty‐four Sprague Dawley rat maxillary first molars were extracted, dried for 60 min and then replanted after root treatment. The rats were divided into four groups (control, alendronate, etidronate, zoledronate) as following treatments of avulsed root before replantation. At 7, 14, and 28 days postreplantation, the animals were sacrificed and the samples obtained and process for microscopic analysis. The data were statistically analyzed with the SPSS procedure, anova test and each test was complemented by the Tukey’s post hoc test. The result indicated that topical application of alendronate and zoledronate, both nitrogen containing BPs, prevented inflammatory root resorption and inflammatory cell response in the delayed replantation model. Both drugs were demonstrated similar effects in the delayed tooth replantation model (P = 0.9). Etidronate did not prevent inflammatory root resorption and inflammation in the delayed replantation (P < 0.05). No significant differences in replacement root resorption were observed among all drugs. These results suggest that when teeth are dried and not replanted immediately, zoledronate, like alendronate, may prevent root resorption and facilitates the regeneration of periodontal tissues after replantation.     

Short-term vs long-term calcium hydroxide therapy after immediate tooth replantation: a histomorphometric study in monkey's teeth

Abstract – Endodontic treatment is an important step of tooth replantation protocols, but the ideal moment for definitive obturation of replanted teeth has not yet been established. In this study, a histomorphometric analysis was undertaken to evaluate the repair process on immediate replantation of monkey’s teeth after calcium hydroxide (CH) therapy for 1 and 6 months followed by root canal filling with a CH‐based sealer (Sealapex^®). The maxillary and mandibular lateral incisors of five female Cebus apella monkeys were extracted, kept in sterile saline for 15 min, replanted and splinted with stainless steel orthodontic wire and composite resin for 10 days. In Group I (control), definitive root canal filling was performed before tooth extraction. In Groups II and III, CH therapy started after removal of splint, and definitive root canal filling was performed 1 and 6 months later, respectively. The animals were euthanized 9 months after replantation, and specimens were processed for histomorphometric analysis. In all groups, epithelial attachment occurred at the cementoenamel junction or very close to this region; the areas of resorption on root surface had small extension and depth and were repaired by newly formed cementum; and the periodontal ligament was organized. Statistical analysis of the scores obtained for the histomorphometric parameters did not show any statistically significant difference (P = 0.1221) among the groups. The results suggests that when endodontic treatment is initiated 10 days after immediate replantation and an antibiotic regimen is associated, definitive root canal filling can be performed after a short‐term CH therapy.     

Analysis of the healing process in delayed tooth replantation after root canal filling with calcium hydroxide,Sealapex and Endofill: a microscopic study in rats

Abstract – The major concern in the therapeutics of tooth replantation refers to the occurrence of root resorption and different approaches have been proposed to prevent or treat these complications. The purpose of this study was to evaluate tissue response to delayed replantation of anterior rat teeth treated endodontically using calcium hydroxide, Sealapex, and Endofill without the placement of gutta‐percha cones. Thirty rats had their right upper incisor extracted and maintained in dry storage for 60 min. After removal of the dental papilla, enamel organ, pulp tissue, and periodontal ligament remnants, the teeth were immersed in 2% sodium fluoride phosphate acidulated, pH 5.5, for 10 min. The root canals were dried with absorbent paper points and the teeth were assigned to three groups (n = 10) according to the filling material. Group I – calcium hydroxide and propyleneglycol paste, Group II – Sealapex, and Group III – Endofill. The sockets were irrigated with saline and the teeth were replanted. Replacement resorption, inflammatory resorption and ankylosis were observed in all groups. Although the occurrence of inflammatory resorption was less frequent in Group I, there were no statistically significant differences among the groups. It may be concluded that compared to the paste, filling the root canals with Sealapex and Endofill sealers without the placement of gutta‐percha cones did not provide better results.     

DELAYED TOOTH REPLANTATION AFTER ROOT SURFACE TREATMENT WITH SODIUM HYPOCHLORITE AND SODIUM FLUORIDE: HISTOMORPHOMETRIC ANALYSIS IN RATS

In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin-embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn''s tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other.     

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

Abstract – When late replantation is performed, the root surface and root canal should be treated. Notwithstanding failures still occur, because of the high rates of root resorption, evidencing the need to search for substances that may inhibit root resorption. The acetazolamide is a known anti‐resorptive agent, and its use as root canal dressing may increase the success rates in the treatment of root resorption. Therefore, this study evaluated the effect of an acetazolamide paste used as root canal dressing in late replanted teeth. The study was conducted on 24 maxillary right incisors of rats, which were avulsed and divided in two groups. In group I, the teeth were kept dry for 30 min, had their root surfaces rubbed with a blade, and were treated with 2% sodium fluoride at pH 5.5 for 20 min; the root canals were instrumented and filled with acetazolamide paste; and then the teeth were replanted. In group II, the treatment was similar to group I, except for the root canal dressing, with utilization of calcium hydroxide in group II. At 15 and 60 days after replantation, the animals were killed and the specimens were processed in a histotechnical laboratory for microscopic and morphometric analysis. The results demonstrated the ability of both intracanal substances to limit root resorption, yet they were unable to completely inhibit the root resorption. Replacement resorption lacunae were present in greater proportion in group II, at 60 days. It was concluded that the acetazolamide paste was effective to limit the root resorption, being more effective in limiting the replacement resorption compared with calcium hydroxide.     

Effect of the treatment of root surface-adhered necrotic periodontal ligament with propolis or fluoride in delayed rat tooth replantation

Objectives

The purpose of this study was to evaluate the application of 15 % propolis and 2 % acidulated-phosphate sodium fluoride solutions on the root surface-adhered necrotic cemental periodontal ligament in delayed tooth replantation.

Materials and methods

Thirty Wistar rats (Rattus norvegicus, albinus) had their right upper incisor extracted and maintained in dry storage for 60 min. After this period, the dental papilla, enamel organ, and pulp tissue were removed, and the animals were randomly assigned to three groups: group I = immersion in saline for 10 min; group II = immersion in a 2 % acidulated-phosphate sodium fluoride solution for 10 min; and group III = immersion in a 15 % propolis and propylene glycol solution for 10 min. The root canals were filled with a calcium hydroxide paste and the teeth were replanted.

Results

Inflammatory resorption, replacement resorption, and ankylosis were observed in all groups without a statistically significant difference (p?>?0.05) among them.

Conclusions

Under the tested conditions, the application of fluoride or propolis on root surface-adhered necrotic periodontal ligament did not favor the healing process in delayed tooth replantation.     

Influence of enamel matrix derivative (Emdogain®) and sodium fluoride on the healing process in delayed tooth replantation: histologic and histometric analysis in rats

Abstract – Although it has already been shown that enamel matrix derivative (Emdogain^®) promotes periodontal regeneration in the treatment of intrabony periodontal defects, there is little information concerning its regenerative capacity in cases of delayed tooth replantation. To evaluate the alterations in the periodontal healing of replanted teeth after use of Emdogain^®, the central incisors of 24 Wistar rats (Rattus norvegicus albinus) were extracted and left on the bench for 6 h. Thereafter, the dental papilla and the enamel organ of each tooth were sectioned for pulp removal by a retrograde way and the canal was irrigated with 1% sodium hypochlorite. The teeth were assigned to two groups:in group I, root surface was treated with 1% sodium hypochlorite for 10 min (changing the solution every 5 min), rinsed with saline for 10 min and immersed in 2% acidulated‐phosphate sodium fluoride for 10 min; in group II, root surfaces were treated in the same way as described above, except for the application of Emdogain^® instead of sodium fluoride. The teeth were filled with calcium hydroxide (in group II right before Emdogain^® was applied) and replanted. All animals received antibiotic therapy. The rats were killed by anesthetic overdose 10 and 60 days after replantation. The pieces containing the replanted teeth were removed, fixated, decalcified and paraffin‐embedded. Semi‐serial 6‐μm‐thick sections were obtained and stained with hematoxylin and eosin for histologic and histometric analyses. The use of 2% acidulated‐phosphate sodium fluoride provided more areas of replacement resorption. The use of Emdogain^® resulted in more areas of ankylosis and was therefore not able to avoid dentoalveolar ankylosis. It may be concluded that neither 2% acidulated‐phosphate sodium fluoride nor Emdogain^® were able to prevent root resorption in delayed tooth replantation in rats.     

Intracanal bisphosphonate does not inhibit replacement resorption associated with delayed replantation of monkey incisors

Abstract – Progressive replacement resorption following delayed replantation of avulsed teeth has proved to be an intractable clinical problem. A wide variety of therapeutic approaches have failed to result in the predictable arrest of resorption, with a good long‐term prognosis for tooth survival. Bisphosphonates are used in the medical management of a range of bone disorders and topically applied bisphosphonate has been reported to inhibit root resorption in dogs. This study evaluated the effectiveness of a bisphosphonate (etidronate disodium) as an intracanal medicament in the root canals of avulsed monkey teeth, placed before replantation after 1 h of extraoral dry storage. Incisors of six Macaca fascicularis monkeys were extracted and stored dry for 1 h. Teeth were then replanted after canal contamination with dental plaque (negative control) or after root canal debridement and placement of etidronate sealed in the canal space. A positive control of calcium hydroxide placed 8–9 days after replantation was also included. All monkeys were sacrificed 8 weeks later and block sections were prepared for histomorphometric assessment of root resorption and periodontal ligament status. Untreated teeth showed the greatest extent of root resorption (46% of the root surface), which was predominantly inflammatory in nature. Calcium hydroxide treated teeth showed the lowest overall level of resorption (<30% of the root surface), while the bisphosphonate‐treated group was intermediate (39%). Ankylosis, defined as the extent of the root surface demonstrating direct bony union to both intact and resorbed root surface, was the lowest in the untreated control group (15% of the root surface), intermediate in the calcium hydroxide group (27%) and the highest in the bisphosphonate group (41%). Bony attachment to the tooth root was divided approximately equally between attachment to intact cementum and to previously resorbed dentin. Overall, bisphosphonate resulted in a worse outcome than calcium hydroxide in terms of both root resorption and ankylosis.     

Histological and immunohistochemical analyses of the chronology of healing process after immediate tooth replantation in incisor rat teeth

Abstract – Dental tissues have special characteristics, and its regenerative capacity is noteworthy. However, understanding the circumstances that lead to regeneration is challenging. In this study, the chronology of the healing process after immediate replantation of rat incisor teeth was examined by histological and immunohistochemical analyses within a 60‐day period. Thirty‐six male Wistar rats had their maxillary right incisors extracted and replanted after 15 min in saline storage. The rats were sacrificed immediately 3, 7, 15, 28, and 60 days after replantation. The histological analysis showed rupture of the periodontal ligament and formation of a blood clot, which started being replaced by a connective tissue after 3 days. At 7 days, the gingival mucosa epithelium was reinserted and areas of root resorption could be seen. At 15 days, the periodontal ligament was repaired. At 3 days, the pulp presented an absence of the odontoblast layer, which started being replaced by a connective tissue. This tissue suffered gradual calcification, filling the root canal at 28 and 60 days. The root ends were closed. The immunohistochemical analysis revealed greater expression of OP, OPG, and RANK proteins in the initial periods (0 and 3 days), while TRAP expression predominated at 28 and 60 days (P < 0.05). In conclusion, in delayed tooth replantation, there is great new bone formation activity in the earlier periods of the repair process, while a predominance of bone resorption and remodeling is observed in the more advanced periods.     

Use of vitamin C in delayed tooth replantation

This study evaluated microscopically the effects of root surface treatment with three different solutions in delayed rat teeth replantation. Central incisors from 30 rats (Rattus norvegicus, albinus Wistar) were extracted and left on a bench for 6 h. The pulps were extirpated and root canals were irrigated with 1% sodium hypochlorite. After endodontic treatment, the root surfaces of all teeth were submitted to a 10-min treatment with 1% sodium hypochlorite, changed every 5 min. The teeth were then rinsed with saline for 10 min and assigned to 3 groups with ten specimens each. Groups I, II and III were treated, respectively, with 2% acidulated-phosphate sodium fluoride, vitamin C solution and effervescent vitamin C (2 g, Redoxon. After root surface treatment, the teeth were filled with calcium hydroxide and replanted. The animals were sacrificed after 10 and 60 days. Group I (fluoride) presented the largest areas of replacement resorption and ankylosis. Comparing both vitamin C groups, Group III (effervescent vitamin C) yielded better results, showing more areas of ankylosis and replacement resorption than areas of inflammatory resorption.     

Incidence of Root Resorption after the Replantation of Avulsed Teeth: A Meta-analysis

Introduction

An avulsion injury is a serious trauma to pulp and periodontal tissues. After avulsion and replantation, teeth are at risk of infection and root resorption, which may affect treatment outcome and survival rate. Thus, the purpose of this systematic review was to evaluate the incidence of root resorption after the replantation of avulsed teeth.

Microscopic investigation of the use of gallium nitrate for root surface treatment in rat teeth submitted to delayed replantation

The aim of this study was to investigate the effect of gallium nitrate solution, an anti-resorption substance, when applied for root surface treatment in rat teeth submitted to delayed replantation, in order to inhibit the root resorption process and enhance repair. For such purpose, 20 maxillary right central incisors of rats were randomly assigned to 2 groups (n=10). In group I, root surface was treated with 10-4M gallium nitrate solution for 20 min, while in group II root surface was treated with 2% sodium fluoride for 20 min. All root canals were filled with a calcium hydroxide-based paste. At 15 and 60 days after replantation, the animals were killed and the specimens were processed in laboratory for light transmission microscopy. In both groups, there was mild occurrence of ankylosis and root resorption. The connective tissue formed at the periodontal ligament area was arranged parallel to the root in most specimens in both groups and presented signs of inflammation. In group I, there was periodontal pocket formation in all specimens at 60 days, revealing lack of repair. These findings contraindicate the use of gallium nitrate for root surface treatment of teeth submitted to late replantation.     

Delayed replantation of rat teeth after use of reconstituted powdered milk as a storage medium

Abstract – Minimal extraoral dry storage period and moist storage for the avulsed tooth are identified as key steps for the treatment protocol of tooth replantation. Among the possible moist storage media, bovine milk has stood out because of its capacity of preserving the integrity of the periodontal ligament (PDL) fibers. This condition has attracted the attention to investigate the use of powdered milk, which is one of the presentation forms of bovine milk, as a feasible storage medium in cases of delayed tooth replantation. The aim of this study was to evaluate the healing process after delayed replantation of rat teeth stored in reconstituted powdered milk and long shelf‐life (ultra high temperature) whole milk. Forty maxillary right rat incisors were assigned to four groups (n = 10): group I – the teeth were extracted and immediately replanted into theirs sockets; group II – the teeth were stored for 60 min in 200 ml of freshly reconstituted powdered milk; group III – the teeth were stored for 60 min in 200 ml of long shelf‐life whole milk; group IV – the teeth were kept dry for the same time. All procedures were performed at room temperature. Next, the root canals of teeth in groups II, III, and IV were instrumented, filled with a calcium hydroxide‐based paste, and replanted into their sockets. All animals received systemic antibiotic therapy and were killed by anesthetic overdose 60 days after replantation. The pieces containing the replanted teeth were removed, fixed, decalcified, and paraffin‐embedded. Semi‐serial 6‐μm‐thick sections were obtained and stained with hematoxylin and eosin for histomorphological analysis. There was statistically significant difference (P < 0.05) between groups I and IV regarding the presence of replacement resorption and PDL remnants on root surface. The powdered milk and long shelf‐life whole milk presented similar results to each other and may be indicated as storage media for avulsed teeth.     

Calcium hydroxide mixed with camphoric p-monochlorophenol or chlorhexidine in delayed tooth replantation

This study evaluated the repair process after delayed replantation of rat teeth, using calcium hydroxide (Ca(OH)2) mixed with camphorated p-monochlorophenol (CMCP), chlorhexidine 2% (CHX), or saline as temporary root canal dressing to prevent and/or control inflammatory radicular resorption. Thirty Wistar rats (Rattus norvegicus albinos) had their right upper incisor extracted, which was bench-dried for 60 minutes. The dental papilla, the enamel organ, the dental pulp, and the periodontal ligament were removed. The teeth were immersed in 2% acidulated-phosphate sodium fluoride solution for 10 minutes. The root canals were dried with absorbent paper cones and divided into 3 groups of 10 animals according to root canal dressing used: group 1: Ca(OH)2 + saline, group 2: Ca(OH)2 + CMCP, and group 3: Ca(OH)2 + CHX 2%. Before replanting, the teeth sockets were irrigated with saline. Histological analysis revealed the presence of inflammatory resorption, replacement resorption, and ankylosis in all 3 groups. Statistical analysis showed a significant difference between group 3 and the other groups. The use of Ca(OH)2 mixed with CMCP or CHX did not show an advantage over the use of Ca(OH)2 mixed with saline in preventing and/or controlling inflammatory resorption in delayed replantation of rat teeth.     

Replantation of teeth and antibiotic treatment

Abstract Administration of antibiotics is usually recommended when a traumatically avulsed tooth is replanted, in order to prevent bacterial contamination. In the present study, permanent lateral incisors of monkeys were extracted, allowed to dry for 1 h and then replanted. Some teeth had their pulp chambers opened labially and left open for 3 wk after replantation. The monkeys were treated with antibiotics (i.m.) either at the lime of replantation or 3 wk after replantation. In some monkeys, antibiotics were placed in the pulpal cavity. Comparisons were made of the effect of endodontic treatment on periodontal healing and root resorption. The monkeys were killed 8 wk after replantation. It was found that after systemic antibiotic treatment at the time of replantation there was no inflammatory root resorption. Also, endodontic treatment at the time of replantation prevented inflammatory root resorption. When systemic antibiotic treatment was instituted 3 wk after (he replantation, there was no reduction of the inflammatory root resorption as compared with teeth without antibiotic treatment. Application of antibiotics in the pulp 3 wk after replantation almost completely eliminated the inflammatory resorption. In all the treatment groups where administration of antibiotics or endodontic treatment had prevented, reduced or eliminated inflammatory root resorption, 30–45% of the root surface area was ankylotic 8 wk after replantation.     

Effect of diode laser and fluoride varnish on initial surface demineralization of primary dentition enamel: an in vitro study

Summary. Introduction. Previous investigations have demonstrated improved enamel caries resistance after laser irradiation. The purpose of this in vitro study was to assess the caries‐preventive potential of 809 nm diode laser treatment of the enamel of primary teeth compared to topical fluoride application. Methods. Eighty samples of sound primary teeth were embedded in plastic and stored in saline solution. The enamel surface of 80 samples was polished in an area of 2 × 2 mm. These tooth specimens were randomly assigned to one control and three test groups: (1) no treatment/control; (2) application of 0·1 mg of fluoride varnish (Duraphat^®) for 6 h; (3) diode laser application (809 nm, 140 mJ, 50 Hz, Ø 600 µm fibre, contact mode, absorber, 1 min; ORA‐LASER01^® I.S.T.); and (4) combined application – laser/fluoride varnish. Caries‐like lesions were created by pH‐cycling. After lesion formation, longitudinal sections were taken and examined by polarized light microscopy. Results. In the control group, all samples showed lesions up to 30 µm in depth. After laser application, lesions could be identified in 15 out of 20 samples. Topical fluoride treatment in groups 2 (varnish) and 4 (laser/varnish) completely inhibited the development of caries‐like lesions in all samples. Conclusion. In this in vitro investigation, topical fluoride treatment enhances the resistance of sound enamel of primary teeth more effectively than diode laser application.     

The effect of Emdogain gel on periodontal healing in replanted monkeys' teeth

OBJECTIVE: We sought to histologically evaluate the effect of Emdogain gel on periodontal healing in monkeys' teeth undergoing delayed replantation.Study design Mature monkey teeth simulating avulsion were endodontically treated before extraction. Negative control teeth (group N = 10 roots) underwent immediate replantation, whereas the rest were bench-dried for 1 hour and treated in one of the following ways before replantation: the positive control teeth (group P = 12 roots) had no further treatment; group C teeth (4 roots) had the periodontal ligament removed; group D teeth (10 roots) were treated with Emdogain gel; group E teeth (6 roots) had the periodontal ligament removed before the application of Emdogain gel; and group F teeth (7 roots) had the periodontal ligament removed, the root surface conditioned, and Emdogain gel applied. Periodontal healing was evaluated after 16 weeks by undertaking histomorphometric analysis. RESULTS: The Kruskal-Wallis and Mann-Whitney U tests revealed that group N teeth had a statistically higher occurrence of complete healing than did all other groups, whereas group P was not significantly different in any of the healing categories from D, E, and F, the groups in which Emdogain gel was used. Group C teeth had a significantly higher occurrence of replacement root resorption than did the teeth in groups P and F-but were not significantly different from teeth in groups D and E. CONCLUSION: Emdogain gel did not appear to significantly reduce replacement resorption in monkeys' teeth that had undergone delayed replantation.