Effect of systemic antibiotic therapy on pulp repair following extrusive luxation and avulsion in a murine model: A histomorphological study.

BACKGROUND/AIM: The evidence for any benefit of systemic antibiotic therapy on pulp survival following extrusive luxation and avulsion is inconclusive. The aim of this study was to evaluate the effect of systemic antibiotic therapy with amoxycillin and tetracycline for 7 days on different aspects of dental pulp repair in a murine model. MATERIAL AND METHODS: The right maxillary incisor of 180 4 to 8-week-old male Wistar rats underwent extrusive luxation or avulsion. The animals were then treated with saline solution (control), tetracycline, or amoxicillin administered intra-gastrically for 7 days, and euthanized at 7, 15, and 30 days post-operatively. The layer of odontoblast cells, reparative dentin deposition, Hertwig's epithelial root sheath, pulp necrosis, and periapical inflammatory infiltrate were histomorphologically analyzed and scored. Mann-Whitney, Kruskal-Wallis, and Dunn tests were used to compare mean scores for the different procedures, treatments, and times (p ≤ .05). RESULTS: Significant differences were observed between luxated and avulsed teeth (p < .05). In luxated teeth, no differences were observed among treatments and times, except for more tertiary dentin deposition in the coronal third with the use of tetracycline compared with amoxicillin at 15 days (p < .05). In avulsed teeth, higher scores for the layer of odontoblast cells and lower scores for periapical inflammatory infiltrate at 7 days and pulp necrosis at 7 and 15 days were observed in the amoxicillin group compared to the saline and tetracycline groups (p < .05). At 30 days, however, no differences were observed among treatments. CONCLUSIONS: The use of systemic antibiotic therapy with tetracycline or amoxicillin for 7 days did not contribute to pulp repair following extrusive luxation or avulsion in rats. However, the results warrant further research into the use of amoxicillin for a more extended period of time in cases of avulsion.

The effect of soy and whole milk as a means to store avulsed teeth: A histometric study.

BACKGROUND/AIM: An adequate storage medium can help preserve the viability of periodontal ligament cells, favoring the periodontal ligament repair process. The aim of this study was to evaluate the repair process following the delayed replantation of teeth stored in soy milk and whole milk. MATERIAL AND METHODS: The maxillary right incisors of 27 rats were divided into three equally sized groups: Group SM (delayed replantation with storage in soy milk), whose teeth were immersed in 50 mL of soy milk for 60 minutes; Group WM (delayed replantation with whole milk), teeth were kept for 60 minutes in 50 mL of whole milk; and Group D (delayed replantation with dry storage), teeth were kept in dry conditions for the same period (negative control). Next, the teeth of the animals of all groups were replanted into their sockets. Systemic antibiotics were given to all the animals, and then, they were euthanized after 60 days. Sections were obtained and stained with hematoxylin and eosin for histomorphometric study. The presence and location of acute and chronic inflammatory processes in the epithelial insertion of the protective and insertion periodontium were evaluated, as well as the presence, extension, depth, and repair of root resorption, and the resorption and ankylosis with bone. Statistical differences between groups were analyzed using the Dunn test. RESULTS: Groups SM and WM showed similar patterns in the repair of the periodontal ligament following delayed replantation, in relation to the inflammatory process in the proximities of the epithelial insertion, inflammation and organization of the periodontal ligament, plus root and bone resorption. However, in group WM, more ankylosis was observed than in group SM. CONCLUSION: The teeth stored in soy milk and whole milk had similar periodontal repair, which shows the potential of soy milk as a storage medium before tooth replantation.

Calcific metamorphosis of pulp after extrusive luxation.

BACKGROUND/AIM: The literature on the pathogenesis of extrusive dental luxation has been focused on periodontal tissue responses, with little attention given to the pulp. The aim of this study was to evaluate the response of dental pulp of teeth following extrusive luxation in a rat model. MATERIAL AND METHODS: The maxillary right central incisors of 30 rats were extrusively luxated and repositioned after 5 minutes. The animals were euthanized after 7, 15, and 30 days to provide three groups: I, II, and III, respectively (n = 10). Histological sections were stained with H and E for histomorphometric analysis of the odontoblast layer, reparative dentin deposition, Hertwig's epithelial root sheath, pulp necrosis, and periapical inflammatory infiltrate. RESULTS: In most cases, new vascular formation occured in association with reparative dentin deposition on the root walls and within the pulp. In some cases, dentin deposition occupied the entire pulp space over time, with no other types of non-odontogenic hard tissues being observed. Pulp necrosis with the presence of periapical inflammatory infiltrate was also observed in a few cases. No statistical differences were observed among the studied groups. CONCLUSIONS: Following extrusive luxation, calcific metamorphosis of the pulp is very likely to occur.

Evaluation of the Osteoinductive Effect of PDGF-BB Associated With Different Carriers in Bone Regeneration in Bone Surgical Defects in Rats.

PURPOSE: Extensive bone defects in maxillofacial region can be corrected with autograft. However the disadvantages of this type of therapy lead to the search for new bone substitutes. Thus, we evaluated the biological behavior and osteoinductive platelet-derived growth factor type BB (PDGF-BB) associated with different carriers, by histological analysis and immunohistochemical histometric critical defects performed in rat calvaria. MATERIALS AND METHODS: Critical defects were created with 5-mm diameter calvaria of rats. Each defect was randomly divided into 8 experimental groups, evaluated at 15 and 30 postoperative days for histomorphometry and immunohistochemistry. RESULTS: The results showed new bone formation in all groups, independent of postoperative time. At 30 days, the beta-tricalcium phosphate matrix (TCP) group just did not differ from bone matrix mineralized bovine (BIO) group in the new bone formation (P = 0.1403). In none of the groups' analyzed biomaterials, growth factor stimulated increase in bone formation (P > 0.05). CONCLUSION: With the methodology used, the growth factor associated with the tested biomaterials did not induce new bone formation.

The influence of traumatic occlusion on the repair process for teeth following subluxation.

BACKGROUND/AIM: Traumatic occlusion (TO) can cause morphofunctional alterations that interfere in the homeostasis of the periodontium. The aim of this study was to assess the influence of TO on the periodontal repair process for teeth following subluxation. MATERIALS AND METHODS: Ninety Wistar rats aged 12 weeks were divided into three groups: control (C), subluxation (S) and subluxation with traumatic occlusion (S+TO). Subluxation was created with an impact force of 900 cN applied by a tensiometer and TO was created with a direct composite resin filling. Healing after two experimental periods of 7 and 21 days was assessed histologically. The Kruskal-Wallis and Dunn post hoc tests were used for group comparison. RESULTS: At 7 days, there was a significant increase in periodontal ligament (PDL) width and amorphous fundamental substance, as well as a significant bone area reduction in groups S and S+TO. After 21 days, there was a significant PDL width increase in group S+TO, and in the percentage of collagen fibres in group S, whereas group S+TO showed a 52% bone area reduction compared to the same group at 7 days. Subluxation with or without TO caused only superficial root resorption. However, only group S+TO showed damage to the repair process of resorbed root areas after 21 days. CONCLUSION: TO can increase damage to the PDL after subluxation and it can also delay the repair process after PDL damage.

Immediate tooth replantation in rats: effect of systemic antibiotic therapy with amoxicillin and tetracycline.

OBJECTIVES: The aim of this study was to evaluate the influence of systemic administration of antibiotics (amoxicillin and tetracycline) at the different phases of the repair process (7, 15, 30 days) in immediate rat tooth replantation. MATERIALS AND METHODS: Ninety rats had their incisors extracted and stored in saline for 5 min. Next, the teeth were replanted, and the animals were assigned to three groups according to the antibiotic administered by oral gavage: control group, amoxycillin group, and tetracycline group. Euthanasia was performed at 7, 15, and 30 days after replantation. RESULTS: Regardless of the evaluation period, the connective tissue underlying the epithelial attachment and the periodontal ligament showed statistically significant difference relative to the acute inflammatory infiltrate, which was more intense in the control group followed by the tetracycline group. CONCLUSION: These results point to the fact that systemic antibiotic therapy (SAT) in immediate tooth replantation is beneficial to pulpal and periodontal ligament repair and that amoxycillin is an excellent option. CLINICAL RELEVANCE: There is a lack of randomized studies assessing how the use of systemic antibiotics could influence tooth healing after immediate replantation.

Stress distribution in delayed replanted teeth splinted with different orthodontic wires: a three-dimensional finite element analysis.

AIM: The aim was to evaluate the biomechanical behavior of the supporting bony structures of replanted teeth and the periodontal ligament (PDL) of adjacent teeth when orthodontic wires with different mechanical properties are applied, with three-dimensional finite element analysis. MATERIALS AND METHODS: Based on tomographic and microtomographic data, a three-dimensional model of the anterior maxilla with the corresponding teeth (tooth 13-tooth 23) was generated to simulate avulsion and replantation of the tooth 21. The teeth were splinted with orthodontic wire (Ø 0.8 mm) and composite resin. The elastic modulus of the three orthodontic wires used, that is, steel wire (FA), titanium-molybdenum wire (FTM), and nitinol wire (FN) were 200 GPa, 84 GPa, and 52 GPa, respectively. An oblique load (100 N) was applied at an angle of 45° on the incisal edge of the replanted tooth and was analyzed using Ansys Workbench software. The maximum (σmax) and minimum (σmin) principal stresses generated in the PDL, cortical and alveolar bones, and the modified von Mises (σvM) values for the orthodontic wires were obtained. RESULTS: With regard to the cortical bone and PDL, the highest σmin and σmax values for FTM, FN, and FA were checked. With regard to the alveolar bone, σmax and σmin values were highest for FA, followed by FTM and FN. The σvM values of the orthodontic wires followed the order of rigidity of the alloys, that is, FA > FTM > FN. CONCLUSION: The biomechanical behavior of the analyzed structures with regard to all the three patterns of flexibility was similar.

Delayed tooth replantation in rats: effect of systemic antibiotic therapy with amoxicillin and tetracycline.

Systemic antibiotic therapy (SAT) has usually been recommended after tooth replantation, but its actual value has been questioned. As there are no reports in the literature about its influence on tooth replantation, the aim of this study was to evaluate the influence of systemic administration of antibiotics (amoxicillin and tetracycline) at the different phases of the repair process (7, 15, 30 days) in delayed rat tooth replantation. Ninety Wistar rats (Rattus norvegicus albinus) had their maxillary right incisors extracted and bench-dried for 60 min. The dental papilla, enamel organ, pulp tissue, and root surface-adhered periodontal ligament were removed, and the teeth were replanted. The animals received no antibiotics (n = 30) or were medicated systemically with amoxicillin (n = 30) and tetracycline (n = 30), and were euthanized after 7, 15, and 30 days. Regardless of the evaluation period, the acute inflammatory infiltrate was less intense and root resorption presented smaller extent and depth in the group treated with amoxicillin. The results suggest that SAT has a positive influence on the repair process in delayed tooth replantation and that amoxicillin is an excellent treatment option.

Osseointegration at implants placed into delayed reimplanted roots: an experimental study in dogs.

AIM: To evaluate peri-implant bone repair of implants placed into the roots of delayed reimplanted teeth, in a process of ankylosis and external replacement resorption. MATERIAL AND METHODS: The third and fourth mandibular premolars of four (4) beagle dogs were used as experimental sites. The study was divided into three stages: stage 1 - endodontic and extraction/reimplantation session, stage 2 - decrowning session and stage 3 - implant placement. Two groups were identified: (I) immediate implants, including implants installed in fresh extraction sockets of the distal roots, and (II) experimental implants, including implants installed into the retained ankylotic mesial roots. In each group, 16 implants were planned to be inserted, but only 9 immediate implants and 12 experimental implants were used for analyses. Implants were intended to heal in a submerged mode. After 4 months of healing, the animals were sacrificed and ground sections were obtained for histomorphometric evaluation. RESULTS: Eleven of the twelve implants in the experimental group were found successful regarding clinical and radiographic aspects. For immediate implants, a lower BIC% was found at the coronal portion (BIC% 1 = 42.2%) compared with the three most coronal threads portion (BIC% 2 = 55.1). Also, experimental implants presented a lower BIC% at the coronal portion (BIC% 1 = 36.9%) compared with the three most coronal threads portion (BIC% 2 = 45.3). CONCLUSION: Comparison between groups showed a higher degree of BIC% and mineralization in immediate group compared with experimental group. The differences, however, did not yield statistical significance.

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.

Expression of OPG, RANK, and RANKL proteins in tooth repair processes after immediate and delayed tooth.

This study evaluated the immunohistochemical expression of OPG, RANK, and RANKL proteins in the repair after immediate and delayed replantation of rat teeth. Fifty-six Wistar rats (Rattus norvegicus albinus) had their maxillary right lateral incisor extracted and then replanted, according to the following conditions: group I (control; n = 8), teeth were not extracted; group II (n = 16), immediate replantation; group III (n = 16), delayed replantation without treatment; and group IV (n = 16), delayed replantation after root surface treatment (periodontal ligament removal and immersion in 2% acidulated-phosphate sodium fluoride) and calcium hydroxide intracanal dressing. Rats in group I were euthanized on the first day of the experiment, while the animals in the other groups were euthanized 10 and 60 days after replantation (n = 8/period). Hematoxylin and eosin-stained sections were obtained for histological analysis. The immunohistochemical analysis revealed expression of OPG and RANKL proteins in all groups and both postreplantation times, except for group II at 60 days. In the experimental groups, RANK expression was observed only at 10 days. In conclusion, there was strong immunostaining for the OPG-RANK-RANKL system at the earlier postreplantation time, suggesting a more effective participation of these proteins at the start of the healing process, as their expression decreased at 60 days.

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

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.

A method for the geometric standardization of intraoral radiographs for long-term follow up of replanted teeth: a case report.

The interpretation of the set of radiographs taken during the follow-up period after tooth replantation might pose several difficulties, especially the inability to adequately reproduce the projection geometry of the exposures. This article describes a method for the geometric standardization of intraoral radiographs using a custom-made apparatus comprising a film-holder attached to an occlusal splint for the long-term follow up of dentoalveolar trauma. The method was applied in a patient who suffered an avulsion of the maxillary central incisors and had the teeth replanted after 4 h in saline storage. Endodontic treatment started 7 days after the trauma with changes of a calcium hydroxide intracanal medication every 15 days in the first 2 months and thereafter at 30-day intervals for 8 months. Root canal filling was carried out after this period. The radiographic exposures taken at the follow-up visits were standardized to identify the possible alterations during the repair process, such as root resorptions. A maxillary arch impression was made with alginate, and the model was cast in stone for fabrication of an acetate occlusal splint. The custom-made apparatus used for standardization of the radiographic exposures was fabricated by fixing a Rinn X-C-P film-holder and a 5-mm-long piece of 0.7-mm orthodontic wire to the occlusal splint with autopolymerized acrylic resin. Radiographs were taken at 4-month intervals, starting 10 months after replantation up to 76 months. The images were digitized and analysed using the Digora system. The length of the central incisors was determined to verify the reproduction of the projection geometry of the exposures and the orthodontic wire served to assess accuracy during length estimations in the radiographs. The method described in this article for geometric standardization of intraoral radiographs provided a consistent reproduction of the geometric exposure parameters, being indicated for use in the radiographic follow up of cases of dentoalveolar trauma.

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

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.

Functional aesthetic treatment of patient with phenytoin-induced gingival overgrowth.

Gingival overgrowth (GO) may be related to the frequent use of certain medications, such as cyclosporin, phenytoin (PHT), and nifedipine, and is therefore denominated drug-induced GO. This article reports a case of a patient who with chronic periodontitis made use of PHT and presented generalized GO. A 30-year-old man with GO was referred to the clinic of the Universidade Estadual Paulista, Brazil. The complaint was poor aesthetics because of the GO. The patient had a medical history of a controlled epileptic state, and PHT was administered as an anticonvulsant medication. The clinical examination showed generalized edematous gingival tissues and presence of bacterial plaque and calculus on the surfaces of the teeth. The diagnosis was GO associated with PHT because no other risk factors were identified. Treatment consisted of meticulous oral hygiene instruction, scaling, root surface instrumentation, prophylaxis, and daily chlorhexidine mouth rinses. After this stage, periodontal surgery was performed, and histopathologic evaluation was made. The patient has been under control for 3 years after the periodontal surgery, and up to the present time, there has been no recurrence. It can be concluded that PHT associated with the presence of irritants favored gingival growth and that the association of nonsurgical and surgical periodontal therapies was effective in the treatment of GO. Besides, motivating the patient to maintain oral hygiene is a prerequisite for the maintenance of periodontal health.

Intracanal dressing and root canal filling materials in tooth replantation: a literature review.

The prognosis of tooth replantation is usually related to the need of endodontic treatment, which has a direct relationship with the occurrence of root resorptions. Several studies have been undertaken in an attempt to prevent, delay, or treat these complications, which are the main causes of loss of replanted teeth. This literature review examines research evidence on intracanal dressings and root canal filling materials used in cases of tooth replantation. A comprehensive search was performed in the Medline/Pubmed, Bireme and Scielo full-text electronic journal databases to retrieve English-language articles referring to these topics that had been published between 1964 and 2010. Calcium hydroxide (CH) remains the usually recommended choice as an intracanal medicament in replanted teeth; however, there is evidence to support the initial use of a corticosteroid-antibiotic combination such as Ledermix paste to control potential early resorption, prior to the introduction of CH where the beneficial effect in the treatment of progressive root resorption has been well proven. Regarding root filling materials, CH-containing sealers are a good option because of their biological properties. Accurate diagnosis and adequate treatment plan may constitute very complex tasks, particularly in tooth avulsion because several variables are involved. In addition to the technical knowledge and clinical experience directed toward the quality of treatment, patient education may favorably influence the survival of replanted teeth.

Periapical tissue reactions to calcium hydroxide and MTA after external root resorption as a sequela of delayed tooth replantation.

Clinical experience has shown that most avulsed teeth are replanted after a long extra-alveolar time and dry or inadequate wet storage, causing necrosis of periodontal ligament cells. This condition invariably leads to development of external root resorption, leaving the filling material in contact with the periapical connective tissues. In this study, the periapical tissue reactions to calcium hydroxide (CH) and mineral trioxide aggregate (MTA) were evaluated after occurrence of external root resorption as an expected sequela of delayed tooth replantation. Twenty male Wistar rats (Rattus norvegicus, albinus) had their right upper incisor extracted and maintained in dry storage for 60 min. Then, the dental papilla, enamel organ, pulp tissue, and periodontal ligament were removed, and the teeth were immersed in a 2% acidulated phosphate sodium fluoride solution, pH 5.5, for 10 min. The teeth were randomly assigned into two groups (n = 10), in which the canals were filled with either a CH and saline paste (CH group) or MTA (MTA group). The sockets were irrigated with saline, and the teeth were replanted. After 80 days, it was possible to observe large areas of replacement root resorption and some areas of inflammatory root resorption in both groups. More severe inflammatory tissue reaction was observed in contact with calcium hydroxide compared with the mineral trioxide aggregate. New bone formation was more intense at the bottom of the socket in the MTA group. In conclusion, as far as periapical tissue compatibility is concerned, intracanal MTA can be considered as a viable option for root canal filling in delayed tooth replantation, in which external root resorption is an expected sequela.

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

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.

Educational Impact of Notebook Covers on the Knowledge of Sixth-Grade Primary Pupils About Tooth Avulsion and Replantation: A Randomized Trial.

BACKGROUND: Tooth avulsion is a common cause of tooth loss. However, there is a significant lack of knowledge about dental trauma and the appropriate emergency procedures to handle these cases. AIM: The aim of this study was to evaluate the educational effect of notebook covers illustrated with figures and informative texts about tooth avulsion and replantation in sixth-grade primary school pupils. MATERIAL AND METHODS: Sixth-grade pupils of two public school participated in this study. An experimental group consisting of 134 pupils received notebook covers illustrated with figures and informative texts about tooth avulsion and replantation, while a control group of 108 pupils received notebooks with neutral covers. An assessment of the educational effects on pupils was performed after 9 months, with a standardized questionnaire normally used to evaluate dental trauma. Statistical analysis was conducted with SPSS 21.0 (α = .05) for group description and comparison using chi-square and Student t tests. RESULTS: Compared with the control group, the experimental group showed statistically significant improvements in correct meaning of dental trauma (38% vs. 58.2%); procedures to follow in the case of dental avulsion (2.8% vs. 70.9%); storing the avulsed tooth in milk (18.5% vs. 76.9%); general knowledge about dental anatomy (61.1% vs. 95.5%); and the ideal time for the tooth to remain outside the mouth prior to replantation (20.4% vs. 59.7%). CONCLUSION: The use of notebook covers illustrated with figures and informative texts about dental trauma led to a significant increase in the knowledge of schoolchildren about tooth avulsion, first aid, and replantation.

Influence of a parafunctional oral habit on root fracture development after trauma to an immature tooth.

Root fractures in immature teeth are rare because the resilience of the alveolar bone is more favorable to the occurrence of luxation. This article reports a case of traumatic injury in an immature permanent tooth that progressed to root fracture, having a parafunctional oral habit as the possible modifying factor of case evolution. A 12-year-old boy presented for treatment complaining of a defective restoration and mild pain on the maxillary right central incisor. The patient had a history of crown fracture in this tooth due to trauma 2 years before. The clinical examination showed healthy gingival tissues and no abnormal tooth mobility, whereas radiographic projections revealed healthy periradicular tissues, incomplete root formation, and no visible root fracture. As pulp necrosis was diagnosed, calcium hydroxide therapy was started for canal disinfection and subsequent obturation. However, after 4 weeks of treatment, a horizontal fracture line was observed radiographically in the root's middle third. The patient denied a new traumatic injury, but revealed the habit of chewing on a pencil. Refraining from the deleterious oral habit was strongly advised, and root canal filling with mineral trioxide aggregate was performed to treat the root fracture. After 4 years of follow-up, the tooth has normal function and no abnormal mobility. Images suggestive of remodeling at the apical end of the coronal segment and replacement resorption of the apical segment are seen radiographically. This case demonstrates the need of following cases of dental trauma and the possible influence of parafunctional oral habits as modifying factors of case progression.