Tooth Avulsion

Tooth Avulsion

Orofacial injuries, including dental injuries, often occur as a result of trauma related to accidents or participation in sports activities. Dental injuries include tooth fracture, displacement, and avulsion, when the periodontal ligament (PDL) is severed and the tooth is completely displaced from its socket.1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9. Tooth avulsion accounts for between 0.5% and 3% of all dental injuries and may be accompanied by fracture of the alveolus.1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9.^,2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96. Higher rates of dental trauma are found for individuals with special needs. In an assessment of more than 500 children and adolescents, 39.6% and 30.4% of individuals with cerebral palsy and autism, respectively, were affected by dental trauma. Tooth avulsion accounted for almost a quarter of injuries to primary teeth.3Bagattoni S, Sadotti A, D’Alessandro G, Piana G. Dental trauma in Italian children and adolescents with special health care needs. A cross-sectional retrospective study. Eur J Paediatr Dent 2017;18:23-6.

The sequelae of tooth avulsion include the physical trauma, as well as the impact that this emergency may have on quality of life.4Lee JY, Divaris K. Hidden consequences of dental trauma: The social and psychological effects. Pediatr Dent 2009;31:96-101. Management of avulsed teeth begins at the site of the accident and includes reassurance of the affected person. What occurs next can determine the ultimate outcome of treatment for these injuries.

Management of Primary Tooth Avulsion

Replantation of avulsed primary teeth is not recommended.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96. Patients with avulsed primary teeth should be assessed for damage to adjacent soft and hard tissues, and intraoral radiographs taken to verify that the tooth was completely avulsed.1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9. Depending on the child’s age, space maintenance therapy may be required to preserve space for erupting permanent teeth.

Management of Permanent Tooth Avulsion

Immediate replantation is typically the treatment of choice for avulsed permanent teeth.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96. (Figure 1) The tooth must be handled only by its crown. If soiled, the tooth should be gently rinsed under cold running water for up to 10 seconds before replantation. After replantation, the patient must bite down on a clean handkerchief, or other clean cloth, held against the tooth.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96. Emergency treatment provided in the dental office or emergency clinic includes debridement of the area with water spray, saline, or chlorhexidine, suturing any lacerations, radiographic verification that the replanted tooth position is correct, and provision of a flexible splint that the patient wears for up to 2 weeks.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96.^,5American Association of Endodontists. The recommended guidelines of the American Association of Endodontists for the treatment of traumatic dental injuries, 2013. Available at: http://www.nxtbook.com/nxtbooks/aae/traumaguidelines/index.php#/4 Advice on home care should be provided as well as antibiotics if indicated and a referral for a tetanus booster if current protection through prior vaccination cannot be confirmed.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96. (Table 1) Replantation may be contraindicated for patients with severe dental caries, periodontal disease, severe mental disability or who are medically compromised.1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9.^,2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96. Severe injury to the alveolus can also preclude replantation.1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9.

Figure 1. Avulsed tooth (pending image)

Delayed Replantation

If immediate replantation is not possible, the tooth should be placed in a suitable storage medium within 5 minutes,1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9. and the patient transferred to the dental office, a dental emergency clinic or a hospital emergency department. If the extraoral dry time was less than 60 minutes (i.e., the length of time before the tooth was placed in an appropriate storage medium after avulsion), the replantation protocol and follow-up is similar to immediate replantation except that a splint is worn for 4 weeks rather than 2 weeks. If the extraoral dry time was 60 minutes or longer, the PDL will be necrotic and non-viable soft tissue must be carefully removed from the root before replantation.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96.

Endodontic Treatment

Endodontic treatment is recommended 7 to 10 days following replantation for teeth with closed apices or may be provided prior to replantation if the extraoral dry time was an hour or longer.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96. In teeth with open apices, pulp revascularization may occur following replantation, and root formation may continue. Therefore, in the absence of pulpal necrosis, endodontic therapy should be avoided and can be performed later if required.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96.^,5American Association of Endodontists. The recommended guidelines of the American Association of Endodontists for the treatment of traumatic dental injuries, 2013. Available at: http://www.nxtbook.com/nxtbooks/aae/traumaguidelines/index.php#/4

Prognosis for Replanted Teeth

Immediate replantation offers the best prognosis, and a higher survival rate has been found for teeth with closed versus open apices.6Petrovic B, Marković D, Peric T, Blagojevic D. Factors related to treatment and outcomes of avulsed teeth. Dent Traumatol 2010;26(1):52-9. doi: 10.1111/j.1600-9657.2009.00836.x. The most common adverse events are ankylosis and root resorption, with loss of the tooth. Delayed replantation increases the risk of these adverse outcomes.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96.^,4Lee JY, Divaris K. Hidden consequences of dental trauma: The social and psychological effects. Pediatr Dent 2009;31:96-101. In growing children, ankylosis typically results in infrapositioning of the tooth, and disturbed alveolar and facial growth.1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9.

Factors affecting the prognosis include handling of the tooth, degree of root contamination, extraoral dry time, PDL cell viability, the storage medium and duration of immersion, integrity of the root surface and root maturity.1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9.^,2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96.^,4Lee JY, Divaris K. Hidden consequences of dental trauma: The social and psychological effects. Pediatr Dent 2009;31:96-101.^,7Poi WR, Sonoda CK, Martins CM, Melo ME, Pellizzer EP, de Mendonça MR, Panzarini SR. Storage media for avulsed teeth: a literature review. Braz Dental J 2013;24(5):437-45.^,8Andreasen JO, Borum MK, Jacobsen HL, Andreasen FM. Replantation of 400 avulsed permanent incisors. 4. Factors related to periodontal ligament healing. Endod Dent Traumatol 1995;11(2):76-89. Immersing teeth in 2% sodium fluoride for 20 minutes prior to replantation may reduce the risk of resorption over a 5-year period,1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9.^,2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96. and experimentally it was found that recombinant basic fibroblast growth factor may promote PDL formation.9Tuna EB, Arai K, Tekkesin MS, Seymen F, Gencay K, Kuboyama N, Maeda T. Effect of fibroblast growth factor and enamel matrix derivative treatment on root resorption after delayed replantation. Dent Traumatol 2015;31(1):49-56. doi: 10.1111/edt.12141. In addition, pulpal revascularization of teeth with open apices was found in one study to be more likely if immersion in a suitable medium lasted less than 5 minutes, and may be accelerated by immersing teeth in doxycycline solution prior to replantation.1American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9.^,10Andreasen JO, Borum MK, Jacobsen HL, Andreasen FM. Replantation of 400 avulsed permanent incisors. 2. Factors related to pulpal healing. Endod Dent Traumatol 1995;11(2):59-68.^,11Andreasen JO, Borum MK, Andreasen FM. Replantation of 400 avulsed permanent incisors. 3. Factors related to root growth. Endod Dent Traumatol 1995;11(2):69-75.

Storage Media

An ideal storage medium would be readily available, biocompatible, antimicrobial, maintain PDL cell viability and periodontal fibers, promote cell proliferation and supply nutrients.12Is Khinda V, Kaur G, G SB, Kallar S, Khurana H. Clinical and practical implications of storage media used for tooth avulsion. Int J Clin Pediatr Dent 2017;10:158-65. Current recommendations are to store avulsed teeth in Hanks balanced salt solution (HBSS) or in tissue culture/transport medium, when possible.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96.^,13Hasan MR, Takebe H, Shalehin N, Obara N, Saito T, Irie K. Effects of tooth storage media on periodontal ligament preservation. Dent Traumatol 2017;33:383-92. However, these and commercial storage media are typically not available where tooth avulsion emergencies occur. As an alternative, it is recommended that milk or another suitable storage medium be used.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96.^,5American Association of Endodontists. The recommended guidelines of the American Association of Endodontists for the treatment of traumatic dental injuries, 2013. Available at: http://www.nxtbook.com/nxtbooks/aae/traumaguidelines/index.php#/4 In a review of the literature, regular pasteurized whole milk was found to be the most frequently recommended alternative storage medium and to offer the best prognosis.7Poi WR, Sonoda CK, Martins CM, Melo ME, Pellizzer EP, de Mendonça MR, Panzarini SR. Storage media for avulsed teeth: a literature review. Braz Dental J 2013;24(5):437-45. Milk is also readily available. The patient’s saliva is relatively ineffective at maintaining cell viability but may be used if a more suitable medium is not available.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96.^,5American Association of Endodontists. The recommended guidelines of the American Association of Endodontists for the treatment of traumatic dental injuries, 2013. Available at: http://www.nxtbook.com/nxtbooks/aae/traumaguidelines/index.php#/4 In addition, teeth should only be stored in water as a last resort, i.e., if it is the only option for wet storage.

Several studies have evaluated other potential storage media. In one study, coconut water was more effective than buttermilk, but less effective than cow’s milk.14Kokkali VV, Bendgude V, Sharangpani G. Comparative evaluation of post-traumatic periodontal ligament cell viability using three storage media. Eur Arch Paediatr Dent 2017;18:209-14. In a second study, tooth storage in coconut milk did not maintain cell viability.15Saini D, Gadicherla P, Chandra P, Anandakrishna L. Coconut milk and probiotic milk as storage media to maintain periodontal ligament cell viability: an in vitro study. Dent Traumatol 2017;33(3):160-4. HBSS, an HBSS-based commercially available medium and a Special Cell Culture Medium (SCCM) were all effective in maintaining cell viability for up to 6 hours.16Lee W, Stover S, Rasoulianboroujeni M, Sherman K, Fahimipour F. The efficacy of commercial tooth storage media for maintaining the viability of human periodontal ligament fibroblasts. Int Endod J 2018;51:58-68. Other research suggests that egg, propolis and coconut milk may be suitable alternatives for up to 3 hours at 20°C and 5°C. With longer immersion, only HBSS, skimmed and whole milk were effective and, after 24 hours immersion at 5°C, HBSS was less effective than milk.17de Souza BD, Bortoluzzi EA, Reyes-Carmona J, Dos Santos LG, Simões CM, Felippe WT, Felippe MC. Effect of temperature and seven storage media on human periodontal ligament fibroblast viability. Dent Traumatol 2017;33(2):100-5. doi: 10.1111/edt.12311.

Knowledge about Tooth Avulsion

Dental professionals are usually not present when tooth avulsion occurs, and a dental setting may not be the first clinical point of care. However, survey findings highlight varying levels of knowledge about tooth avulsion among parents, teachers and healthcare professionals. In separate surveys, 91% of Turkish parents and 75% of European parents and teachers reported that they lacked knowledge about tooth avulsion emergencies.18Ozer S, Yilmaz E, Bayrak S, Tunc ES. Parental knowledge and attitudes regarding the emergency treatment of avulsed permanent teeth. Eur J Dent 2012;6(4):370-5.^,19Tiano L, Barbiero S, Avato FA, Bergmann M, Gaudio RM. Management of facial trauma with tooth avulsion in children and adolescent, investigation on knowledge of parents and teachers. Eur J Pub Health 2015;25(Suppl 3): October 2015. https://doi.org/10.1093/eurpub/ckv176.241 In Virginia, 54% of emergency department physicians suggested milk as a storage medium prior to delayed replantation, while 96% knew that a storage medium was required.20Phelps JLB. Virginia emergency department physician knowledge of the emergent treatment of avulsed teeth. Thesis, Virginia Commonwealth University, 2008. Available at: https://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=1844&context=etd. Fifty-one percent of nurses and 37% of physicians in an Indian survey did not believe tooth avulsion required immediate care, while 40% and 20%, respectively, suggested milk as a storage medium.21Kotha A, Kumar YV, Prathima V, Pratibha B, Ankitha CH. Evaluation of awareness of first aid of avulsed tooth among physicians and nurses of hospital emergency departments: A short survey. Int J Comm Health Med Res 2017;3(3):74-7. Further, only 7% of Polish school nurses in one survey knew that they could replant avulsed teeth and 16% would choose milk as a storage medium.22Baginska J, Rodakowska E Milewski R, Wilczynska-Borawska M, Kierklo A. Polish school nurses’ knowledge of the first-aid in tooth avulsion of permanent teeth. BMC Oral Health 2016;16:30. Among newly-graduated physicians in Kuwait, 73%, 27% and 83%, respectively, had ‘some’ knowledge, a ‘low’ level of knowledge, or had not received any training on tooth avulsion emergencies.23Abu-Dawoud M, Al-Enezi R, Andersson L. Knowledge of emergency management of avulsed teeth among young physicians and dentist. Dental Traumatol 2008;23(6):348-55. Newly-graduated dentists demonstrated high or moderate levels of knowledge.

Conclusions

Favorable treatment outcomes following tooth avulsion are dependent on proper management of these emergencies. Parents, patients, teachers, caregivers and healthcare professionals should be educated on the management of tooth avulsion emergencies. Dental professionals can help educate the public and other healthcare professionals on these emergencies, and can also provide immediate advice remotely by phone or the internet.2Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96. In addition, continuing education on this topic is required for all healthcare professionals, and more research is required on techniques and alternative storage media that will improve the prognosis for replanted teeth.

References

• 1.American Association of Pediatric Dentistry. Guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Reference Manual 2013;39(6):412-9.
• 2.Andersson L, Andreasen JO, Day P, Heithersay G, Trope M, DiAngelis AJ, Kenny DJ, Sigurdsson A, Bourguignon C, Flores MT, Hicks ML, Lenzi AR, Malmgren B, Moule AJ, Tsukiboshi M. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Dent Traumatol 2012;28:88-96.
• 3.Bagattoni S, Sadotti A, D’Alessandro G, Piana G. Dental trauma in Italian children and adolescents with special health care needs. A cross-sectional retrospective study. Eur J Paediatr Dent 2017;18:23-6.
• 4.Lee JY, Divaris K. Hidden consequences of dental trauma: The social and psychological effects. Pediatr Dent 2009;31:96-101.
• 5.American Association of Endodontists. The recommended guidelines of the American Association of Endodontists for the treatment of traumatic dental injuries, 2013. Available at: http://www.nxtbook.com/nxtbooks/aae/traumaguidelines/index.php#/4
• 6.Petrovic B, Marković D, Peric T, Blagojevic D. Factors related to treatment and outcomes of avulsed teeth. Dent Traumatol 2010;26(1):52-9. doi: 10.1111/j.1600-9657.2009.00836.x.
• 7.Poi WR, Sonoda CK, Martins CM, Melo ME, Pellizzer EP, de Mendonça MR, Panzarini SR. Storage media for avulsed teeth: a literature review. Braz Dental J 2013;24(5):437-45.
• 8.Andreasen JO, Borum MK, Jacobsen HL, Andreasen FM. Replantation of 400 avulsed permanent incisors. 4. Factors related to periodontal ligament healing. Endod Dent Traumatol 1995;11(2):76-89.
• 9.Tuna EB, Arai K, Tekkesin MS, Seymen F, Gencay K, Kuboyama N, Maeda T. Effect of fibroblast growth factor and enamel matrix derivative treatment on root resorption after delayed replantation. Dent Traumatol 2015;31(1):49-56. doi: 10.1111/edt.12141.
• 10.Andreasen JO, Borum MK, Jacobsen HL, Andreasen FM. Replantation of 400 avulsed permanent incisors. 2. Factors related to pulpal healing. Endod Dent Traumatol 1995;11(2):59-68.
• 11.Andreasen JO, Borum MK, Andreasen FM. Replantation of 400 avulsed permanent incisors. 3. Factors related to root growth. Endod Dent Traumatol 1995;11(2):69-75.
• 12.Is Khinda V, Kaur G, G SB, Kallar S, Khurana H. Clinical and practical implications of storage media used for tooth avulsion. Int J Clin Pediatr Dent 2017;10:158-65.
• 13.Hasan MR, Takebe H, Shalehin N, Obara N, Saito T, Irie K. Effects of tooth storage media on periodontal ligament preservation. Dent Traumatol 2017;33:383-92.
• 14.Kokkali VV, Bendgude V, Sharangpani G. Comparative evaluation of post-traumatic periodontal ligament cell viability using three storage media. Eur Arch Paediatr Dent 2017;18:209-14.
• 15.Saini D, Gadicherla P, Chandra P, Anandakrishna L. Coconut milk and probiotic milk as storage media to maintain periodontal ligament cell viability: an in vitro study. Dent Traumatol 2017;33(3):160-4.
• 16.Lee W, Stover S, Rasoulianboroujeni M, Sherman K, Fahimipour F. The efficacy of commercial tooth storage media for maintaining the viability of human periodontal ligament fibroblasts. Int Endod J 2018;51:58-68.
• 17.de Souza BD, Bortoluzzi EA, Reyes-Carmona J, Dos Santos LG, Simões CM, Felippe WT, Felippe MC. Effect of temperature and seven storage media on human periodontal ligament fibroblast viability. Dent Traumatol 2017;33(2):100-5. doi: 10.1111/edt.12311.
• 18.Ozer S, Yilmaz E, Bayrak S, Tunc ES. Parental knowledge and attitudes regarding the emergency treatment of avulsed permanent teeth. Eur J Dent 2012;6(4):370-5.
• 19.Tiano L, Barbiero S, Avato FA, Bergmann M, Gaudio RM. Management of facial trauma with tooth avulsion in children and adolescent, investigation on knowledge of parents and teachers. Eur J Pub Health 2015;25(Suppl 3): October 2015. https://doi.org/10.1093/eurpub/ckv176.241
• 20.Phelps JLB. Virginia emergency department physician knowledge of the emergent treatment of avulsed teeth. Thesis, Virginia Commonwealth University, 2008. Available at: https://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=1844&context=etd.
• 21.Kotha A, Kumar YV, Prathima V, Pratibha B, Ankitha CH. Evaluation of awareness of first aid of avulsed tooth among physicians and nurses of hospital emergency departments: A short survey. Int J Comm Health Med Res 2017;3(3):74-7.
• 22.Baginska J, Rodakowska E Milewski R, Wilczynska-Borawska M, Kierklo A. Polish school nurses’ knowledge of the first-aid in tooth avulsion of permanent teeth. BMC Oral Health 2016;16:30.
• 23.Abu-Dawoud M, Al-Enezi R, Andersson L. Knowledge of emergency management of avulsed teeth among young physicians and dentist. Dental Traumatol 2008;23(6):348-55.