Rationale for Replantation
- Surgical access: The position of mandibular second molars makes access difficult in regard to ideal retraction of the lips and soft tissue. Furthermore, second molars are lingually inclined and due to the external oblique ridge there is an median average of 7.34 – 8.51mm of bone covering the roots (3) (Fig 1). Maxillary second molars also present complications in regard to access. The roots are often in the antral sinus therefore obviating the surgical protocol required.
- Proximity to anatomic structures: Mandibular teeth may spatially approximate the mental foramen or encroach upon the IAN. As a result, a microsurgical approach may induce a partial or permanent paresthesia. Maxillary molar roots are often in the antral sinus. Surgery can force debris to enter the sinus with the possibility of ensuent post operative complications. There are clinical situations where the source of sepsis is a large lateral canal or plexus of lateral canals. Accessing these portals of exit surgically necessitates removal of excess amounts of tooth structure, if they can be accessed at all.
- Patient management: There are those who are physically unable to sit through a surgery; patients with physical handicaps, those that are medically compromised or have limited opening or trismus issues. There are patients who exhibit anxiety disorders which may obviate apical surgery; however, they may be amenable to extraction and replantation with P.O sedation techniques.
- Perforation in areas not accessible surgically: Post perforation of the buccal aspect of a palatal root. Performing microsurgical repair in such a case would mean accessing through significant depths of healthy bone, removal of healthy buccal roots simply to access the perforation. The end result may be a tooth hopelessly compromised due to a poor crown/root ratio (Fig 2).
Case Selection: The tooth must be extractable without fracturing any of the root structure. Teeth with fused roots are good candidates for extraction; however, they will often require a splint to stabilize them after replantation. A splint can be as simple as placing 2 sutures either straight across the occlusal surface of the replanted tooth or crossing the tooth like the letter X. A more rigid mechanism is provided by GlasSpan Splint (GlasSpan Inc., Exton, PA) which is a hollow fiberglass rope filled with flowable composite which is placed into a groove connecting the tooth being extracted with a proximal tooth. The perfect candidate for replantation is a tooth with relatively straight roots and a substantial volume of inter-septal bone. These teeth can be removed easily and when replanted will not need to be splinted. Splints should be avoided if possible, as they can promote replacement resorption which could lead to failure. Teeth with dilacerated roots are not suitable candidates for replantation (Fig 3).
- Keep the forceps off the cementum: The forceps should be placed on enamel above the CEJ. A gentle buccal and lingual rocking motion should be used in addition to rotational force. The concept is to cause an acute inflammatory reaction in the PDL space while expanding the buccal and lingual/palatal plates of bone. Cow horn forceps should not be used as these will damage the furcation area.
- Maintain the viability of the PDL: The extracted tooth should remained bathed in Hanks Balanced Solution (HBSS) which will maintain the life of the PDL for up to 30 minutes (4). If HBSS is difficult to obtain, then a viable substitute can be Pedialyte (5) which can be bought in any supermarket or drugstore (Fig 4).
- Avoid curettage of the socket: When a tooth is extracted, the PDL is severed, leaving viable PDL along the inner walls of the socket. This must not be removed as the remaining PDL will help with re-attachment of the replanted tooth (6). Most, if not all of the granulation tissue comes out attached to the extracted tooth. If some tissue remains in the socket, remove it with college pliers or a surgical aspirator.
- Once the tooth has been successfully exarticulated, a high speed bur is used to perform the apical resection and #330 FG Pear Carbide for root end preparation. The retro-sealing material is bio-ceramic root end filling [BC RRM Putty™] (Brasseler USA, Savannah, Georgia). Throughout the procedure, the tooth is kept moist with HBSS.
- After replanting, the cortical plates of bone are manually compressed. The patient is asked to occlude firmly on 2X2 gauze or cotton roll while post operative radiographs are taken and post operative instructions given. At this juncture, the decision regarding splinting can be made based upon the stability demonstrated (Fig 5).
- The patient should be rinsing with chlorhexidine starting 48 hours before the replantation procedure and advised to continue this for 7-10 days afterwards. A non-steroidal anti-inflammatory medication is given PO one hour prior to the procedure and the regimen sustained for 72 hours post operatively. There is no evidence that antibiotics are required; however, this is a personal choice for the clinician.
Intentional replantation has been written about for years in various dental journals; the degrees of success reported have shown a wide range. Torabinejad did a systematic review of articles from 1966 – 2014 and came up with a success rate for intentional replantation of 88% (7). With this in mind and by following the above mentioned protocol, logically, replantation should not be considered a procedure of last resort. Rather it should be recognized as a viable solution to preserving a natural tooth (Figs 6,7).
- Andreasen J, Pitt Ford T. A radiographic study of the effect of various retrograde fillings on periapical healing after replantation. Dent Traumatol 1994;10(6): 276−281.
- Cho SY, Lee Y, Shin SJ, et al. Clinical Research Retention and Healing Outcomes after Intentional Replantation. J Endo June 2016;42(6):909–915
- Jin GC et al. Buccal Bone Plate Thickness of the Asian People. June 2005;31(6):430-434
- Trope M, Friedman S. Periodontal health of replanted dog teeth stored in Viaspan, milk and Hank’s balanced salt solution. Dent Traumatol October 1992;8(5):183-188
- Macway-Gomez S, Lallier TE. Pedialyte Promotes Periodontal Ligament Cell Survival and Motility. J Endodon February 2013;39(2):202-207
- Kawanami M et al. Periodontal healing after replantation of intentionally rotated teeth with health and denuded root surfaces. Dent Traumatol June 2001;17(3):127-133
- Torabinejad M Survival of Intentionally Replanted Teeth and Implant-supported Single Crowns: A Systematic Review. J Endo July 2015;41(7):992-998