Pre surgical
The first mode of treatment to be considered when a perforation has been detected and confirmed at a pretreatment evaluation or during the instrumentation of a canal should be the calcium hydrox­ide apexification procedure. If, for some reason, this technique is deemed impractical or prior attempts have failed, the canal should be cleansed of all debris and filled to the best of the operator's abil­ity with thermopiasticized gutta-percha.
To ensure adequate visibility and accessibility, root wall defect repairs demand an intrasulcular flap inci­sion, elevation, and reflection. Once the root and the defect have been positively identified, sufficient bone is removed to gain complete and unrestricted access to the peripheral borders of the perforation. Once hemorrhage is controlled all granula­tion tissue and extruding canal debris is removed from the site with appropriately sized curettes and effective aspiration.
A Class I cavity is prepared in the external root wall to the full depth of the now exposed canal (Fig 1-1 a). Depending on location and access, the cavity is prepared with a long-shank carbide bur (#4, #6) in a slow-speed handpiece, or an appropriately selected ultrasonic CT tip When a metallic post has been placed in the canal, the preparation may require the use of a tungsten steel (#4) bur rotated at high speed.
Once the preparation and surgical site have been cleared and dried, a suitable root end filling material can be placed in the preparation (Fig 1-1 b). With the amount of literature currently supporting its use, it appears that mineral trioxide aggregate (MTA) is pos­sibly the most suitable reparative material. If MTA is unavailable or esthetics is a major concern, a non-staining material such as IRM or Super EBA would be satisfactory
The transportation and compacting procedures are the same as for a root end filling (see Lesson 25). The margins are burnished smooth, and the flap is reapproximated and sutured in place (Fig 1-1 c).
Postoperative instructions are provided and reviewed with the patient, parent, or guardian

 Fig 1-1 a 
                                     Fig 1-1 b                                          Fig1-1 c

Figs 1-1 a lo 1-1 c A successful root wall per­foration repair is based on ability to access the defect and prepare the Class I cavity without extensive coronal bone and/or tooth structure loss.

1. Perforation defects at or slightly below the gingi­val crest are the most difficult to repair. Repairs at this level are generally at the expense of crestal bone and likely condemn the patient to future peri­odontal problems. Unless periodontal conditions can be reasonably restored by corrective crown
I engthening or other regenerative procedures, intentional replantation with concomitant repair should be considered a more reasonable, less destructive alternative
2. When teeth have inaccessible defects eg, perfo­rations or resorptions that occur on the lingual walls of mandibular teeth) or when the destruction involves two or more surfaces of the same root, extensive bone removal would be required and would leave the patient with an irreparable peri­odontal problem. The operator should consider ele­vating and semi extracting the tooth from its socket, and turning it to a position that exposes the defect and accommodates preparatory and fill-ing procedures. This becomes a viable option because the periodontal membrane and root sur­face, having remained within the socket untouched and continuously bathed in blood throughout the procedure, experience no extraorai exposure. According to Andreason et al (1994), this is recognized as the critical determinant for success.
3. Tissue tattooing often follows amalgam root wall repairs. For esthetic reasons, buccal or labial root perforations should be sealed with a nonmetallic, nondiscoloring material such as Super EBA, IRM, or glass ionomers.
4. When the restorative procedure calls for a dowel, it is imperative the dowel space and the final dowel be prepared prior to the repair. A petro­leum jelly-coated temporary wax or acrylic pin is temporarily placed into the prepared dowel space as an internal guide. The flap is reflected and the preparation cavity is cut into the root. The repara­tive filling material is condensed against the tem­porary pin. Once the material has set, the pin is easily removed, the canal space cleaned, and the final post cemented in place. The seal is evaluated, and the flap is sutured in place (Figs 1-2a to 1-2c ).
f during pin removal the filling matenal is loos­ened and the seal broken, both the new dowel and the root filling material are removed, and the cavity preparation and filling process is repeated. The alternative is to cement a permanent post in place prior to the surgery at a depth short of that desired, and increase The risk of it loosening or fracturing while preparing the root. The risks, rewards, and prognosis must be thoroughly agreed on with the patient prior to the surgery.
5. When chrome alloy or stainless steel dowels are already in place, they are particularly difficult to cut unless high-speed tungsten steel burs are used. For this reason, the patient should be fore­warned that the cutting procedure may fracture and/or loosen the dowel or so shorten it That boTh The restoration and the tjooth will be at risk. To avoid leakage and subsequent failure, it is essen­tial the post be completely entombed within the prepared cavity (Figs 1-3a to 1-3c).
Ultrasonics do not offer a dowel cutting alterna­tive because the alloy tips do not generate enough energy to cut into most metallic dowels, and The vibrating action would most likely be sufficient to loosen the restoration.
6. Due to the cause-and-effect problems that arise from inadvertent iatrogenic incidents, the pro­cedure must be thoroughly explained to, under­stood by, and agreed on with the patient. The patient's wntten consent is kept in the record

Fig 1-2a|                               Fig 1-2b

Fig 1-2c

Figs 1-2a to 1-2c If a dowel is to be fabri­cated after the perforation repair, while preparing and filling the defect a temporary dowel should be used
Fiq 1-a                                                       Fig 1-3b

Fig 1-3c

Figs 1-3a to 1-3c If an existing dowel is inte­gral to the perforation, the approach to the defect will remain the same, but the post should be cut short of the preparation and t le 3-mm minimal retropreparation depth rule should be observed


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