international magazine of oral implantology

22 I implants1_2011 I special _ endo-implant algorithm chamber ceiling and pulp stones can be peeled away withafootballdiamondburtoidentifygrosslythepri- maryorifices. Micro-etching (Danville Materials) the floor of the chamber, perhaps the most underused of all access tools, is invaluable in the exposure of fusion lines and groovesinordertoidentifyaccessoryorifices.Trough- ing with ultrasonic tips of any design is used solely to trace fusion lines, not affect gross removal. The use of ultrasonics to ‘jackhammer’ pulp stones is simply too risky as one approaches the floor of the chamber, par- ticularly if there are no water ports on the tips. Orifice lengthening and widening enables straight-line glide pathtotheapicalthird.Thestrategicobjectiveisnotto impede the file, stainless-steel or NiTi rotary along the axialwallswithminimaldentineremoval(Figs.8a&b). It is equally important to produce a high-quality coronal restoration at the time of sealing the root- canal system.21, 22 Despite research supporting the effectiveness of coronal barriers and the need for immediate placement as a component of the com- pletionphaseofroot-canaltreatment,auniversallyac- ceptedprotocoldoesnotexist. Schwartz and Fransman described a clinical strat- egyforcoronalsealingoftheendodonticaccessprepa- rationthatliststhefollowingconsiderationsinthepro- tocol: use bonded materials (4th generation (three- step)resinadhesivesystemsarepreferredbecausethey provide a better bond than the adhesives that require fewersteps);theetchandrinseadhesivesarepreferred to self-etching adhesive systems, if a eugenol-con- tainingsealerortemporarymaterialisused;self-etch- ing adhesives should not be used with self-cure or dual-cure restorative composites. When restoring ac- cess cavities, the best aesthetics and highest initial strength are obtained with an incremental fill tech- nique using composite resin. A more efficient tech- nique that provides acceptable aesthetics is to bulk fill withaglassionomermaterialtowithin2to3mmofthe cavo-surface margin, followed by two increments of light-cure composite and, if retention of a crown or bridge abutment is a concern after root-canal treat- ment, post placement increases retention to greater thantheoriginalstate(Fig.9).23 _Irrigation Thecomplexanatomyoftheroot-canalspacepres- ents a daunting challenge to the clinician who must thoroughly debride and disinfect the corridors of sep- sisinordertoachieveasuccessfultreatmentoutcome (Fig.10).Inaddition,theabsenceofacell-mediatedde- fence (phagocytosis, a functional host response) in necrotic teeth means the micro-organisms residual in tubuli, cul-de-sacs and arborisations are mainly af- fected by the redox potential (reduction potential re- flects the oxidation—reduction state of the environ- Figs. 5a & b_Flat-field sensors provide a sense of the extent of osseous pathology; however, the peri-apical radiographic image corresponds to a 2-D aspect of a 3-D structure. Peri-apical lesions confined within the cancellous bone are usually not detected. Thus, a lesion of a certain size can be detected in a region covered by a thin cortex, whereas the same size lesion cannot be detected in a region covered by thicker cortex. Tables I & II_Derived from Baumgartner (Antibiotics and the Treatment of Endodontic Infections, Summer 2006). Fig. 5a Fig. 5b Indications for adjunctive antibiotics Fever > 100°F Malaise Lymphadenopathy Truismus Increased swelling Cellulitis Osteomyelitis Conditions not requiring adjunctive antibiotics Pain w/o signs and symptoms of infection Symptomatic irreversible pulpitis Acute periradicular periodontitis Teeth with negrotic pulps and radiolucency Teeth with a sinus tract (chronic periradicular absess) Localised fluctuant swellings Table I Table II