CAD/CAM international magazine of digital dentistry No. 4, 2016

CAD/CAM 4 2016 treatment planning based on CBCT cone beam supplement | 43 Fig. 4: CBCT of both arches to evaluate bone quality, bone quantity, and anatomical limitations. notedtohaveaverticalfractureclinically.Therewas generalised heavy fremitus in her maxillary teeth and mobilities ranging from 2–3 degrees on the fol- lowing teeth: #3, 7 thru 13, 20–26 and 29 (FDI: #16, 12, 11, 21–25, 31–35, 41–42 and 45). Her compliance profile was good with her previous dentists, how- ever, she states that she has always had “issues with my gums.” The tentative treatment plan discussed at the ini- tial visit with the patient and her husband included the following diagnosis: generalised moderate to advancedperiodontitis;generalisedrecurrentcaries related to medication-related dry mouth; posterior bitecollapsewithlossofocclusalverticaldimension (“mutilated dentition”). Prognosis: all remaining teeth are hopeless. Treatment plan 1. Obtain a CBCT of both arches to evaluate bone quality,bonequantity,andanatomicallimitations (Fig. 4). 2. Articulate study models with fabrication of diag- nostic full upper denture (FUD), full lower denture (FLD) and surgical guide templates. 3. Team discussions to develop the final surgical and prosthetic treatment plan for hybrid restorations using the Straumann® Bone Level Tapered Implant (BLT) with a first molar occlusion. Utilisation of an indirect technique will be used to fabricate the converted fixed laboratory metal-reinforced pro- visionals in one day. 4. Coordination of the surgical visit (Dr Robert Levine)withtheprosthodontist’soffice(DrHarry Randel), dental laboratory (NewTech Dental Lab- oratory, Lansdale, PA), and the dental implant companyrepresentative(StraumannUSA,Ando- ver,MA).Thepatientisawareofthepossibleneed to wear one or both dentures during the healing phase if the insertion torque values are inade- quate for immediate loading. This may be due to bonequality,bonequantity,orneedforextensive bone grafting requiring a membrane technique for guided bone regeneration (GBR) and a two- stage approach. This is very important to review with all patients, especially when only four im- plantsareplannedinthemaxilla,asthedistalim- plant(s) may record poor insertion torque values duetobonequalityandquantity.Theabilitytouse longer, tapered (BLTs), and tilted implants—as in the present case—with adequate buccal bone availablefortheanticipated4.1mmimplantshelp to reduce this possibility significantly. 5. Delivery of the fixed provisionals in one day in the prosthodontist’s office. 6. Post-operativevisitseverytwotothreeweekswith the periodontist’s office for deplaquing, review of plaque control techniques and delivery of a water irrigation device at six weeks. An occlusal adjust- ment to be completed at each post-operative visit with the surgical and restorative offices, because theocclusionisverydynamicasthepatient’smus- culature continues to accept her newly restored occlusal vertical dimension (OVD). Time is also needed to stabilise her TMJ symptoms. 7. Completion of final case at least three months post-surgery. Since the patient will be spending the winter in Florida, she will commence her final treatment when she returns in the spring. 8. Periodontal maintenance every three months alternating between offices. Based on CBCT analysis it was decided to place five implants in the upper jaw at the following sites: #4(FDI:#15)(tilted),#7(FDI:#12),between#8 (FDI:#11)(midline),#10and#12(FDI:#22and #24) (tilted) after vertical bone reduction for pros- thetic room. Four implants were anticipated to be placedinthelowerjawatsites#21(FDI:#34)(tilted), #23 (FDI: #32), #26 (FDI: #42), & #28 (FDI: #44) (tilted). The anticipated position of each implant is ideally palatal in the maxilla to the original teeth and lingual to the original mandibular teeth. This is to allow for screw-access holes exiting away from the incisal edges anteriorly, and if possible, lingually to the central fossae in the posterior sextants. An additional benefit of palatal and lingual placement of each implant is that their final position will be at least 2–3mm from the anticipated buccal plates, which is beneficial for long-term bone maintenance and implant survival. If the necessary 2mm buccal bone to the final implant position is not available, then contour augmentation (bone grafting) is rec- ommended to create that dimension. The goal is to prevent buccal wall resorption over time using slowly resorbing inorganic bovine bone and a re- sorbablecollagenmembrane.Thismembraneallows easy contouring and flexibility over the graft mate- rial when wet. It is also important to evaluate tissue thickness. It is ideal to have at least 2mm of buccal flap thickness over each implant as thin tissues are associated with bone loss and recession over time. Fig. 4 42016

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