implants - international magazine of oral implantology

research I plantsweresoonabandonedbecauseoffrequentim- plantfractures,mobilisation,lossofosseointegration and peri-implant bone loss. Most of these problems probablyoccurredowingtotheinadequatemechan- ical characteristics of Al2O3.13,14 More recently, ZrO2 has been introduced to den- tistryforitsgoodmechanicalpropertiesandhighbio- compatibility, combined with excellent aesthetics. While ZrO2 has been largely used and documented in prosthetic dentistry, only few studies have reported clinical experiences with zirconium implants.15,16 The aim of this article is to present a five-year fol- low-up study of a complex implant-prosthetic reha- bilitation with ZrO2 dental implants. _Case report A55-year-oldmalepatientpresentedwithpartial edentulismintheleftmaxillainregions21to26atthe DepartmentofOralSurgeryattheDentalClinicatthe University of Milan. The patient was in general good health and a non-smoker. However, lately he had had financialdifficultiesthathadledtohimtakinginade- quate care of his oral health and consequently losing teeth.Afterprofessionalhygieneandoralhygienein- structions, the patient was re-evaluated for an im- plant-prosthetic rehabilitation. His edentulism was complexowingtothelackofnumerousteethandbe- cause the alveolar process had undergone moderate resorption. Yet, it was sufficient to insert four dental implants. There was no need for an augmentation procedure and the predictable level within the gingi- valmarginalprofilewasnotconsideredaproblembe- cause of the patient’s low smile line (Figs. 1 & 2). After a diagnostic wax-up, the surgical guide was created. A mucoperiosteal flap was raised with a ver- tical releasing incision distal to tooth 1.2. Four one- piece yttria-stabilised ZrO2 (YSZ) implants (whiteSKY, bredent)wereinserted.Two4x12mmimplantswere positionedinregions2.1and2.3,andtwo4.5x12mm implants in regions 2.5 and 2.6 (Fig. 3). After the im- plant sites had been prepared, implant insertion was performed using a surgical contra-angle handpiece and then a dynamometric key, at a maximum torque of40N.Thefixtureswerescrewedinuntilthesanded surface reached the bone crest level, leaving the pol- ished part untreated at transgingival level. A heterol- ogous bone graft (Bio-Oss, Geistlich Pharma), to- getherwithadoublelayerresorbablemembrane(Bio- Gide, Geistlich Pharma), was positioned on the im- plant placed in region 2.1 because of the thin cortical wall and to reduce bone resorption. A sinus lift was performed using Summers’ osteotome technique to insert the implant with an adequate length (12 mm) in region 2.6 (Figs. 4–7). The flaps were sutured with non-absorbable 4.0 monofilament (Premilene, B. Braun).The removable partial denture was adapted in order to avoid any contacts with the implants. The patient was prescribed a soft diet, antibiotic therapywith1gamoxicillinandclavulanicacid(Lab- oratoriEurogenerici)everyeighthoursforsevendays and a 0.2% chlorhexidine mouth rinse (Corsodyl, GlaxoSmithKline)twiceadayfor15days.Thepatient attended a follow-up visit ten days later. The sutures were then removed and the implant stability was checked. The supra-gingival portion of the one-piece zirconium implant was minimally prepared with ETERNA burs (bredent) to achieve parallelism of the implant axes. Then the partial denture was replaced withatemporaryacrylicresinbridgetoenhancesoft- tissuehealingandguidethegingivalprofile(Fig.8).In the temporary phase, particular attention was given toocclusiontoensurecentriccontactthatwasaslight as possible and to avoid contacts in eccentric move- ments. After four months, the temporary bridge was re- moved. Implant stability, probing depth and gingival healthwereexamined.Furthermore,theocclusalsur- face of the temporary restoration was modified and Fig. 4_Sinus lift using Summers’ osteotome technique in region 2.6. Fig. 5_The four implants are positioned. I 07implants3_2012 Fig. 4 Fig. 5