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Dental Tribune Middle East & Africa Edition | 1/2017 23 taken and the copings picked up using im- pregum impression material (Fig. 11). The de- finitive crown and bridgework was then con- structedandcemented(Figs.12,13). MobileTeeth An additional difficulty when taking impres- sionsisiftheteethorsomeoftheteetharemo- bile. The force of seating the impression mate- rialontotheteethevenwithlightandmedium bodypolyvinylsiloxanematerialcanmovethe teethintopositionsthatarenotinaneutralpo- sition.Thusthemastermodelwillnotreplicate the natural position of the teeth and inaccura- cieswillariseinthefinalrestoration. In order to alleviate the discrepancy between themastermodelandthenaturalposition,du- ralay bonnets are used. If not, then bridgework oftenwillnotfitpassively;theocclusionwillbe incorrect and need major alteration; contact points may be open or tight and margins will notfit. Casestudy2showsacaseofaladywithmobile teeth who opts for a Lindhe/Nyman bridge ratherthanimplants(Figs.14-23).Afulldescrip- tionofthistypeofbridgewillfollowinthenext partoftheseries. TeethandImplants A further use for the duralay bonnets is when there are teeth and implants in the same jaw that need restoration. The standard way of restoring implants is by the use of pick up im- pression copings onto the head of the implant. In order that the crowns on the implants and ontheteethcanbemadetogether(ratherthan risking problems of colour matching if mak- ing the crowns first on the natural teeth and then at a later stage matching the crowns on the implants) duralay bonnets can be made on the teeth as previously described. These are fit- ted onto the prepared teeth and standard im- plant pick up impression copings placed onto Fig.21:Mastermodelwithdies Fig.29:Duralaybonnetswithcoat hangerwire Fig.25:Upper teethprepared Fig. 23:Upper and lower final bridges on fully adjust- ablearticulator Fig.27:Silverdies Fig.22:Fullupperandsplintedbridge Fig. 30: Duralay bonnets plus implant impression copings Fig.26:Upperimplantsplaced Fig.24:Uppermissing teeth Fig.28:Duralaybonnetsareusedforjawregistration ◊Page22 ÿPage24 RESTORATIVE Dental Tribune Middle East & Africa Edition | 1/201723