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Dental Tribune Middle East & Africa No. 4, 2016

Dental Tribune Middle East & Africa Edition | 4/2016 16 RESTORATIVE Advanced Restorative Techniques and the Full / Partial Mouth Reconstruction. Articulator Selection and Clinical Stages. Part 4 ByProf.PaulTipton,UK A highly respected specialist in Pros- thodontics, Paul has written many articles for the dental press and is an expert lecturer in his field with Tipton Training Academies in Man- chester, Leeds, London and Dublin. After gaining his Masters Degree in Conservative Dentistry in 1989, he wasawardedtheDiplomainGeneral Dental Practice by the Royal College of Surgeons four years later and re- ceived Specialist status in Prostho- dontics in 1999 from the GDC. An ex-professional cricketer with Lan- cashire County Cricket Club, he is currently the President of the British AcademyofImplantDentistry. Heis one of the UK’s most successful den- tal teachers in the fields of Restora- tive,CosmeticandImplantDentistry overthelast20yearswithmorethan 2000 dentists completing a year long certificate courses from one of the Tipton Training Academies ( Introduction Thefullmouthor partialreconstruc- tion is one of the most challenging procedure in Restorative Dentistry. In order to successfully restore and maintain teeth, the dentist must find out why the teeth arrived at this state of destruction. Tooth wear can result from abrasion, attrition, and erosion as well as iatrogenic prob- lems with previous restorations. Re- search has shown that these mecha- nisms rarely act alone and there is nearly always a combination of the processes. Evaluation and diagno- sis should account for the patient’s diet, the present state of the occlu- sion and dental history. Emphasis must be placed on the evaluation of occlusal prematurities preventing condylar seating in RAP. Factors that may contribute to parafunctional habits or bruxism are important to understand and manage in order to successfully restore and maintain the newly restored dentition. When there is a complete understanding of the etiology of the definition’s present state a treatment plan can be established, taking into account the number of teeth to be restored, condylar position, space availability, the vertical dimension of occlusion (VDO), the choice of restorative ma- terial and the choice of articulator andwaysofprogrammingit. ArticulatorSelection There is a large choice when assess- ingwhattypeofarticulatoriscorrect for the patient and restoration. In terms of classification, articulators rangefromhandheldcastsorsimple hingearticulatorstofixedcondyleor average value articulators to semi- adjustableandtofully-adjustable. When dealing with the complex- ity of the full mouth or partial re- construction the choice narrows to average value v semi-adjustable v fully-adjustable. The accuracy of the articulator also depends upon how it is used and programmed. All of these articulators require the use of face-bow, arbitrary or kinematic (to record the true hinge axis) to mount the upper cast. Mounting the lower cast to upper cast is then done with a individual jaw registration taken at an open vertical if mounting around RAP and closed vertical if mounting aroundICP. Finally with the semi-adjustable and fully-adjustable, programming of the posterior (condylar) determi- nantsofocclusioncanbedoneusing lateral and protrusive check bites, cadiax recording or by using a pan- tograph. The more adjustable the articulator the more accurate the restoration can be but all articulators have limi- tations and are only as accurate as the dentist/ technician that is using it. RestorativeStages Followingonfromthethirdarticlein this series which dealt mainly with the diagnostic stages of a full mouth reconstruction we now look at the clinical stages which will be illustrat- edbythefirstcasestudy.Thisgentle- manFig.1wasreferredfortreatment of his severe upper anterior wear. The patient was over closed and due to the wear now in a pseudo-class III edge to edge occlusion (Fig. 2). Af- ter initial diagnostic stages which included cosmetic imaging (Fig. 3), diagnostic waxing (Fig. 4) etc., the patient was ready for initial tooth preparation. ToothPreparation This will be dependent upon the type of restorative material to be used eg. PFM, scanned and milled porcelain, adhesive porcelain. Whilst the shift in recent years has been to all ceramic restorations, the PFM is often the restoration of choice as it allows a more conservative prepara- tion on both anterior and posterior teeth with only part of the gingival margin area prepared for porcelain (labial) and the rest a conservative 0.5mm light chamfer for metal (Fig. 5). There is also the added longevity in both of these areas of the mouth. The reader is referred to the work of Shillingburg for a full description of PFM crown preparation. In this instance the classic PFM crown was used to restore the upper 10 anterior teeth. Tooth preparation should be done is stages so as to maintain control of thecondylarpositionandverticaldi- mension. Providing the patient has adequate posterior stability (from amalgams, cores, prototype crown etc.) then the initial tooth prepara- tion should be the upper and lower anteriorcaninetocanineteeth. When completing a full-mouth re- construction upper and lower preparations should done together so as to be able to estab- lish ideal anterior guid- ance in both protrusive andlateralmovements. Once prepared the dentine is sealed and prototypes are relined, trimmed and fitted (Fig. 6). No impressions or jaw registrations are takenatthistime. The aim of the tooth preparation stage, is, over three long visits, ÿPage 17 Figure1:Initialsmileshowingno teeth Figure3:Cosmeticimaging Figure2:Anterior toothwearandclass3occlusiondue tolossofVD Figure4:Diagnosticwaxing Figure5:Toothpreparationanddentinebonding Figure6:Prototypesfitted Figure 7: Final restoration showing class 1 occlusion and ideal anterior guidance Figure8:Post-restorativeocclusalsplint Figure9:Finalsmile-closeup Figure10:Finalsmile-fullface Join Prof. Paul Tipton for the Restorative & Aesthetic Dentistry Certificate & Diploma Programme in Dubai

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