alternative framework design concepts for the all on 4 ... 15-drjivraj-pri1.pdf · considerably...

18 Spectrum dialogue – Vol. 14 No. 5 – May 2015

Alternative Framework Design Concepts for the All on 4™ solution.

Saj Jivraj B.D.S., MS.Ed., Mamaly Reshad B.D.S, MSc, Domenico Cascione BS, CDT. Claudio Tinti CDT

The predictability of successfulosseointegrated implantrehabilitation of the

edentulous jaw as described by PIBranemark introduced a new era ofmanagement for the edentulouspredicament. Implant rehabilitation ofthe edentulous patient re- mains oneof the most complex restorativechallenges because of the number ofvariables that affect both the estheticand functional aspect of theprosthesis.

The routine treatment for edentulismhas been complete dentures.

Epidemiological data has reportedthat the adult population in need of 1or 2 dentures would increase from 35.4million adults to in 2000 to 37.0million adults in 2020; and theresearchers warn that their estimatesmay be “significantly conservative.

Clinical studies have reported thatpatients with dentures have shownonly a marginal improvement in thequality of life when compared withimplant therapy. The common reasonsfor dissatisfaction in patients usingdentures are pain, areas of discomfort,poor denture stability and difficulty eating as well as lack of orcompromised retention capability.

Treatment planning of edentulouspatients with fixed restorations ondental implants has undergone aparadigm shift since the introduction ofgraft-less solutions.

Today, patients have optionswhereby in the right indicationcomplete rehabilitation can beaccomplished by the use of four to siximplants per arch. The huge advantageof this procedure is reduced number ofimplants and the ability to bypassextensive grafting procedures. Thisrehabilitation not only satisfiesesthetics and function but alsoconsiderably reduces costs for thepatient. This ultimately results inincreased patient acceptance and anincreased number of patients treated.Very few patients today are able toafford extensive implant rehabilitationson six to eight implants and the All on4™ or graft-less protocol is gainingpopularity as being the preferredtreatment for the edentulous patient.

In a world environment where thenumbers of edentulous patients areincreasing, there are not enoughavailable dentists trained in theseprotocols to be able to treat them.Patients are not given these optionsbecause of the dentist’s reluctance tooffer them. Reasons for this are lack ofeducation and the notion that thesetreatment protocols are notpredictable. Delivering graft-lessprotocols requires attention to detailfrom a surgical, prosthodontics andlaboratory perspective. Only throughadequate education and training willthe results compare to published dateusing conventional protocols.

Patient that present with a terminaldentition seek solutions that involve

fully implant supported fixedrestorations. From prosthodontic andesthetic standpoints these patientspresent with teeth that are inunfavourable positions. Patients withmissing posterior teeth are oftendiagnosed as having lack of posteriorsupport. With this diagnosis apresentation of splayed, supra-eruptedteeth often results. Both of these eventsmay be physiological or pathologicaland coupled with dento-alveolarcompensation.

Dento-alveolar compensation is theprocess in which the housing aroundthe tooth will undergo compensatorychanges in order to maintain occlusalcontact with the opposing dentition.As a result of these changes a lack ofrestorative space often results.Adequate restorative space is critical,and guide- lines exist depending uponthe type of prosthesis being treatmentplanned. There must be adequate spacefor bulk of restorative material that alsopermits a prosthesis design to establishesthetics and hygiene. If space islimited, re-establishing a patient’svertical dimension, altering theopposing occlusion or alveolectomyshould be considered.

With the increasing use of graft-lessprotocols, implants are often placedwhere the available bone is. As a result,the trajectory of the screw access isoften in an unfavorable position. Evenin situations where pre-angledabutments are used the clinician isoften faced with the difficult situation

of designing a framework andrestorations to satisfy the requirementsof esthetics, biomechanics and longterm function.

This article will present analternative framework design for theAll on 4™ solution.

A patient presented seekingreplacement of her existingrestorations. These restorations hadbeen fabricated according to the all on4™ protocol. Both maxillary andmandibular restorations were acrylicresin/titanium prostheses. Her chiefcomplaint was the horizontal ledgepresent in her maxillary prosthesis (Fig 1).

Poor emergence profile can occur asa result of too shallow an implantplacement or restoration at abutmentlevel when there is lack of restorative

space. It is the authors opinion thatthe additional room gained by restoringdirectly to the head of the fixture in theAll on 4™ protocol is advantageous inbeing able to gain space for contouringthe restoration so that an appropriateemergence profile exists. In thisparticular patient presentation, theimplants were placed at an angle thatwould be un-restorable for a screw-retained restoration if the estheticconcerns of the patient were to besatisfied (Fig 2). The implants had alsobeen placed too shallow. If thesituation had been corrected with pre-angled abutments two problemswould arise.

1. Lack of restorative spacecompromising the biomechanicsof the restoration

2. Display of metal from the facialsurface.

An alternative type of bar wasdesigned to address these particularconcerns

Splinted impressions were made atabutment level for the posteriorimplants and at implant level for theanterior implants. Master casts wereverified and a wax try in performed(Fig. 3). This try in confirmed jawrelation records and communicatedesthetic parameters to the patient. Lipsupport was evaluated and accepted.Based on the denture set up a milledprovisional restoration was fabricated(Fig. 4). The provisional was tested inthe patients mouth for three monthsprior to fabrication of the definitiveprosthesis. The access holes for themisaligned implants were covered usingcomposite resin. (Figs. 5,6)

Fig. 1: Horizontal ledge present in Maxillary prosthesis Fig. 2: Anterior implants placed too shallow and in non idealangulations compromising restorative space.

Fig. 3: Wax Try in to verify esthetics and contoursFig. 4: Milled provisional restorations fabricated, note position ofaccess holes

Spectrum dialogue – Vol. 14 No. 5 – May 2015 19


The definitive restoration had tosatisfy a few criteria

• Correction of the mis-alignedimplants

• Be 100% retrievable• Provide support for the cantilever.The definitive restoration (Diamart

Implant solutions™), was fabricatedusing

A. Titanium bar for primary splintingof the implants and support of thecantilever in zirconia (Fig. 7)

B. Zirconia Suprastructure forstrength and esthetics (Fig. 8)

C. Minimal layering for maximalesthetics. (Fig. 9)

Laboratory considerations fordesign

There are specific designrequirements for fabrication of

such a specific bar.

The design must maximise thestrength of each material. Theminimum dimensions (Fig. 10) have tobe satisfied.

The design takes advantage of the fitof the titanium bar and the estheticsand strength of the zirconia. Thezirconia superstructure is screwed ontothe titanium base using multi-unitabutment prosthetic screws. Withinthe zirconia substructure are titaniuminserts so when torque is applied it isdistributed to the titanium insertsrather than the zirconia. (Fig 11) Thetitanium inserts must incorporateretentive features, have sufficientheight and be conical to allow easiercementation within the zirconiastructure. These ultimately will becemented with a resin cement.

The laboratory must receive thefollowing from the clinician in orderto fabricate the definitive restorations

1. Accurate splinted impressions –The technician pours theimpressions and fabricates amaster cast. The technician willalso provide a verification jim and a two piece occlusal rim for jawrelation records.

2. Jaw relation records – technicianwill do an ideal diagnostic denturetooth set up

3. Denture tooth try in andverification of jaw relationshiprecords.

4. Fabrication of acrylic prototype.The clinician will verify contoursincial edge position and occlusion.

The acrylic prototype is scanned anda titanium substructure is digitallysubtracted from it.(Fig 12) It must havespecific dimensions and anundersurface which is convex. Thesame scan is used to mill a zirconiasuprastructure which is minimally cutback for porcelain application. Thedefinitive restoration is designed to

Fig. 5: Access holes covered using composite resin

Fig. 7: A primary titanium bar corrects the anteriorimplant angulation

Fig. 8: A secondary zirconia suprastructure in monolithic zirconia anddesigned for minimal layering of ceramics

Fig. 6: Esthetics and Phonetics verified


Fig. 9: Layering of ceramics tomaximize esthetics

Fig. 10: Minimum dimensions haveto be satisfied.

Fig. 12:Acrylic

prototype isscanned and

Zirconiasuprastructure

is milled.

Fig. 11: There are titaniuminserts within the intaglio ofthe zirconia suprastructure so

that when torque is applied it isdistributed to the titaniumrather than the zirconia.

Fig. 13: After final clinical try in Titanium inserts are bonded

Fig. 14a: Primary Titanium bar in placeFig. 14b: Close adaptation of the bar with the tissue

Fig. 14a

Fig. 14b


have occlusion in monolithic zirconia and minimally layeredwith ceramics for maximum esthetics.

A final clinical try in is performed to ensure patientsatisfaction prior to the titanium inserts being definitivelyluted into the zirconia suprastructure (Fig 13)


Fig. 16: Delivery of definitive prosthesis

Fig. 15: Try in of Zirconia suprastructure on top of titanium bar

At the delivery appointment thetitanium substructure is delivered andscrews torqued according tomanufacturer recommendations, therewill be a 0.5mm compression of thetissue by the titanium substructure.

The zirconia suprastructure is alsoscrewed in and screws torquedaccording to manufacturerrecommendations. (Figs. 14,15,16,17)

There should be minimal or noocclusal adjustment at thisappointment since the occlusion hasbeen verified at many stages.

The Diamart Implant Bridge™ hasmany advantages

1. It combines the fit of titanium withthe strength and esthetics ofzirconia

2. The titanium substructure supportsthe cantilever

3. The primary bar allows correctionof any implant trajectory

4. The restoration is 100% retrievable5. The Zirconia suprastructure can besegemented into multiple pieces

It provides solutions when theclinician is challenged with non-idealimplant angulations and allows adefinitive restoration that satisfies the

requirements of fit, esthetics andbiomecahincs whilst making therestoration retrievable.

The advantages of this prosthesisare

1. it provides the advantages of thefit of titanium and the esthetics ofzirconia

2. The restorations is 100% retrievable3. It can be CAD designed4. It can be made in multiple sectionsso that is a problem should arise theindividual section with the problemcan be addressed.


About The Authors

Domenico Cascione obtained his primary education in Bari (Italy),where he was also certified as a Dental Technologist (CDT) in 1985.From 1991 to 2004 he carried out metallurgy research becoming aspecialist in dental metallurgy. From 1986 to 2004 he was the ownerand director of Dental Laboratory in Bari (Italy). He is a MasterCeramist and also is specialized in metallurgy, implant work and

complex esthetic rehabilitation. In 2005 he holds a Bachelor of Science of the DentalTechnology degree from the University of Illinois.From 2005 to 2008 he was Research Associate and Program Director, Advanced

Training for Dental Technology at the Center for Dental Technology, the University OfSouthern California Herman Ostrow School Of Dentistry. He is a Clinical AssistantProfessor and Course Director for the Advanced Dental Morphology for the OperativeDentistry Program at the University Of Southern California Ostrow School OfDentistry. He is a winner of award 2007 Judson C. Hichey in the research category inthe Journal of Prosthetic Dentistry.He is an Editor in Chief of the Spectrum Dialogue magazine. He is the President of

OPERART LLC dental laboratory in Santa Monica California. He is author and co-author of several articles in the literature. He is the author of the Book Symbiosis: Art &Technique E-mail Address: [email protected]. [email protected]

Dr. Saj Jivraj completed his dental degree at the University ofManchester in England and his Advanced Prosthodontic training atthe University of Southern California. He is the former SectionChairman of Fixed Prosthodontics and Operative Dentistry at theUniversity of Southern California School of Dentistry. Dr. Jivraj haspublished numerous articles on Esthetic and Implant Dentistry in

peer-reviewed journals, and has presented on aspects of Implant Dentistry and AdvancedProsthodontic procedures both nationally and internationally. He is co-author of thetextbook “Treatment Planning in Implant Dentistry”, published by the British DentalAssociation. He is on the editorial board of the Journal of Esthetic and RestorativeDentistry, ad hoc reviewer for the Journal of Prosthetic Dentistry and the AssociateClinical Editor for Dental Teamwork magazine.

He currently holds a Faculty position as an Associate Clinical Professor at theUniversity of Southern California (USC) School of Dentistry; he is a Clinical teacher atthe Eastman Dental Institute in London and also is on the Board of Directors for theBritish Academy of Restorative Dentistry. He maintains a private practice limited toProsthodontics and Implant Dentistry in Oxnard and Woodland Hills, CA.

Dr. Mamaly Reshad is a Prosthodontist and the former SectionChair for Fixed Prosthodontics and Operative Dentistry at theUniversity of Southern California (USC). He qualified as a dentistin 1993 from Kings College, London University. He completed hisMaster’s in Conservative Dentistry with Distinction at the EastmanDental Institute. He obtained his training in advanced Prosthodontics

at the USC. He has been published in numerous peer-reviewed journals and textbooks onvarious topics related to Prosthodontics, Aesthetics, and Implant Dentistry. Dr. Reshad iscurrently on the editorial board on various journals including the journal of Aesthetic andRestorative Dentistry. He is an honorary clinical teacher at the Eastman Dental Institute,London University. He maintains private offices in Woodland Hills, California andLondon, England.

Mr. Claudio Tinti was a certified dental technician in 2001 inRome, Italy. From 2001-2008 he was manager for the implantdepartment of Made in Italy Dental Laboratory. From 2008-2013he specialized in complex implant rehabilitation and worked with Mr.Antonello DiFelice, Dr. Gaetaeno Calesini, and Dr. GianfrancoPolitano in Rome, Italy. In 2010, Dieter Schulz on “Bussola Di

Poltz” trained him for dynamic occlusion. Since 2014, he has been a consultant ofBiotech SRL Milling Center Cad/Cam technology related to implant bar design.

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