In The Name Of God

Presented by:Dr.Ali BeygiSupervised by: Dr. Mansour Rismanchian And Dr.saied Nosouhian Dental of implantology Dental implants research centerIsfahan university of mediacal science 

DIAGNOSTIC CASTS AND SURGICAL TEMPLATES

Once the preimplant phase is satisfactory, prosthetically driven implant placement also must accommodate anatomical limitations, and possibleadaptations of the original planning may be necessary .

This set of requirements can he achieved using precise surgical guides

DIAGNOSTIC CASTS

DIAGNOSTIC CASTS

The dentist selects before surgery

1. the final prosthesis2. the number and location of ideal optional abutment sites 3. the occlusal schemes

DIAGNOSTIC CASTS

• permit an open discussion of treatment with other practitioners and laboratory technicians

• assist with implant site selection and angulation requirements during the surgical phase by Surgical templates

• may be used for presentations to motivate the patient's acceptance of the proposed treatment

Diagnostic casts mounted using an accurate recordof centric jaw relationship and maxillomandibularocclusion on a semiadjustable articulator provide muchinformation related to treatment that influences thefinal prosthodontic treatment plan. Important factorsinclude the following:

1. Occlusal centric relation position, including premature occlusal contacts2. Edentulous ridge relationships to adjacent teeth and opposing arches3. Position of potential natural abutments, including inclination, rotation, extrusion, spacing, parallelism, and esthetic considerations4. Tooth morphology, structure of potential abutments, and overall conditions (e.g., wear facets, fractures)

5. Direction of forces in future implant sites6. Present occlusal scheme, including the presence of balancing or working contacts7. Edentulous soft tissue angulation, length, width, locations, permucosal esthetic position, muscle attachments, and tuberosities8. Interarch space9. Overall occlusal curve of Wilson and curve of Spee10. Arch relationships11. Opposing dentition12. Potential future occlusal schemes13. Number of missing teeth14. Arch location of future abutments15. Arch form and asymmetry

DIAGNOSTIC CASTS

Partially edentulous patients often present occlusal interferences as a result of tooth migration

The dentist identifies and eliminates deflective contacts beforethe implant prosthodontic phase:

A face-bow transfer and centric and eccentric occlusal records should help mount the casts on a semiadjustable articulator (Figs. 13-2 to 13-5)

Diagnostic casts should be mounted with an openbite registration in centric relation

Face bow mounting

Kois Dento-Facial Analyzer System, Panadent

Kois has developed a unique facebow transfer thatcorresponds to the facial midline and horizontal plane to the 100-mm distance of the conditional hinge position.

This technique simplifies the process of the facebow transfer and ensures the occlusal plane of the teeth is evaluated and fabricated correctly

A considerable prosthetic advantage is present when centric relation occlusion is harmonious with centric relation.

• permits a closed-mouth centric recording during prosthetic reconstruction for the fabrication of the prosthesis

• without the need for an accurate hinge axis recording of the condyles or fully adjustable articulators

When incisal edge position of the maxillais determined, its position usually causes a steeperprotrusive or excursive position than the condylardisk assembly. As a result, posterior disocclusion canbe established easily. These conditions permit thereconstruction to be fabricated in the laboratory andtransferred accurately to the patient.

Both arches may require prosthodontic treatment to establish the desired occlusal schemes.

a need to increase the anterior guidance

for posterior disclusion in excursions

warrants bilateral balance occlusion

DIAGNOSTIC CASTS

Diagnostic casts also may be mounted on anarticulator for selective alterations and prewaxing

The specific laboratory communication• Occlusion• Esthetics• Edentulous ridge in relation to implant placement

provide a guide for provisional restorations

DIAGNOSTIC CASTS

The dentist, in addition to using radiographic surveys,may also use the diagnostic casts to estimate theunderlying bone volume.

The dentist inserts a needle equipped with an endodontic stop through the patient's mucosa overlying the implant site

• measures the mucosal thickness on the crest, facial, and lingual areas

Or use a bone caliper• bone width can be measured by the calibrated instrument

The edentulous region of the diagnostic cast is cut perpendicular to the ridge

Cross section then is shaded with a pencil to represent the tissue thickness observed while probing

RESTORATIVE DIAGNOSIS VERSUS SURGICAL DIAGNOSIS

Although a prosthetically driven implant placement is best for: • simplification of abutment selection• ideal force distribution• long-term success

Anatomical limitations may force the surgeon to redirect the implant angulation

the prosthetic requirement cannot be met surgically

buccal bone loss o modification of the treatment plan and placement of a bone graft lingual concavity o a change in angulations or implant selection is the only option

If a concavity is suspected, further radiographs such as a traditional tomogram or a computed tomography scan, together with a diagnostic radiographic template, will reveal the angulation dilemma and allow for clear communication between the restorative dentist and the surgeon

the mandibular nerve is relatively high Therefore the dentist must make a decision to modify the angulation and later redirect the implant path with an angulated abutment, position a shorter implant, or avoid this site all together

SURGICAL GUIDES

The restoring dentist fabricates the surgical guide template after the presurgical restorative appointments

surgical template dictates to the surgeon the implant body

placement that off ers the best combination of :

(1)support for the repetitive forces of occlusion (2)esthetics (3)hygiene requirements

SURGICAL GUIDES

should be stable and rigid when in correct position

should relate the ideal angulation for implant insertion on the diagnostic wax-up,during surgery

This requires at least two reference points for each implant(respectively on the occlusal surface (central fossa or incisal edge) of the planned abutment crown and the crest of the ridge represents about 8 mm) joined by a line that represents the path of ideal implant insertion

SURGICAL GUIDES

The ideal angulation is: perpendicular to the occlusal plane and parallel to the most anterior abutment (natural or implant) joined to the implant.

should not be bulky and diffi cult to insert or obscure surrounding surgical landmarks

must not contaminate a surgical field during bone grafts or implant placement

should be transparent and allow easy access for the surgeon and the assistant

(what side of the arch is operated on, where the surgeon and assistant will be seated,and whether the surgeon is right- or left-handed)

SURGICAL GUIDES

should relate the ideal facial contour

o can determine the amount of augmentation required for implant placement or support of the lips and face

template may be used for a bone graft later the same template may be used for insertion of implants and again for implant uncovery

SURGICAL GUIDES

To construct a surgical guide, modification of the radiographic guide is often possible

With ideal wax-up when the long axis of the teeth is visible and can be maintained,after verifying bone availability, then enlargement of the longaxis channel guarantees accurate implant guidance.

SURGICAL GUIDES

Diagnostic wax-upo No selective grinding or modification is performed on

any teeth that have not been altered before surgery; otherwise, the template will not fit correctly

irreversible, hydrocolloid impression is made of the diagnostic wax-up and poured in dental stone

a vacuum acrylic shell (0.060 to 0.080 inch) is pressed Trim• To indicate the teeth position and the lingual contour

in the posterior regions and facial contour in the anterior region.

• If no natural teeth remain, the posterior portion of the template should be maintained and cover the retromolar pads or tuberosities and palate to aid in positioning.

Use a modification of Preston's clear splint

This provides maximum freedom for implant placement yetcommunicates the ideal tooth position and angulation duringsurgery.A surgical guide template with 2-mm holes through theocclusal surface of a denture tooth is too limiting for thesurgeon, although it identifies precisely the ideal implantplacement

A soft linero Tuberosity or retromolar pad regions and other soft

tissue areas not involved in surgery The acrylic resino over the occlusal portion of the template where no implants are planned

The patient then occludes into this index

The template can be correctly positioned over the edentulous ridge during surgery once the tissue is reflected.

In the edentulous arch the vacuum form may be fabricted from the existing removable prosthesis

A full wax-up of the missing teeth • A hole is prepared through the middle of the central

fossa of each future posterior abutment and the incisal edge position of anterior teeth

On the stone model, each site chosen should be drilled

• To a depth corresponding to the approximate soft tissue thickness measured on a panoramic radiograph (usually about 2 to 3 mm)

An orthodontic wire is passed through the teeth and into the holes

A small loop is made at the other end of the wire to create a retention form

Each pin must be embedded fully in the acrylic at the proper centric and vertical relationships

A surgical template for the complete edentulous arch also may engage the occlusal aspect of the opposing teeth

Once the soft tissue is reflected

The surgical guide easily determines the implant position and angulation, yet the surgeon can have the patient open and drill into the bone with complete access and vision

also may he used with a panoramic radiograph before surgery to determine vertical magnification or horizontal distortion

at Stage II uncovery to find the position of each implant ---FP1

A surgical template for the complete edentulous arch also may engage the occlusal aspect of the opposing teeth

FP1 , FP2 :

straight abutment directly under the incisal edge of the final crown for a cemented prosthesis

For screw-retained prostheses, the implant should emerge toward the cingulum

FP3 :

the mesiodistal position of implant abutments may be placed without regard to the actual position of the crowns

SURGICAL GUIDES

An implant placed adjacent to a natural tooth

In esthetic regions

1.5 to 2 mm away from the crown , where the contour of the interdental papilla is a determining factor

In unesthetic regions

implant placed at least 1.5 mm away from an adjacent tooth ,minimizes the risk of surgical error and provides easier access for hygiene

SURGICAL GUIDES

The treatment plan for an implant in the maxillary firstpremolar position must reflect careful consideration for theangulation of a natural canine when present implant should be

angled to follow theroot of the canine

ADVANCED SURGICAL GUIDANCE

ADVANCED SURGICAL GUIDANCE

• Advanced surgical guides require computed tomography (CT) scanning as a prerequisite for analysis

• These guides also necessitate a software-supported rendering to improve planning by using three-dimensional (3D) visualization.(as demonstrated by Jacobs et al.who reported that dentists using two-dimensional (2D)cross sections make numerous modifications duringthe surgical phase of treatment, whereas the additionof a 3D representation improves thecorrelation between planned and actual placement)

• software rendering that includes CT data and implant planning can be exported later to a computer-aided design (CAD) software

Surgical guidance can be classified in two categories

use of computer-aidedmanufacturing of guides

using virtual planning of implant positions.

Guides are delivered to surgeon before the procedure

no modifi cation is possible

during surgery

use of navigation techniques

There is no guidance of the drill, but

software provides real-time feedback to the surgeon in order to compare execution with planning

SURGICAL GUIDES

Computer-Assisted Design and Manufacturing of Surgical Guides

Computer-Assisted Design and Manufacturing of Surgical Guides

Drilling of guides

Stereolithography

Computer-Assisted Design and Manufacturing of Surgical Guides

Stereolithography

• layer of liquid polymer is deposited and cured by a computerdriven laser. Additional layers or sections are stacked and polymerized until a final model is generated

• the data source is a CT

Computer-Assisted Design and Manufacturing of Surgical Guides

Stereolithography

• CT files and dentist's plan is used to design the guides

• Software programs are capable of maximizing stability and implant retention by detecting the best insertion path while avoiding undercuts within the bone

• irrigation holes,• sufficient surface areas

while performing osteotomies,

• buccal extensions if a transversal retention screw is desired

• Serial templates-drill diameter

Computer-Assisted Design and Manufacturing of Surgical Guides

Stereolithography

• Once designs are completed, the guides are processed with the stereolithographic method

• stainless steel tubes are later pressed into place

Computer-Assisted Design and Manufacturing of Surgical Guides

• The method necessitates the incorporation of metal markers at specific locations in the scannographic guide that therefore must be provided by the manufacturer

• Once returned and used during CT scanning, the dentist creates a surgical plan using a software

Drilling of guides

The dentist then returns the plan, model, and scannographic template for conversion of the template into the surgical guide

Computer-Assisted Design and Manufacturing of Surgical Guides

• the model is set onto a computer-controlled milling machine, which matches the fiducial landmarks to their CT-scanned images

• computer-driven drill press • Metal guide sleeves then are added

Drilling of guides

Because of the ability of the guide to rest on natural teeth, this method can be applied to small edentulous spans

Surgical Navigation

Surgical Navigation

IGI

• CT SCAN in the presence of the scannographic template attached to a manufactured arch registration device

• CT transferred to a custom software virual implant planning

• Before surgery registration device is repositioned matching process

• During surgery reference body to locate patient jaw and diod-equipped handpiece to locate the surgeon,s movement

Surgical Navigation

VirtualScop

• Elimination of positioning markers during CT scanning

This system offers a real-time three-dimensional capture of the arch via an ultrasound probe.This Mapping of the clinical image can be matched to the CT-scanned data and updated continuously

the actual drill position are viewed at alltimes through glasses worn by the

surgeon

THANKS FOR YOUR ATTENTION

Ali Beygi