OVERVIEW OF DENTAL IMPLANTOLOGY

Dr. Deborah M. AjayiConsultant Restorative Dentistry,University college Hospital,Ibadan.

• Implantology is the science of implanting foreign (alloplastic) materials to replace endogenous (lost) organ functions with the objective of tissue-friendly setting (biointegration).

• A Dental Implant is a device inserted into or on the jaw bone to anchor an artificial tooth or denture (prosthesis).

• A root analog.

Mayan civilization first used the earliest known endosseous implant over 1400 years ago.

In 1931, Archaeologists from Honduras confirmed it. In 1950, Researchers at Cambridge University implanted a

chamber of titanium in rabbit’s ear. In 1952, Swedish Orthopaedic Surgeon I-P Branemark

implanted titanium rabbit femur. In 1952, Dr. Leonard Linkow at the New York University

College of Dentistry placed his first dental implant. In 1965, Branemark placed his 1st titanium dental implant. 1960s – Sub-periosteal implants introduced. 1970s– Blade implants was in vogue.

1. Mucosal Insert

2. Endodontic Implant (Stabilizer)

3. Transosseous implant

4. Sub-periosteal implant

5. Endosteal or Endosseous implant

• Endodontic implants are similar to prosthodontic implants in many respects.

• However, they serve another purpose—the stabilization and preservation of remaining natural teeth, not the replacement of lost teeth.

Placed through the mandible (only) Attachments reside

above ridge Rarely used

rests on alveolar ridge, no bone invasion

Less invasive,

less stable

Supports denture

3 types; plate/blade form, ramus frame and the root form-(Most common)

Placed in the bone Single tooth or multiple

teeth replacement Screwed or non screwed Cylindrical or tapered Surface treatment

Grit blasting, plasma sprayed etc

Prof Branemark Root form

implants Improved the

designs & techniques

Reports of success rates from over 15 years experience.

Improved understanding

• A direct structural and functional connection between ordered living bone and the surface of a treated implant, which is visible under the light-optical microscope. (Branemark 1952)

• A time-dependant healing process where by clinically asymptomatic rigid fixation of alloplastic materials is achieved, and maintained, in bone during functional loading. (Zarb & Albrektson,1991)

• Relies on an understanding of– Tissue healing and repair– Tissue remodelling– Effects of force in all vectors– Immune response to the insertion of foreign bodies.

1. Implant biocompatibility2. Implant design3. Implant surface4. Implant bed5. Surgical technique6. Loading condition

Similar soft tissue relationship to natural dentition(sulcular epithelium)

Hemidesmosome like structures connect epithelium to titanium surface

Circumferential and perpendicular connective tissue

No connective tissue insertion No intervening sharpey fiber attachment

Osteoblast is in close proximity to interface Separated from implant by thin amorphous

proteoglycan layer Oxide layer continues to grow- mineral ion

interaction Increase in trabecular pattern Bone deposition and remodeling in

response to stress.

Usually a metal or alloy which must be biocompatible, strong and lightweight.

Most commonly used Commercially pure titanium (CP titanium)

Lightweight, Biocompatible,Corrosion resistant, Strong and low priced

Titanium-aluminum-vanadium alloy (Ti-6Al-4V)- stronger and used with smaller diameter implants

Zirconium Hydroxyapatite (HA), one type of calcium

phosphate ceramic material

ADVANTAGES OF DENTAL IMPLANT DISADVANTAGES OF DENTAL IMPLANT.

• No preparation of adjacent teeth.

• Bone stabilization and maintenance

• Retrievability• Improvement of function• Psychological improvement• May be fixed or removable.• High level of predictability.• It can last for a life time.

• Involves elective surgery.• High operator/technique

dependent.• High initial expense.• Lengthy treatment time.• Requires some moderate

maintenance.• Depends on the availability

of adequate bone quantity and quality.

• Challenging aesthetic

INDICATIONS OF DENTAL IMPLANTS CONTRAINDICATIONS

Good general health Adequate bone quality and

volume Appropriate occlusion and

jaw relations Inability to wear

conventional prosthesis Unfavourable

number/location of abutment

Single tooth loss

• Unrealistic patient expectations• Alcohol/drug dependence and

smoking• Parafunctional habits• Psychological factors• Inadequate ridge/inter-arch

dimensions• Immunosuppression• Diabetes (Uncontrolled)• Coronary artery Disease• Drug therapy: e.g Anticoagulants• Osteoporosis

Replacement of lost tooth teeth due to : Trauma,(Avulsed tooth, fractured tooth,etc) Dental disease (gross caries, endodontic failures,

periodontitis etc) or developmental abnormalities(congenitally missing

tooth,). To overcome problems of free end saddle Anchorage for orthodontic tooth Single tooth replacement Fixed multiple tooth loss- Implant

retained bridge prosthesis Completely edentulous patients – implant

retained removable dentures.

Patient Education. Treatment options Multidisciplinary approach. Long-term commitment Surgical and Restorative procedures Maintenance and regular recall

Fee and payment policy The inform consent.

General Health : • History : Dental, Medical, Social and Habit• Examination ; • Laboratory investigations

Predictable risks

Teeth Periodontium Radiographic analysis Surgical analysis Aesthetic analysis Occlusal analysis

• Number and existing condition:– Minimum 6-7mm between teeth to facilitate

implant placement– >1.5mm between implant and natural teeth– 7mm from centre of implant to centre of

implant for edentulous– More than 10mm mesiodistal space- single

tooth implant not recommended• Prognosis of remaining teeth• Tooth and root angulations and proximity• Mesiodistal width of the edentulous space

According to Lekholm and Zarb.,1985 classified bone quality as:

Type I Composed of homogenous compact bone, usually found in the

anterior mandible Type II A thick layer of cortical bone surrounding dense trabecular bone,

usually found in the posterior mandible Quality III A thin layer of cortical bone surrounding dense trabecular bone,

normally found in the anterior maxilla but can also  be seen in the posterior mandible and the posterior maxilla.

Quality IV A very thin layer of cortical bone surrounding a core of low-density

trabecular bone, It is very soft bone and normally found in the posterior maxilla. It can also be seen in the anterior maxilla.

6mm or below buccal-lingual width with sufficient tissue volume.

8mm interradicular bone width 10mm alveolar bone above IAN canal

or below maxillary sinus

There is need for sufficient tissue volume to create gingival papilla

Need some attached gingiva to maintain peri-implant sulcus

The implant is placed 2-3mm apical to free gingival margin of adjacent tooth/teeth.

Radiographs : periapical, occlusal, panoramic and CT scan or tomograph as indicated.

CT gives more accurate and reliable assessment of bone

Assess Periapical pathology Adequate vertical bone height Adequate space above IAN or below the maxillary

sinus Adequate interradicular area Bone quality and quantity

Smile line Lip shape Existing ridge Restored implant

should appear to emerge from the gingiva

Produce a natural and desirable appearance

Assess for parafunctional habit: tooth lost to occlusal

trauma or parafunctional habit is less successful with implant

Diagnostic cast is produced and mounted to determine opposing occlusion

Implant surgery Single stage Two stages

Placement of Implant Immediate Standard Delayed

Implant loading Immediate Delayed

• Pre-operative medication• Local Anaesthetic with or without general

sedation• Analgesics, such as ibuprofen or

paracetamol can be administered immediately prior to surgery.

• Sterile environment should be maintained throughout the surgery.

• Chlorhexidine 0.2% is used as a pre-operative mouthwash and skin preparation.

A mid-crestal incision with vertical relieving incisions (if closed to adjacent teeth including inter-dental papilla).

A mucoperiosteal flap is raised.

The flaps should be elevated sufficiently far apically to reveal any bone concavities, especially at sites where perforation might occur.

EDENTULOUS JAW FOR IMPLANT MARKINGS FOR INCISION

MID CRESTAL INCISION MUCOPERIOSTEAL FLAP

• It is essential not to allow the bone to be heated above 47°C during preparation of the site as this will cause bone cell death and prevent osseointegration.

• This problem may be avoided by: – Using sharp drills – Incremental drilling procedure with increasing diameter drills – Avoidance of excessive speed– Using copious sterile normal saline irrigation.

Preparation commence with Initial penetration.

Pilot drill

guide pin is placed to check the direction

Check the final depth with a depth gauge

Check the spacing and angulation of the implant sites carefully with direction indicators throughout the drilling sequence

Angulations of the implants should be

consistent with the design of the restorations

Implant should be placed such that; – It is within bone along its entire length.– It does not damage adjacent structures such as

teeth, nerves, nasal or sinus cavities. • Multiple implants sholud be placed in fairly

parallel arrangement.

• The top of implant should be placed sufficiently under the mucosa to allow a good emergence profile( eg 2-3mm apical to labial CEJ of adj. Teeth)

Buccal plate surface 0.5 mm.

Lingual plate surface 1.0mm

Maxillary sinus 1.0mm

Incisive canal avoid midline of maxillaNasal cavity 1.0mm

Inferior alveolar canal 2. 0 mm. From superior aspect of the canal

Mental nerve 5. 0 mm from anterior of the bony foramen.

Adjacent natural tooth 0.5 mmBetween 2 implants 3.0 mm

• The implant is supplied in a sterile container, either already mounted on a special adapter or unmounted necessitating the use of an adapter from the implant surgical kit.

• In either case the implant should not touch anything before its delivery to the prepared bone site.

• Cylindrical implants are either pushed or gently knocked into place.

• Screw shaped implants are either self tapped into the prepared site or inserted following tapping of the bone with a screw tap.

• The mucoperiosteal flaps are carefully closed with multiple sutures either to bury the implant completely or around the neck of the implant in non-submerged systems.

• Silk sutures are satisfactory and others such resorbables are good alternatives.

Take Postoperative radiographs(Periapicals) to evaluate implant position in relation to adjacent structures.

Also for monitoring the ossteointegration.

Haemostasis Medications

Dalacin C 300mg 12hourly for 5 days Tab vitamin C 1g daily for 2weeks IM Paracetamol 600mg stat Tabs Diclofenac 50mg 12hourly for 3days

Ice packs to reduce swelling and pain chlorhexidine 0.2% mouthwash Avoid smoking and alcohol.

Intra operative: Tear of flap. Insufficient irrigation thermal injury to

bone. Perforation of buccal or lingual cortex Impingement on inferior dent canal/ nerve. Impingement on adjacent tooth. Perforation of maxillary sinus, Lack of primary stability. Fracture of implant.

Immediate post-op: Pain ( rare) Haemorrhage( also rare) Swelling Nerve injuries.

Delayed: Infection Secondary Haemorrhage. Nerve injury. Loosening of implant & Loss of implant

Anatomical Neurological Deintegration Progressive thread exposure Gingivitis Hyperplastic tissue Fractured Implant

Exposure of implant with minimal flap reflection.

Removal of the cover screw.

2) Custom fabricated Abutment 3) CAD/CAM fabricated

Wax up of the superstructure

Fabricate the framework

Venering(porcelain baking)

The completed, metal-ceramic superstructures

• According to Harvard success Criteria for Dental implant, Dental implant must provide functional service for 5 years in 75% of cases.

• Criteria are both subjective and objective. Subjective Criteria• Adequate function• Absence of discomfort• Improved aesthetics• Improved emotional and psychological

wellbeing

• Bone loss no longer than 33% of vertical length of implant

• No peri-implantitis• No associated radiographic radiolucency• Marginal bone loss 1.0-1.5mm first year; then <

0.1mm annually thereafter• Good occlusal balance and vertical dimension• Gingival inflammation amendable to Rx• Mobility of less than 1mm in all direction• Absence of symptoms of infection• Absence of damage to surrounding structure• Healthy connective tissues

Primary goal is to protect and maintain “tissue-integration”;good oral hygiene is a key element!

Implant patients should be thoroughly instructed in maintenance therapy with the understanding that the patient serves as co-therapist

Home-care regimen periodic recalls reinforcing regimen strict adherence to recall schedule & verification of function, comfort, and

aesthetics. immediate post-delivery 24 hours one week one month 6 months bi-annual or annual evaluation

lifetime maintenance commitment

Dental implant is one of the defining advances in clinical Dentistry.

Therefore every Dentist should key into the current trend in implantology and use such to improved the patient well being and psychosocial life of patients.

Thank you for your attention.

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