CHAPTER 14: IMPLANT TREATMENT

ppt only!!

Dental implant

a permucosal device that is compatible and biofunctional and is placed on or within the bone to provide support for prosthesis

structure of dental implant

Bone-implant Interface

Fibro-osseous integration

Osseointegration

Bioactive integration

Fibro-osseous integration

• Is defined as “tissue to implant contact by interposition of a healthy dense collagenous tissue between the implant and the bone interface”.

• Attributed to proliferation of connective tissue into the interface.

• Not desirable since union is WEAK.

Bioactive integration

Is defined as the integration which results by a physiochemical interaction between collagen of bone and hydroxyapatite crystals of the implants.

Osseointegration

• Is defined as a direct structural and functional connection between ordered living bone and the surface of the load carrying the implant

• Growth of bone in direct contact with implant surface without an intervening band of organized connective tissue

Four Factors for Osseointegration to Occur

A biocompatible material

Atraumatic surgery

implant immobility, relative to bone, during healing phase

Implant placement in intimate contact with bone

A biocompatible material

Material of choice = titanium (biologically inert)

Atraumatic surgery

• Handpiece = slow speed with high torque

• Provide copious irrigation

• Bone temperatures below 47°C

implant immobility, relative to bone, during healing phase

• If primary stability may be less = two-stage surgery

• If primary stability is adequate = single-stage surgery

Implant placement in intimate contact with bone

Implant should engage two cortical plates of bone

• Utilize a long, wide-diameter implant

Classification of Implants (based on shape and form)

Endosteal/Endosseous

Subperiosteal

Transosteal/Mandibular staple

Endosteal/Endosseous

Is surgically placed into the bone

• Shaped like a small screw, cylinder or blade

• The most popular implant

Subperiosteal

Is surgically placed under the periosteum and rests on the bone

• Located on or above the bone

• Most common in the mandible

Transosteal/Mandibular staple

Consists of a horizontal beam attached to metal rods and inserted all the way through the mandible from superior border to the inferior border

• Seldom used due to its highly invasive nature

• Most commonly used to support
a mandibular denture with severe resorption

Factors affecting the load-bearing

Factors affecting the load-bearing capacity of implants

Number and size of the implants

Arrangement and angulation of the implants

Volume and quality of the bone-implant interface

Number and size of the implants

For completely edentulous arch: 4 implants for MN; 6 implants for MX

Connecting a single implant to one natural tooth with a fixed partial denture should be avoided.

For three-tooth edentulous span
a. 3 implants with 3 splinted crowns
b. 3 implants with 3 single-unit crowns c. 2 implants as terminal abutments for

a 3-unit fpd
d. 2 adjacent implants with a fpd with a

cantilevered pontic

Arrangement and angulation of the implants

(loads directed through the long axis of the implants)

Volume and quality of the bone-implant interface

(bone density)

Classification of Bone Quality / Density

Type I bone

Type II bone

Type III bone

Type IV bone

Type I bone

Composed of homogenous compact bone, less blood supply than the rest of the types, takes 5 months to integrate

Type II bone

Composed of a thick layer of compact bone surrounded by a core of dense cancellous or trabecular bone, takes 3-4 months to integrate

Type III bone

Composed of a thin layer of cortical bone surrounded by a core of dense trabecular bone, takes 6 months to integrate

Type IV bone

Composed of a thin layer of cortical bone surrounded by a core of low density trabecular bone of poor strength, requires the longest time to integrate – 8 months

Surgical Procedures: Endosseous Implant

One-stage / Non-submerged

Two-stage / Submerged

One-stage / Non-submerged

In this procedure, the coronal portion stays exposed through the gingiva during the healing period

• The healing abutment protrudes about 1-2mm from the crest of bone and flaps are adapted around the implant

Two-stage / Submerged

The 1st stage ends by suturing the soft tissues over the implant so that it remains excluded from the oral cavity

• Implants are left undisturbed for 2-3 months in the mandible and 4-6 months in the maxilla

• In the 2nd stage, the implant is uncovered and titanium abutment is connected to the implant body

Implant Procedures

Local anesthesia (local infiltration or nerve block)

Implant site exposure (flapless surgery or with tissue elevation)

Flap reflection

Implant insertion

Suturing

Implant Site Exposure for Flapless surgery (no flap)

Done when there is adequate keratinized tissue over an ideal ridge form

• Advantages: creates least soft tissue trauma and provides best postop esthetics

• Example: use of tissue punch

Implant Site Exposure for With tissue elevation (with flap)

Advantages are:
convenient retraction, better access and visualization; additional procedures such as bone grafting can be done

• Example: midcrestal incision (mesial-distal surfaces of the teeth adj to the edentulous space)

Preparing the Osteotomy

Drilling is done in series of steps.
• All drills, except the last drill, should be irrigated.

Establish the length before the width

steps:

Step 1. Initial osteotomy

Often a pilot drill is used to create an initial hole in the bone.

2. Deepen the osteotomy

Larger drills are used to increase the length

3. Assess parallelism

Position parallel pins. Take radiograph.

4. Enlarge the osteotomy

Widen the osteotomy up to the desired diameter.

5. Place the implant fixture

Lower rpm with no irrigation to promote bleeding.

Implant Components

Implant Body or Fixture

Cover or Healing Screw

Healing or Interim Abutment

Impression Coping

Implant Analog or Replica

Implant Abutment

Implant Body or Fixture

is the implant component placed within bone

Cover or Healing Screw

a small screw placed over a dental implant to protect it during the healing phase (two-stage) before suturing

• purpose: to prevent bone from growing between the screw and the implant

• in the second stage of two- stage surgery, the cover screw is removed and replaced with a healing abutment

Healing or Interim Abutment

are dome-shaped intraimplant screws that provide permucosal access to the implant platform

• are placed immediately after a one-stage surgical approach or after uncovering in a two- stage surgical approach

• should project 1 to 2 mm superior to the height of the gingival tissue

Implant Abutment

the abutment is the portion of the implant that supports or retains a prosthesis or implant superstructure.

• three main categories:
(1) screw retained
(2) cement retained
(3) prefabricated attachment abutments

Impression Coping

aka: impression posts, impression pins or implant transfers

facilitates transfer of the intraoral location of the implant to the same position on the laboratory cast

• the impression transfer can be closed-tray transfer or open-tray transfer

[listen record on this part, & see ppt again]

Implant Analogues (laboratory analogues)

are screwed directly into the impression coping to replicate exactly the top of the implant fixture in the laboratory cast

• this allows laboratory technician to have an accurate and flexible representation of soft tissue

[listen record on this part, & see ppt again]

Impression Techniques

Open-tray technique (pick-up or direct method)

Closed-tray technique (transfer or indirect method)

Open-tray technique

aka: pick-up or direct method

involves using a special impression tray with openings that allow the impression copings to protrude.

• The clinician unscrews the

impression copings after

the impression material

has set, capturing the

exact position of the implants.

Closed-tray technique

aka: transfer or indirect method

involves using standard impression trays and transferring impression copings after the impression has set.

• The clinician removes the

impression and then

unscrews the copings,

placing them back into the

impression before sending it to the dental lab.

1mm

Minimum required distance between implant and Buccal plate,
Lingual plate, nasal cavity, maxillary sinus

1.5mm

Minimum required distance between implant and Adjacent natural tooth

2mm from superior bony canal

Minimum required distance between implant and inferior alveolar canal

3mm between outer edge of implants

Minimum required distance between implant and Inter-implant distance

5mm from anterior foramen

Minimum required distance between implant and Mental nerve

Avoid midline maxilla

Minimum required distance between implant and Incisive nerve

see photo for the explained answer

If a 4-mm-diameter implant is planned to replace a missing tooth, how much total

mesiodistal width is required?

If two adjacent 4-mm implants?

Contraindications for Implants

medical conditions (diabetes, osteoporosis, HIV, AIDS, uncontrolled metabolic diseases)

medications (bisphosphonates, anti-angiogenics)

medical treatments (chemotherapy and irradiation)

psychological or mental conditions (psychiatric syndromes (e.g., schizophrenia, paranoia) or mental instabilities (e.g., neurosis, somatic symptom disorder)

certain habits or behavioral considerations such as smoking, tobacco use, substance abuse, and parafunctional habits

Types of Peri-implant Diseases

Peri-implant mucositis

Peri-implantitis

Peri-implant mucositis

Inflammation confined to soft tissue surrounding an implant

Peri-implantitis

Peri-implant bone loss in conjunction with soft tissue inflammation

Early implant Failure (before ossseointegration)

• Improper preparation of the implant site

• Bacterial contamination

• Improper mechanical

  stability following implant

  insertion
  • Premature loading of the

  implant

late implant Failure (before ossseointegration)

Excessive load
• Infection, e.g. peri-implant

mucositis, peri-implantitis