Dental Implant (In-Depth)

Topics

What is dental implant?

Composition of an Implant

Anatomy of Implant

Who should perform the Implant placement?

Surgical procedure

Restoration Procedure

What is dental implant?

Dental implant is an artificial root of the tooth used in dentistry to support restorations that resemble a tooth or group of teeth.

All dental implants today (21st century) are root-form and they are placed inside the bone (endosseous implant). Prior to the advent of root-form endosseous implants, most implants were either blade endosseous implants, in that the shape of the metal piece placed within the bone resembled a flat blade, or subperiosteal implants, in which a framework was constructed

Implant is used to support a crown (for the case of missing a single tooth) or they can be used to support bridge or denture (for the case of multiple missing teeth) that are designed to look just like your natural teeth.

  • Dental implants are small screws made of pure titanium that are surgically implanted in your jaw.
  • They provide a permanent foundation for crowns, bridges and dentures.
  • They are proven technology backed up by more than 50 years of development.
  • Dental implants protect your jaw against bone loss.
  • Because dental implants anchor in the jawbone just like natural teeth, they are the best choice for natural-looking tooth replacement

Composition of an Implant

A typical implant consists of a titanium screw (resembling a tooth root) with a roughened or smooth surface. The majority of dental implants are made out of commercially pure titanium, which is available in 4 grades depending upon the amount of carbon and iron contained. More recently grade 5 titanium has increased in use which offers better tensile strength and fracture resistance.  Implant surfaces may be modified by plasma spraying, anodizing, etching or sandblasting to increase the surface area and the integration potential of the implant.

Anatomy of Implant

Implant/Fixture – titanium material for osteo-integration with the surrounding bone.
Abutment – structure which connects the implant to the crown and it is situated in the gum area.
Crown – Usually porcelain fused to metal material that can be seen in the mouth.

What is the difference between dental implant and natural tooth?

Who should perform the Implant placement?

Implant surgery may be performed as an outpatient under general anesthesia, oral conscious sedation, nitrous oxide sedation, intravenous sedation or under local anesthesia by trained and certified clinicians including general dentists, oral & maxillofacial surgeons, prosthodontists, and periodontists.

Surgical procedure

Surgical planning

Prior to commencement of surgery, careful and detailed planning is required. Two-dimensional radiographs, such as orthopantomographs (OPG) or periapicals radiograph are often taken prior to the surgery. They are used to identify vital structures (such as the inferior alveolar nerve or the sinus), as well as the shape and dimensions of the bone to properly orient the implants for the most predictable outcome. In some instances, a Cone beam tomogram (CBT) or CT scan will also be obtained.

Jaw X-ray — Dental Panaromic Tomogram (or OPG)
Cone Beam Images of the jaw bone

Implant placement procedure

In its most basic form the placement of an osseointegrated implant requires a preparation into the bone using either hand osteotomes or precision drills with highly regulated speed to prevent burning or pressure necrosis of the bone. After a variable amount of time to allow the bone to grow on to the surface of the implant (osseointegration) a tooth or teeth can be placed on the implant. The amount of time required to place an implant will vary depending on the experience of the surgeon, quality and quantity of the bone and the difficulty of the individual situation (usually between 30 minutes and 2 hours).

Preparation of recipient bone for implant insertion

Surgical procedure

An incision is made over the crest (highest point of the gum ridge) of the site where the implant is to be placed. The gum (which is referred to as a ‘flap’) was raised  to exposed the recipient bone. Then, a pilot hole is bored into the bone, taking care to avoid the vital structures. Drilling into jawbone usually occurs in several separate steps. The pilot hole is expanded by using progressively wider drills (typically between three and seven successive drilling steps, depending on implant width and length). Care is taken not to damage the bone cells by overheating. A cooling saline or water spray keeps the temperature of the bone to below 47 degrees Celsius.

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Implant insertion into recipient bone

The implant screw can be self-tapping, and is screwed into place at a precise torque so as not to overload the surrounding bone (overloaded bone can die, a condition called osteonecrosis, which may lead to failure of the implant to fully integrate or bond with the jawbone). Typically in most implant systems, the osteotomy or drilled hole is about 1mm deeper than the implant being placed, due to the shape of the drill tip. Surgeons must take the added length into consideration when drilling in the vicinity of vital structures.

Before implant insertion
After implant insertion on the upper right area

For Anxiety Patient…

If in a case of an anxious patient come for implant placement, usually, we will prescribe some medication of reduce anxiety before the surgery or patient will have to inhale nitrous oxide during the procedure so that he/she will feel relax and calm all the time during surgery. If the patient is extremely phobia of surgery, then he can opt for surgery done under general anaesthesia which required hospitalization.

Healing time

Practitioners usually allow 2–6 months for healing. If the implant is loaded too soon, it is possible that the implant may move which results in failure. The subsequent time to heal, possibly graft and eventually place a new implant may take up to eighteen months. For this reason many are reluctant to push the envelope for healing.

Wound healing – immediate after surgery
Wound healing – 7 days after surgery

One-stage or two-stage surgery?

When an implant is placed with a ‘healing abutment’, which comes through the mucosa (or the gum), it is referred as the one-stage surgery. (Picture above is one-stage surgery where the healing abutment – green and purple screw can be seen on the gum surface)

When an implant is placed with  a ‘cover screw’ which is flush with the surface of the dental implant and usually hidden under with the gum, this surgery is referred as the two-stage surgery. A second surgery is needed 3 months later to exposed the cover screw and the cover-screw is to be placed with healing abutment.

Two-stage surgery is sometimes chosen when a concurrent bone graft is placed or surgery on the mucosa may be required for esthetic reasons. Some implants are one piece so that no healing abutment is required.
In carefully selected cases patients can be implanted and restored in a single surgery, in a procedure labeled as “Immediate Placement“. In such cases a provisional prosthetic tooth or crown is shaped to avoid the force of the bite transferring to the implant while it integrates with the bone.

Surgical timing

There are different approaches to place dental implants after tooth extraction. The approaches are:

  • Immediate post-extraction implant placement.
  • Delayed immediate post-extraction implant placement (2 weeks to 3 months after extraction).
  • Late implantation (3 months or more after tooth extraction).

Restoration Procedure

For missing single tooth

Implants can be made to replace missing tooth or teeth. If an implant is used to replace one missing tooth, it is  implant-supported crown.

Implant-supported crown is used to replaced a missing tooth

Multiple missing tooth

Implant-supported crown can be used to replaced multiple missing tooth. Every missing teeth will be replace with implants

Implant-supported crown

If in cases where the bone is too narrow and not suitable for implant placement then implant-supported bridge will be used to avoid those unsuitable area.

Implant supported bridge

Implant-supported bridge also can be used to reduce implant cost and surgical time!!

Impression taking

After the implant in well osteo-integrated with the surrounding bone, construction of the outer part — the crown/tooth procedure can be started. Usually it started with impression taking after the gum heals around the healing abutment.

Gum healing after a week with healing abutment in two-stage surgery

Impression is used to make a duplication of the gum and the implant position where the laboratory technician can fabricate crown/bridge outside patient’s mouth.

The impression transfer posts are inserted on the implant fixtures
And impression of the gum and implant are taken with silicone material

Crown/Bridge fabrication

In the dental laboratory, porcelain fused to metal crowns or bridges are fabricated. Usually it takes about 2-3weeks to be done.

A model with implant is made from the silicone impression.
On the model, crowns are fabricated and ready to be fit in patient mouth!!
Another case with two implant-supported bridges

Restoration of crown/bridge in the mouth

There are basically 2 types of ways by which the crowns/bridges that can be attached to the implant:

Screwed retained – The crowns/bridges are retained in the mouth with screw that screw into the abutment. The advantage of using this way is easy to be removed when ever need (eg. if the crown break or the abutment become loosen). However, the aesthetic will be compromised. Usually screwed retained method is used in posterior region where aesthetic is not an issue or in straight abutment type.

Cemented retained – The crowns/bridges are cemented onto the abutment with cement such as temp-bond, GIC etc. The advantages is very good aesthetic. Usually used in the anterior region or in angle abutment type.

Below are the procedures of installing the final restoration of a screw-retained type:

After removing the healing abutment, the implant ‘hole’ will be assessed
The abutments are screwed into the implants with force 15Ncm

Then, the crowns are fit onto the abutments and the colour, shape and occlusion will be assessed
After that,  crowns will be screw onto the abutments with force of 15Ncm
The hole at the palatal surface will be covered with filling material
Final result!!

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Problems with missing teeth

General-Dentistry

Topics

  • Problems with missing tooth/teeth
  • Treatment Options for Replacing Missing Tooth/Teeth

Problems with missing tooth/teeth

As soon as a tooth is being removed, we have to think of the options available for replacing that missing tooth. Most of us don’t really know the consequences or future problems that are going to be faced by us resulting from tooth extraction.

These are some of them:

1. Chewing efficiency decrease

The most common problem patient face immediately after extraction it lost of chewing efficiency. He will tends to chew more on the opposite side. If the extraction involved multiple teeth, then patient will have to switch to soft diet which might result in poor digestion and malnourished. Therefore replacement of missing teeth is crucial to regain back patient’s normal chewing.

2. Over eruption of opposite tooth

Over-eruption of upper molar tooth

Commonly happen after extraction of the lower molar causing the upper molar to erupt further downwards. This will result in food stagnant in the interproximal (in-between of the teeth) area making the teeth easily develop dental caries.

3. Migration of neighbour tooth

The neighbour teeth will migrate to the extraction site as soon as the tooth was remove. Usually, the patient will begin to notice it after a year or more. In some delayed cases, tooth extraction causes the front teeth to have multiple gaping which resulted in poor aesthetic. Both migration and supra-eruption of teeth will make restoration or replacement of the missing tooth difficult.

4. Bone lost

The gum become narrow due to bone loss after extraction

Alveolar bone lost significantly after missing teeth. As the result, the upper lip looks flatten due to lost of support from the anterior alveolus bone. Lost of bone also makes implant insertion difficult which might required bone harvesting before implant insertion.

5. Attrition of the remaining teeth

When patient loose most of his back teeth, he will try to use his front teeth to grind food and eventually all the front teeth will look much shorter due to attrition from chewing. Attrition also will make the teeth become sensitive to cold and sweet (dentinal hypersensitivity).

6. Over-closure of the mouth

As the result from attrition of front teeth and lost of posterior chewing, patient tends to over close his jaw. This will make his face shorter and his lip looks thin and easily get fungal infection at the corner of the mouth

7. Traumatic occlusion and Jaw joint dysfunction

Missing teeth will cause parafunction (abnormal) chewing. For example, when the back teeth are missing, the front teeth will be used for grind. This abnormal force will be exerted to the remaining teeth causing bone resorption around the teeth and lead to gum problem and loosening of teeth. Heavy and abnormal chew will also causing the TMJ (jaw) joint pain.
Due to abnormal function, the remaining teeth have a very high chance of fracture.

Conclusion

Delay in restoring missing teeth will result in:
1. Loss of chewing
2. Difficult in restoration/replacing missing teeth
3. Poor dental aesthetic – short teeth, teeth gaping, deep bite
4. Poor facial aesthetic – over closure, short face, chin protrusion
4. Prone to dental decay, gum problem, tooth fracture, dentine hypersensitivity
5. And finally, making you look older….

Smile!!

Treatment Options for Replacing Missing Tooth/Teeth

Option 1: Denture

Advantages
1. Cheap
2. Complexity: Simple
3. No need needle injection
4. No need surgery (No pain)
5. Maintenance: Easy to take care
6. Treatment duration: Short 1 – 3 weeks
7. Easy to adjust, repair

Disadvantages
1. Feel like not real (fake teeth) – can be removed from the mouth
2. Uncomfortable – Big and bulky
3. Palate coverage – less taste when eating
4. Lower ridge coverage – no space for the tongue
5. Teeth is made of plastic – easily worn off & stained
6. Easily trap food
7. For one missing tooth – wearer is not willing to wear it, very uncomfortable
8. Chewing food not the same as the natural teeth
9. Easily break

Option 2: Bridge

Advantages
1. Feel like real teeth – cannot be removed
2. Highly aesthetic – Look like natural teeth (with full porcelain), multiple shade to select
3. Very comfortable – No palate or lower ridge coverage
4. Teeth is made of porcelain – strong, durable
5. Good for missing one or a few teeth
6. Can correct the abutment teeth to a desirable shape and position
7. Chewing food almost as real as natural teeth
8. No need surgery

Disadvantages
1. Price: Moderate
2. Complexity: Simple to complex
3. Required needle injection
4. Involved neighbour teeth – the neighbour teeth required to be ground for support
5. Easily trap food under the bridge
6. Maintenance: Difficult (Required to floss under the bridge)
7. Treatment duration: Medium 2 – 3 weeks
8. No suitable for cases such as free end saddle, fully or near to edentulous

Option 3: Dental Implant

Advantages
1. Feel like real teeth – porcelain is sitting on the implant
2. Highly aesthetic – Look like natural teeth (with full porcelain), multiple shade to select
3. Very comfortable – No palate or lower ridge coverage
4. Teeth is made of porcelain – strong, durable
5. Does not involve the neighbour teeth
6. Trap food: very minimal (just like natural teeth)
7. Maintenance: simple to take care (just like natural teeth)
8. Can replace missing teeth in edentulous and free end saddle
9. Chewing food almost as real as natural teeth

Disadvantages
1. Price: Expensive
2. Complexity: Complex – required good planning
3. Duration of treatment: Long 3 – 6 months
4. Required needle injection
5. Required to undergo surgery (maybe required second or third surgery)
6. Required sinus augmentation, bone harvesting if not enough bone height for implant insertion (additional cost, additional surgery….additional pain)
7. Higher risk of failure in smoker, diabetic and medically compromised patient
8. Risk of injuring other structure during implant insertion: ID nerve, antrum

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Denture

Dental Bridge

Dental Implant

 

Sterilization/Autoclave Unit

Sterilization

Dental instrument that are used or contaminated have to be cleaned and bacteria-free before reuse. Therefore, they need to be sterilized before use.  Sterilization is a term referring to any process that eliminates (removes) or kills all forms of life, including transmissible agents (such as fungi, bacteria, viruses, spore forms, etc.) present on a surface, contained in a fluid, in medication, or in a compound such as biological culture media. Sterilization can be achieved by applying the proper combination of heat, chemicals, irradiation, high pressure, and filtration. (Source from wikipedia)

Autoclave

In dentistry, we use autoclave to sterilize our dental instruments. Autoclave is a device to sterilize equipment and supplies by subjecting them to high pressure saturated steam at 121 °C or more, typically for 15–20 minutes depending on the size of the load and the contents. It was invented by Charles Chamberland in 1879, although a precursor known as the steam digester was created by Denis Papin in 1679. The name comes from Greek auto, ultimately meaning self, and Latin clavis meaning key — a self-locking device. (Source from wikipedia)

Most dental clinic use autoclave unit to sterilize their instruments. According to the European Standard EN 13060, autoclave are divided into:

Type B- It has 3-times per-vacuum preceding vacuum drying. It can be used on wrapped and hollow instruments, which means a piece of equipment can be sterilized now for use later. This is the most effective autoclave as the steam able to penetrates deep into the pouches/wrappers or even double pouched instruments.

Type S – Comes with a one times pre-vacuum and vacuum drying function and efficient quick spraying steam generator. It can’t be used to sterilize instruments which are double pouch or the instruments which are wrapped in the thick wrapper/pouch.

Type N – This autoclave comes without vacuum function, it can be used for hollow instruments and solid instruments.This autoclaves are only suitable for a specific type of

load–for solid, unwrapped instruments.

Autoclave type B
Autoclave type B

Type B European Standard Autoclave – It has the highest standard among the type S and type N. It allows deep penetration into pouched/wrapped instrument. Type B Autoclave used widely in operating theater and it is used by our clinic too.