About Dental Implants Part 1 & 2 | Intelligent Dental

About Dental Implants Part 1 | Intelligent Dental

Dental implants are now increasingly used to attach crowns, bridges or dentures by anchorage to bone. Despite its benefits, placement of implants requires careful patient selection and treatment planning to ensure long-term success of implants.

History of dental implants

In 1952, professor Branemark, a Swedish surgeon, while conducting research into the healing patterns of bone tissue, accidentally discovered that pure titanium comes into direct contact with the living bone tissue, the two literally grow together to form a permanent biological adhesion. He named this phenomenon ‘osseointegration’.

Indications for dental implant treatment

© seapointclinic.ie

• Difficult toothless cases


• Long span dental bridges


• Free end saddles of partial dentures


• Single tooth replacement

Contraindications to tooth implant placement

• Acute illness


• Severe lesions of mucous membranes


• Poor bone quality


• Uncontrolled metabolic disease


• Tumor radiation to implant site


• Unrealistic expectations


• Improper motivation


• Lack of operator experience


• Unable to restore with prostheses


• Cardiac disease – patients with risk of endocarditis may be suitable but regular monitoring is advisable. Contraindicated in severe heart disease


• Hematological disease – contraindicated in hemophilia, relative contraindication for those under Warfarin therapy


• Immunological problems – implant survival may be reduced in patients on corticosteroids and this should be balanced against potential benefits. Smoking has adverse effects on implants


• Bone disorders – most bone disorders are contraindicated. Relative contraindications for osteoporosis

Osseointegation

© feppd.org

Osseointegration was defined as ‘a direct structural and functional connection between living bone and the surface of a load carrying implant’. It is in fact an ankylosis of implant to bone surface and some prefer the term functional ankylosis. Osseointegration is prerequisite for success of implant placement.

Factors required for successful osseointegration

• A suitable biocompatible material


• Host bed


• Adaptation of implant to prepared bone site


• Adequate bone quality and quantity


• Atraumatic surgery to minimize tissue damage


• An immobile, undisturbed healing phase


• Soft tissue to implant interface

Suitable biocompatible material

This is necessary to promote healing without a foreign body rejection by host tissue. If biocompatible materials are not used, bone attempts to isolate the foreign body by surrounding it with granulation tissue and then connective tissue. Researchers have demonstrated that titanium and certain calcium-phosphate ceramics are biologically inert.

Host bed

In cortical (outer layer) bone resorption of mineralized, avascular necrotic tissue must occur before new bone can form on the implant surface. In the spongious (inner layer) region of the site, on the other hand, woven bone formation and osseointegration occurs early in the process of healing.

Adaptation of implant to prepared bone site

Site of gap between the implant and the bone immediately after implant placement is critical to achieving osseointegration. Gap size can be controlled primarily by the preparation of a precise surgical bed. Precision instrumentation and technically sound surgical procedure minimize the distance between the implant and host bone.

Atraumatic surgery to minimize tissue trauma

Atraumatic surgery is required to allow minimal and thermal injury to occur.

Adequate bone quality and quantity

© berksoralsurgery.com

Implant immobility during the healing phase is affected by bone quality and quantity. Areas with high cortical (outer layer) bone such as the front of the lower jaw are more likely to anchor the implant successfully. Initial stability takes long time to achieve in cancellous (porous) bone. Implant stability increases if both superior and inferior cortical plates are used.

Upper jaw

• cortical plate of upper jaw is often thin or absent and normally crumbles,


• pattern of bone resorption  and anatomical structures in upper jaw cause problems,


• resorption causes bone loss from front and crestal surfaces

Lower jaw

• more cortical bone so better success rate,


• resorption in lower jaw does not pose problem with implant placement but there is severe loss of bone height

 Methods of improving implant success in the upper jaw

© drlampee.com

• Use additional implants to share the load


• Use connecting bars


• Use maximum length of implant


• Consider augmentation of ridge bone


• Consider sinus lift to extend available ridge


• Allow more time for osseointegration

Undisturbed healing phase

It is fundamental that undue loading is avoided until osseointegration is achieved.

Minimum integration time

Region of implant placement	Minimum integration time
Front of the lower jaw	3 months
Back of the lower jaw	4 months
Front of the upper jaw	6 months
Back of the upper jaw	6 months
Into bone graft	6 to 9 months

Soft tissue to implant interface

Successful dental implant should have an unbroken, perimucosal seal between soft tissues and implant abutment surface. To maintain the integrity of this seal, the individual must maintain a high level of oral hygiene. If the seal between soft tissue and implant is lost, the gum pocket can extend directly to bony structures. Therefore if the seal breaks down or is not present, the area is subject to peri-implant gum disease – peri-implantitis

Components of implants

© http://www.orofacialsurgery.com.sg

Implant

Implant is the endosteal (within bone) material that is placed within the bone during stage 1 dental implant surgery. It is either titanium or titanium alloy, with or without hydroxyapatite coating.

Cover screw

A screw is placed in the implant during the healing phase after stage 1 surgery. This crew is usually to facilitate easy suturing of the soft tissue over the implant. At stage 2 dental implant procedure screw is removed and replaced with subsequent components.

Healing cap

Healing cap is a dome-shaped screw that is placed after stage 2 surgery and before prosthesis placement. The cap may be made out of resin, such as polyoxyethylene, or one of the titanium metals.

Abutment

Abutment is that component of the implant system that screws directly into the implant. The abutment will eventually directly support the prosthesis. It is smooth, polished straight-sided titanium. The length may range from 1 to 10 millimeters.

Impression post

The impression post facilitates the transfer of intra oral location of fixture or abutment to a similar position in the laboratory cast. Impression post is then removed from the mouth and joined to the lab analogue before being transferred into the impression.

Laboratory analog

Laboratory analog is a component machined to exactly represent either the implant or the abutment in lab cast.

Waxing sleeve

Waxing sleeve is attached to the abutment by the prosthesis=retaining screw on a lab model. Waxing sleeve will eventually become a part of the prosthesis. It may be a plastic pattern that is burned out inside the investment and replaced by a cast precious alloy.

Prosthesis-retained screw

Prosthesis-retaining screw penetrates the fixed restoration and secures it to the abutment. In non-segmented restorations the screw tightens the abutment directly to implant. The screw can be made of titanium, titanium alloy, or gold alloy.

Implant material

Titanium

Titanium is the best material available at present. It oxidizes in the atmosphere to form an inert surface layer of titanium oxide. It has good mechanical properties. Other materials – niobium, hydroxyapatite are well-tolerated.  Hydroxyapatite can be used as coating which is osteoinductive. Aluminum oxides, cobalt-chrome, molybdenum ad stainless steels are less tolerated.

Examination of implant site

Clinical examination

Visual inspection and palpation is done to check for flabby excess tissue, narrow bony ridges, sharp underlying ridges and undercuts.

Radiographic examination

CT scan © http://www.orofacialsurgery.com.sg

• Orthopantomograph (OPG) – to assess vertical bone height,


• Lateral cephalometric film – width of front upper jaw and lower jaw,


• CT scan – to locate inferior alveolar canal and upper jaw sinus and to evaluate ridge form

Study casts

Duplicates can be used for diagnostic wax-up so that the tooth position can be planned. A template can be made with indicator holes drilled as an aid to the surgeon so that the implants are placed in optimal position.

Principles of dental implant surgery

First surgical phase (implant placement)

© http://www.orofacialsurgery.com.sg

Under local anesthesia the dentist places dental implants into the jaw bone with a very precise surgical procedure. The implant remains covered by gum tissue while fusing to the jaw bone.

Second surgical phase (implant uncover)

The length of time necessary to achieve integration varies from site to site. After satisfactory integration of implant uncovering of implant is done to attach the abutment to it with preservation of attached tissues.

Prosthetic phase

Once the gums have healed, an implant crown is fabricated and screwed down to the implant.

Post operative care

Implant survival depends on proper and timely home care and maintenance. The goal of implant maintenance is to eradicate microbial population. Recall visits should be scheduled at least every 3 months for the first year. The area surrounding the implant should be removed of calculus by using plastic or wooden scalers. A rubber cup with low abrasive polishing paste or tin oxide may be used to polish implant abutments.
Points to be evaluated during recall:

• Mobility of implant,


• bleeding,


• framework fit,


• occlusion

Problems involved in dental implants placement

Poor positioning of implants © nature.com

• Improper angulation of implant


• Improper position of implant


• Perforation of maxillary sinus


• Perforation of inferior alveolar canal


• Dehiscence (splitting up) of bucco-cortical or linguo-cortical bone plate


• Lower jaw fracture (in case of thin lower jaw)


• Soft tissue wound dehiscence

Criteria for success of implants

• The individual unattached implant is immobile when tested clinically


• No evidence of peri-implant radiolucency is present as assessed on an undistorted radiograph


• The mean vertical bone loss should be less than 0.02mm annually after the first year of service


• No persistent pain, discomfort or infection is attributable to implants


• The implant design does not preclude placement of a crown or prosthesis with an appearance that is satisfactory to the individual and the dentist.

Dentist Glendale CA, What is a Dental Post? Dr. Kamran Sahabi

Uploaded by drkamransahabi on Nov 29, 2010

http://dentistinglendaleca.com

Dentist Glendale CA, Dr. Kamran Sahabi, speaks about dental posts and tooth loss. A dental post is a dental restoration used to sufficiently build-up tooth structure for future restoration with a crown when there is not enough tooth structure to properly retain the crown, due to loss of tooth structure to either decay or fracture. Dr. Kamran Sahabi mentions that all dental procedures aren't the same and that every doctor has its own philosophy of treatment. For more information about dental posts, visit dentist Glendale CA, Dr. Kamran Sahabi's website today. For more videos visit http://www.youtube.com/user/drkamransahabi?feature=mhum

Dr. Kamran Sahabi also serves the following cities: Glendale CA, Montrose CA, Verdugo City CA, La Canada Flintdridge CA, La Cresenta CA, and Burbank CA.

Pins And Posts In Dentistry, Material Used For Pin And Post, Types Of Post, Advantages & Disadvantages | identalhub.com

Pins And Posts In Dentistry, Material Used For Pin And Post, Types Of Post, Advantages & Disadvantages | identalhub.com

What Are Pins and Posts in Dentistry

When the teeth are decayed and it has to be restored the dentist goes for the filling but sometimes the decay is extensive and a large part of the tooth is lost. In such cases pins and posts are used as the simple filling material can not give the adequate strength to sustain the masticatory forces and fractures. The pins and posts can be used separately or together as decided by the dentist.

Pins in Dentistry

There are many types of pins available in dentistry. They are basically thin metallic shafts. They are either cemented in the tooth after making the space for them or they are screwed in the tooth. They are used to give the strength to the filling. First the pins are placed in the tooth above that core built up is done and after that crown is given above that.

INDICATIONS

1. As additional aids of retention in badly broken down or mutilated teeth.


2. In teeth with poor prognosis i.e. endodontically and periodontically involved teeth.


3. When one or more cusps need capping.


4. Increased resistance and retention form is needed.

CLASSIFICATION
1.    Direct/non parallel pins- are inserted into Dentin followed by placement of restorative material directly over them.

Three major categories of direct pins are:

Cemented pins- pins are 0.001-0.002 inch smaller than their pin channels and the difference in diameter provides space for cementing medium. Are least retentive but virtually place no stress on surrounding dentin during or after placement.

Friction locked pins- are 0.001 inches larger than their pin channels and hence utilize the elasticity of dentin for retaining the tapped pins in a vise like grip. Better retention than cemented pins but generates stresses in dentin in the form of cracks or craze lines.

Threaded pins- are 0.0015-0.002 inches larger than their pin channels and like friction locked pins they are also retained by elasticity of dentin. Provides maximum retention but at the same time generates excessive stresses in the form of cracks in dentin.

Four sizes of TMS pins.
•    Regular ( 0.031 inch [0.78 mm]
•    Minim (0.024 inch [0.61 mm]
•    Minikin (0.019 inch [0.48 mm]
•    Minuta ( 0.015 inch [0.38 mm]

2.    Indirect/parallel pins- are an integral part of Cast restoration. These pins are placed parallel to each other as well as parallel to the path of insertion of the restoration.

MATERIALS USED
1.    Stainless steel
2.    Titanium
3.    Silver
4.    Cast gold alloys
5.    Platinum-palladium
6.    Platinum-iridium
7.    Plastic
8.    Aluminium
9.    Acrylic

PRINCIPLES OF PIN PLACEMENT

Most desirable locations for pin holes are corners of the tooth and least desirable are in the middle of facial, lingual, mesial and distal surfaces of a tooth.
Dentist should try and place pins in locations where they will be surrounded by optimum bulk of dentin and restorative material.

Minikin pins placed in maxillary second premolar and restoration built over pins

ADVANTAGES

1. Offer retention without the need for extensive preparation of tooth structure.


2. May increase resistance form of the tooth preparation to some extent.


3. Less time consuming and less expensive than cast restorations which require multiple appointments.

DISADVANTAGES

1. Do not increase the strength of the overlying restorative material.


2. Induce stresses in dentin in the form of cracks or craze lines, which may increase the potential for the fracture of tooth, micro leakage, pulpal damage etc.


3. Increase the chances of perforation into pulp or on the external tooth surface.

Posts in Dentistry

As compared to pins the posts are thicker than the pins and are used in the root canals after root canal treatment where the tooth loss is extensive. In the root canal the post is cemented or screwed and above that core built up is done. After the core built up crown is given. Now many types of posts are available.

INDICATIONS

1. Primary purpose is to retain a core in a tooth with extensive loss of coronal tooth structure.


2. If an Endodontically treated tooth is to receive a crown.


3. Pulp chambers are too small to provide adequate retention and resistance.

TYPES OF POSTS

1.    Active versus passive posts - Most active posts are threaded and are intended to engage the walls of canal, where as passive posts are retained strictly by the luting agent. Active posts are more retentive than the passive posts but introduce more stresses into the roots than the passive posts. Use of active posts should be limited to short roots in which maximum retention is needed.

2.    Parallel versus tapered posts -

• Parallel posts are more retentive than tapered.


• Induce less stress into the root.


• Less likely to cause root fracture.


• Have more success rate.


• Tapered posts on the other hand require less dentin removal.

Tapered post on the left side and Parallel post on the right side

3.    Prefabricated post and cores- are typically made of stainless steel, nickel chromium alloy or titanium alloy. They are very rigid, and with the exception of titanium alloys, are very strong. The main advantage is that they can be laced in the single visit and are quite economical as compared to the posts which are fabricated in the laboratory.

 

Prefabricated screw post

4.    Custom cast post and cores- These have fallen from favour because they require two appointments, temporization, and a laboratory fees. Offer advantage in certain clinical situations like when multiple teeth require post and core, malaligned tooth, or tooth with minimal crown structure.
5.    Ceramic and zirconium posts- These are aesthetic posts that are white and/or translucent but are weaker than metal posts, so a thicker post is necessary, which may require removal of additional radicular tooth structure.
6.    Fibre posts- were more flexible than metal posts and had approximately the same stiffness as of dentin. Can be made up of Carbon, Glass, Quartz and Silicon.

How the Post Space is Prepared

-Preservation of radicular dentin is important.
-Gutta-percha can be removed with the help of heat or chemicals.
-Post length equal to 3/4th of root canal length or at least equal to the length of the crown is required.
-At the same time 4-5mm of gutta-percha should remain apically to maintain adequate seal.
-Post diameter should not exceed 1/3rd of the root diameter.

What can be Complications While Inserting Post

1. Certain degree of risk to a restorative procedure.


2. Procedural accidents may occur during post space preparation that includes perforation in the apical portion of the root or into the lateral fluted areas of midroot, so called STRIP

PERFORATION.

3.    Also increases the chances of root fracture and treatment failure. 
                                                                                                
For these reasons, posts should only be used when other options are not available to retain a core.

Related Topics

What Are Pins and Posts in Dentistry

Types of Posts

Procedure For Post And Core

What Is Post And Core

Pros & Cons of Tooth Extractions | Intelligent Dental

Pros & Cons of Tooth Extractions | Intelligent Dental

When faced with an aching tooth, the first thing that comes to mind is to pull the miserable tooth out. However depending on the cause of the toothache, tooth extraction is not the only way out of the pain. There are many causes of toothache and there is a chance that the aching tooth could be saved.
Many people have to weigh the pros and cons of getting the tooth pulled or paying for the tooth to be repaired. This is not an easy decision to make, as there are several pros and cons for both tooth extraction and tooth repair. Therefore you need to know which option is best for you and your wallet before visiting a dentist.

Pros of teeth extractions

© toothextractioncost.info

Perhaps the most affordable option for dealing with a severely damaged or infected tooth is dental tooth extraction. Dental extraction costs typically range between about $99 and $300 for a tooth depending on locations. Extracting a completely erupted wisdom tooth or third molar would cost around $150 to $300 while extraction of a partially or completely impacted wisdom tooth will range between $300 and $700. Do keep in mind that the fees do not include initial surgical consultation, x-rays and medications.

If you don’t want to get your tooth pulled, then one of your tooth repair options is to have a root canal. Root canal costs are going to vary depending on which tooth is affected, how many root canals are needed and who your dentist is. However, you can expect the costs to range between $400 and $600 for a front tooth and between $500 and $900 a tooth for the back teeth or molars. An endodontist, specializing in tooth root problems, may charge up to 50 percent more. Root canal therapy usually requires around three to four appointments and no dental procedure is without risks. Pain, surgery and the chance of an infection developing may happen during root canal treatment.

Root canal treatment

Crowns are your second tooth repair option and are usually required after root canal procedure. The cost of a crown is going to depend on the crown’s material and the dentist. The overall cost of a crown is going to range between $600 and $3,000 per crown. The cost of this procedure is a major drawback for many people. Other drawbacks of crown placement include wearing down of other teeth with porcelain crowns, gold crowns are not attractive, porcelain crowns require the tooth be filed down and dental insurance typically won’t cover all care and costs associated with a crown procedure.

Dental abscess can form in a badly decayed or infected tooth and the quickest way to drain the pus would be tooth extraction.

Wisdom teeth that are impacted can predispose to pericoronitis, cavities, resorption of the tooth, gum problems, as well as cysts and tumors may arise.

Cons of tooth extractions

© myvegasdental.com

However, while an affordable option, tooth extraction will remove a tooth from your mouth leaving a gap that could reduce the functionality of your bite and can impair the cosmetic appearance of your smile. The missing tooth is usually replaced with a partial denture, dental bridge or dental implant which will require additional costs. If the void is not filled, the remaining teeth may naturally move to close the gap and lead to improper bite.

Furthermore, complications may occur during or after tooth extraction is done. Types of complications include:

1)      Post-extraction pain and swelling

2)      Soft tissue complications
a)      Tearing of mucosal flap due to inadequate size or large retraction force
b)      Puncture wound of soft tissues due to inadvertent puncturing of soft tissues with dental instruments
c)       Stretch or abrasion injury due to rotary instrument rubbing on soft tissues usually the lip

3)      Complications with tooth being extracted
a)      Root fracture
b)      Root displacement into the sinus
c)       Tooth lost in the oropharnyx

4)      Injuries to adjacent teeth
a)      Fracture of adjacent restoration or filling
b)      Fracture of adjacent teeth
c)       Extraction of wrong tooth

5)      Fracture of mandible

6)      Injuries to osseous structures
a)      Fracture of alveolar process
b)      Fracture of maxillary tuberosity (A rounded eminence behind the root of the upper wisdom tooth or third molar)

7)      Injuries to adjacent structures
a)      Injuries to regional nerves
b)      Injuries to the TMJ (temporomandibular joint)

8)      Oro-antral communication – communication between the sinus (Any of various air-filled cavities especially in the bones of the skull) and the oral cavity

9)      Post-extraction bleeding

10)   Delayed wound healing and infection
a)      Infection
b)      Dry socket
c)       Wound dehiscence

Pins and Posts

Pins and Posts

Pins and posts are aids used to reinforce fillings and crowns when a large part of the tooth is decayed or missing. Both pins and posts can be used in the same tooth, if necessary. Each situation is different. Your dentist will decide on a case-by-case basis if you need pins or posts.

Pins are thin shafts of metal that are either cemented or screwed into the tooth. They provide anchors for a filling or crown. Your dentist drills small holes in the tooth and places the pins. Then the filling is built around the pins or the crown is placed over them. There are several types of pins, including threaded, friction and roughened pins.

Today, we have newer materials that create both mechanical and chemical bonds to the tooth. For this reason, pins are used less often. The bonds help to keep the filling in place. In many cases, this eliminates the need for a pin. The shape of the tooth affects whether a pin is needed. So does the amount of force placed on the tooth when you bite. Pins do increase the risk of damaging the tooth.

Posts are thicker shafts of metal or composite materials used in teeth that have had root-canal treatment. In root canal treatment, the dentist removes the tooth's pulp. This is the part of the tooth that contains nerves and blood vessels. A post is placed through the center of the tooth, where the pulp used to be. It provides an anchor for a crown. Posts are either bonded or cemented in place. They can be prefabricated or individually made. 

There are many different types of post systems. They include parallel sided, tapered, threaded and serrated posts made of metals such as titanium or stainless steel.

Prefabricated posts are placed in one visit and cemented in place. The post serves as the anchor for a buildup of "core" material, which eventually will hold your crown. 

A prefabricated post can be completed in one visit. It is less expensive than a post and core made in a laboratory. However, the core material that is attached to the post is often made of composite or plastic material, glass ionomer or amalgam. This material can break or fail.

As an alternative, your dentist can have a one-piece post and core made in a laboratory (cast). A cast post and core is made from an impression of the tooth that your dentist will take after completing the root canal and preparing the tooth. 

Because a cast post and core is all one piece, it is stronger than a prefabricated post. Also, it is cemented in place. It does not stay in place using friction, as is often the case with prefabricated posts. A cast post and core is less likely than a prefabricated post to fracture your root. It does cost more than a prefabricated post and core, because of the additional time and materials needed. Cast post and cores also can be less likely to stay in place than the prefabricated kind, because they are held only by cement. However, cast posts and cores do not usually come loose.

Pins Dental

Pins Dental

When a tooth has very little left to rebuild upon, pins can be used to help hold the filling on. Pins do have a certain level of risk attached to them. There could be a chance that the pin will drill too close to the nerve of the tooth, causing pain (and leading towards root canal treatment). Also pins can weaken the remaining tooth structure causing microfractures in the tooth. Some dentists refrain from using pins for these reasons. However, without pins, the biting forces on a tooth like this would most probably knock the filling off. 
 

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Root Pin | Dental Video

Root Pin | Dental Video

 

Root Pin

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In dentistry, a root pin serves in the retention of artificial teeth. If a tooth has suffered such severe damage by cavities that nothing is left of the crown, crown treatment is no longer be possible, since the crown cannot be securely attached. But if the roots are still intact, then good root canal treatment and restoration of the tooth stump could provide enough support for a crown. Crowns supported by such artificial structures are called pivot crowns.

References

Produced: 02/2011

Source	Version	Author	Publisher
Root canal posts for the restoration of root filled teeth	2007	Bolla M, Muller-Bolla M, Borg C, Lupi-Pegurier L, Laplanche O, Leforestier E	The Cochrane Database
A systematic review of dowel (post) and core materials and systems.	2009	Theodosopoulou JN, Chochlidakis KM	J Prosthodont.
Biomechanical considerations for the restoration of endodontically treated teeth: a systematic review of the literature, Part II (Evaluation of fatigue behavior, interfaces, and in vivo studies).	2008	Dietschi D, Duc O, Krejci I, Sadan A.	Quintessence Int
Which type of post and core system should you use?	2007	Al-Ansari A.	Evid Based Dent.