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DENTAL IMPLANTS AND RECENT ADVANCES

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Bone necrosis caused by over compression during insertion of implant

Posted on 17 June, 2019 at 23:05 Comments comments (3)



Bone necrosis caused by over compression during insertion of implant after tooth removal. 

Symptoms include resorption of bone around compressed area, radiolucency on radiograph (c)

Complaint from the patient about continuous discomfort

Solution is to remove implant and affected tissue (d)

Graft the area for delayed new implant placement


Dental Implants - FAQ

Posted on 22 March, 2016 at 0:50

Information Regarding Dental Implants

 

 

What are dental Implants?

A dental implant is an artificial tooth root that is placed into your jaw to hold a replacement tooth, bridge or even a full denture. Dental Implants are made of pure titanium, a material that is totally bio compatible (compatible with body tissues) and actually integrates with the surrounding bone and becomes part of the body. Dental implants are an effective, safe and predictable solution to the problems resulting from missing teeth.

 

Why should teeth be replaced?

Apart from being able to smile, eat, and speak better; dental implants prevent the onset of poor facial profile due to loss of bone mass in your jaw bone. Dental Implants prevent bone loss by transmitting load forces during the chewing process down into the jawbone. The jawbone reacts to this loading by increasing the bone density. Dental Implants are well known in their ability to stop bone loss and restore facial skeletal structure while significantly improving nutrition.

 

There are many unfavorable consequences from loss of teeth without replacement:

• Drifting of adjacent teeth: when there is a missing gap, opposing teeth may over-erupt adjacent teeth drift into the empty spaces resulting in food trapping and possible decay

• Difficulty of chewing : missing teeth causes issues in chewing that could possibly result in indigestion

• Poor appearance & bone loss: loss of youthful and facial structure appearance due to bone resorption

• Loss of lip support

• Poor speech : difficulty in speaking specially if front teeth is missing

 

Am I a candidate for dental Implants?

 

Dental implants are the best option for people of all ages in good general oral health who have lost a tooth or teeth due to an accident, gum disease, an injury,or some other reason. It is important that you have enough dental bone to support the implant. There are some health conditions that warrant special consideration. Certain chronic diseases, heavy smoking, or alcohol abuse may contraindicate implant treatment. After careful evaluation of your health history, our dentists will alert you to any conditions that may effect your treatment. Remember, age is not a factor.

 

Do I have enough bone?

It is important for a patient to have enough bone to support an implant. If you do not have enough bone, there are many safe and effective ways to correct bone deficiency. Our implantologist will assess you and advise you if additional bone material is needed. It may be necessary for him to perform an artificial bone replacement or sinus lift before the implant can be placed.

What are some of the benefits of dental implants?

Dental implants are so natural-looking and feeling, you may forget you ever lost a tooth. Perhaps you hide your smile because you are embarrassed by your missing teeth. Maybe your dentures don't feel secure. Perhaps you have difficulty chewing. If you are missing one or more teeth and would like to smile, speak and eat again with comfort and confidence, implants could be the answer. Dental implants are especially practical for patients who can no longer wear removable dentures.

• Renewed ability to chew and speak properly

• Restoration of facial aesthetics

• Preservation of remaining jaw bone structure

• Recovery of the natural appearance and function of teeth

• Increased confidence and self-esteem

 

Dental Implant Procedure?

Dental implant treatment is arranged in the following steps:

• Insertion of the Implant ( usually 10 min procedure for single tooth)

• Healing of the gum and bone ( takes 2- 6 months)

• Exposure of the Implant site ( 10 min procedure)

• Taking the impression ( 10 min procedure)

• Insertion of crown or over-denture

The placement of the implant is followed by a healing period of between 3 and 6 months in which the bone bonds to the implant. If sinus lift or artificial bone replacement is necessary maybe more.

 

At the end of the healing period, a return visit of between 5 and 15 days is required for the fitting of crown. Many patients can divide the second stage into two parts, with a 1-2 week break in between.

 

Is there pain or discomfort?

Many patients report dental implant surgery to be less troublesome than having teeth removed. The dental implants are placed using a simple local anaesthetic, and sometimes with sedation if you are very nervous. Most patients report that they were much more comfortable following the procedure than they had anticipated.

 

Will I be without replacement teeth at any time?

There are several different ways to get temporary teeth during the healing period. Most people just wear their existing denture during this time. Some people have been without teeth for a long time and so are happy to go without temporaries for a few months. For those who are not it is usually possible to get fixed or removable temporary teeth. Fixed temporaries are more expensive as they are dental bridges bonded to the adjacent teeth. Removable teeth such as dentures may be made by a laboratory or you may use your existing dentures with a little adjustment during the healing phase.

 

How long does the treatment take?

The placement of the implant requires a visit of 3-5 days and is followed by a healing period of between 3 and 6 months during which time the bone bonds to the implant. You can wear your denture during this healing time. At the end of the healing period, a return visit of between 5 and 15 days is required for the fitting of All ceramic crowns or over-denture. Many patients can divide the second stage into two shorter visits, with a 1-2 week break in between.

 

How long will my implants last?

Under proper conditions and with diligent oral hygiene, dental implants can last a lifetime.

 

Classification of Implant implant success, survival, and failure.

Posted on 21 March, 2016 at 23:45 Comments comments (0)



Developed by Misch. On 5th October, 2007, a Pisa, Italy Consensus Conference (sponsored by the International Congress of Oral Implantologists) modified the James–Misch Health Scale and approved 4 clinical category that contain conditions of implant success, survival, and failure.


Implant Components

Posted on 21 March, 2016 at 14:10 Comments comments (1)



A precise, consistent terminology is fundamental to our ability to communicate. This must be a routine terminology, unambiguous and descriptive. Such proper terminology makes it possible to introduce a touch of philosophy in every aspect of a discussion.

1. Oral Implantology/Implant Dentistry:

It is the science and discipline concerned with the diagnosis, design, insertion, restoration, and/or management of alloplastic or autogenous oral structures to restore the loss of contour, comfort, function, esthetics, speech and/or health of the partially/completely edentulous patient.

2. Implant Prosthodontics:

It is the branch of implant dentistry concerned with the restorative phase following implant placement and the overall treatment plan component before the placement of implants.

3. Oral/Dental Implant:

It is a biologic or alloplastic biomaterial surgically inserted into soft/hard tissues of the mouth for functional cosmetic purposes.

4. Osseointegration:

It is the term that denotes at least some direct contact of lining bone with the surface of an implant at the light microscopic level of magnification under a functional load.

5. Rigid Fixation:

The term defines an implant with no observed mobility with 1-500gm force applied in vertical/horizontal direction.

6. Endosteal Implant:

It is an alloplastic material surgically inserted into a residual ridge, primarily to serve as a prosthodontic foundation

7. Root form Implant:

Implants designed to use a vertical column of bone. They can be smooth, threaded, perforated, solid, hollow, vented, coated or textured and are available in submergible and non-submergible forms in a variety of biocompatibile materials. They may be cylindrical or screw root forms.

8. Blade form Implants:

This form uses a horizontal dimension of bone and is flat and narrow in the faciolingual dimension.

9. Implant body/Fixture:

Is that part of implant designed to be surgically placed in the bone and may extend slightly above the crest of the alveolar ridge

10. Cover Screw:

These are first stage covers placed on top of the implant to prevent bone, soft tissue, or debris from invading the abutment connection area during healing.

11. Abutment:

It is that portion of the implant that serves to support and/or retain the a prosthesis or implant superstructure

12. Superstructure:

It is defined as a metal framework that fits the implant abutment and provides retention for prosthesis such as a cast bar retaining an overdenture with attachments

13. Impression coping:

It is a structure positioned onto the abutments prior to impression making, picked up in the impression and used to position an anolog in the impression. It can be direct/indirect.

Direct: It is picked up within the impression after loosening its screw from the abutment

Indirect: It remains in place in the mouth after the impression is removed and is subsequently reoriented in the impression before attaching the analog.

14. Implant analog:

It is attached to the transfer coping and then the assembly is poured; to replicate the retentive position of the implant body/abutment.

 

Cumulative Interceptive Supportive Therapy (CIST) protocol

Posted on 21 March, 2016 at 14:05 Comments comments (27)


In part A of the CIST protocol, typically initiated whenplaque and BOP are present but PDs are 3 mm or less, patients are re-instructed in oral hygiene and motivated to initiate and continue maintenance; mechanical debridement is performed using nonmetallic curettes; and polishing takes place using a rubber cup andnonabrasive polishing paste.

Part B, when PDs of 4 to 5 mm are found, consists of antiseptic treatment. Here, chemical plaque control isperformed using chlorhexidine digluconate, typically as mouthrinses with 0.1% to 0.2% chlorhexidine for 30 seconds using approximately10 mL, application of local chlorhexidine gel (0.2%), and/or local irrigation with chlorhexidine (0.2%), 2 times a day for 3 to 4 weeks.

Protocol C, systemic or local antibiotic treatment, is initiated when PDs are greater than 5 mm. In addition, radiography should be used to supplementclinical findings. Typical systemic treatment is with ornidazole (1,000 mg 1) or metronidazole (250 mg 3) for 10 days, or acombination of amoxicillin (375 mg 3) and metronidazole (250 mg 3) for 10 days. Local treatment might include local application ofantibiotics using a controlled-release device for 10 days, eg, tetracycline fibers and minocycline microspheres.

Once treatment modalitiesA, B, and C have been completed, a surgical approach (D) may be considered. Surgical therapy for peri-implantitis should be performed in conjunction with systemic antibiotics and implant surface decontamination. If  regenerative treatment is chosen, a barrier membrane techniquealone or in combination with autogenous grafts and/or bone substitutes (deproteinized bovine bone mineral) may be considered.

Resective surgery may be considered when the peri-implant defect is not suitable for regenerative techniques.

Basic Surgical Principles - Implant Placement

Posted on 21 March, 2016 at 13:05 Comments comments (9)

The basic surgical principles related to the placement of dental implants in partially

edentulous patients. Surgeons must take important measures preoperatively to prevent postsurgical infection, handle surgical instruments expertly to preserve soft tissues, and carefully accomplish adequate implant site preparation without overheating the bone. Precise surgical protocol includes the following precautions:

• Preoperative mouthwash with 0.1% chlorhexidine

• Perioral skin disinfection with alcohol solution

• Antibiotic prophylaxis 2 hours prior to surgery (eg, 2 g amoxicillin intraorally)

• Low-speed drilling (between 800 and 1200 rpm)

• Cooling spray during drilling with chilled sterile saline

• Intermittent drilling technique

• Use of sharp drills

It is important to perform a surgical procedure systematically, always applying the same surgical principles.

 

Once the implant surgical site has been exposed, a large round bur is used to smooth and level the crest of the alveolar ridge

 

Round bur is used to mark the position of the implant site

                                   

 

Initial implant site preparation is made with a 2.0-mm-diameter pilot drill




 

2.0-mm-diameter guide pin is inserted into the initial preparation to check its position and axis and a digital X ray is taken to confirm the same

        

 

Preparation of the implant site continues with the 2.8, 3.5-mm-diameter spiral drill (in increasing order)



 

A standard implant of 4.2 mm diameter is placed in the site, with the rough surface positioned at the level of the alveolar ridge crest. This allows the implant shoulder to be located at the gingival level


 

If the implant site is prepared with the 12-mm mark slightly below the crest, the rough border of the inserted implant will be positioned approximately 0.5 mm below the crest. This approach is most often used in posterior implant sites for a non-submerged implant healing

 

Dental Implant Complication -Neurosensory disturbances

Posted on Comments comments (5)

The inferior alveolar nerve is midway between the buccal and lingual cortical plates in the first molar region. In about 1% of patients, however, the mandibular canal bifurcates in the inferior superior or medial lateral planes. Thus, a bifurcated mandibular canal will manifest more than one mental foramen. This may or may not be seen on panoramic or periapical films. Therefore it is suggested that clinicians should consider obtaining a preoperative CBCT to avoid nerve injuries prior to implant placement above the inferior alveolar canal. A mean incidence of neurosensory disturbance incidence after implant surgery was 6.1% (Goodacre et al., 1999) to 7% (Goodacre et al., 2003), with a range between 0.6% and 39%. Nerve damage can have results ranging from mild paresthesia to complete anesthesia or even disabling dysesthesia.


1. Neurapraxia - There is no loss of continuity of the nerve; it has been stretched or has undergone blunt trauma. The parasthesia will subside, and feeling will return in days to weeks.

2. Axonotmesis - Nerve is damaged but not severed; feeling returns within 2 to 6 months.

3. Neurotmesis - Severed nerve; poor prognosis for resolution of parasthesia.


Possible causes of nerve injury include poor flap design, traumatic flap reflection, accidental intraneural injection, traction on the mental nerve in an elevated flap, penetration of the osteotomy preparation and compression of the implant body into the canal. Nerve injuries may be caused indirectly by postsurgical intra-alveolar edema or hematomas that produce a temporary pressure increase, especially inside the mandibular canal. Direct traumas are the most frequent causes of nerve injury, and they may occur through five mechanisms: compression, stretch, cut, overheating, and accidental puncture. Finally, prolonged pressure from neuritis may lead to the permanent degeneration of the affected nerve.


An inferior alveolar nerve injury after implant placement.

 


The mental nerve is at particular risk of iatrogenic injury because it arises from asymmetric foramina and forms a concave loop anteriorly. In edentulous patients, it may be very close to the bone surface or the top of the crest.

The nerve injury may cause one of the following conditions:

1. parasthesia (numb feeling),

2. hypoesthesia (reduced feeling),

3. hyperesthesia (increased sensitivity),

4. dysthesia (painful sensation),

   or anesthesia (complete loss of feeling) of the teeth, the lower lip, or the surrounding skin and mucosa


Overpenetration occurs when the cortical portion of the alveolar crest places resistance on the drill. However, as it enters the marrow spaces, a drill may drop into the neurovascular bundle unless the surgeon has excellent control.

For implants placed in the atrophic posterior mandible, the routine use of intraoperative periapical radiographs during the drilling sequence can help avoid the risk of injury to the inferior alveolar nerve. Periapical radiographs used intraoperatively to obtain working length measurements are similar in concept to techniques used in root canal therapy. This method can reliably determine safe distances between the implant and the inferior alveolar canal, thus avoiding the risk of injury to the nerve altogether. A safety margin of 2 mm between the entire implant body and any nerve canal should be maintained. Additionally, surgical placements of implants should be at least 3 mm in front of the mental foramen . When placing implants in proximity to the mental foramen, the clinician must take into consideration the anterior loop of the nerve and the available bone above the mental foramen, because the inferior alveolar nerve often rises as it approaches the mental foramen. Finally, although the depths of the implant bur are variable, the drill bur may be longer than the implant according to the manufacturers.


If an implant is in danger of violating the canal, its depth should be decreased in the bone (i., by unscrewing it a few turns) and left short of the canal or removed. Because the altered sensation may be due to an inflammatory reaction, a course of steroid treatment or a high dose of nonsteroidal anti-inflammatory medication (e.g., ibuprofen [800 milligrams] three times per day) should be prescribed for three weeks. Adjunct drugs such as clonazepam, carbamazepine, or vitamin B-complex might alleviate neuritis via their known neuronal anti-inflammatory actions.

 


If improvement is noted at three weeks on the basis of a repeated neurosensory examination, the clinician can prescribe an additional three weeks of anti-inflammatory drug treatment. If the improvement is seen, however, the patient should be referred to a microneurosurgeon.

Recommendations to avoid nerve injuries during implant placement

1. Measure the radiograph with care. Apply the correct magnification factor.

2. Consider the bony crestal anatomy: If the ridge is thin buccolingually, is this useless bone or should an augmentation procedure be done? Is the buccolingual position of the crestal peak of bone influencing the measurement of available bone?

3. Consider the buccolingual position of the nerve canal (CBCT)

4. Allow a 1 to 2 mm safety zone.

5. Use a drill guard.

6. Take care with countersinking not to lose support of the crestal cortical bone.

7. Take a radiograph after initial osteotomy.

 



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