Perio Sheet #6 By Mohammed Bader

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Perio Sheet #6 By Mohammed Bader

Post by Sura on 2/11/2012, 9:32 pm

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Sura

عدد المساهمات : 484
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تاريخ التسجيل : 2010-09-29

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Re: Perio Sheet #6 By Mohammed Bader

Post by Shadi Jarrar on 12/11/2012, 9:21 pm

Today’s lecture will talk about more advanced techniques related to the previous lectures (gingivectomy flaps...etc.)



All the lectures we took before was about basic techniques to reduce the pockets and gain more accessibility and visibility.

The initial phase of treatment we do to the patient does not fix the bone loss or the recession but it fixes the tooth mobility up to a certain extent, so the initial phase of therapy is not enough and we need another phases to correct the disease.

Using treatments such as scaling and root planning, maintenance therapy, and antimicrobial therapy, our goal is to control the pathogenic microflora to prevent further periodontal destruction.



Some cases we don’t see any recession, but when we do a flap for the same area we might find bone loss with furcation involvement.



Despite successful disease management during the initial phase, anatomic changes resulting from past disease activity often occur and must be corrected. If they are left untreated, these defects can provide a potential harbor for the re-establishment of the pathogenic microflora.



The 1st picture is a 3 wall defect (3 walls are intact and 1 wall is lost), the 2nd is a 2 wall defect, and the 3rd is a 1 wall defect.

In the interdental crater the bone between the 2 teeth is entirely lost.

The best type for prognosis is the 3 wall defect because there are more reservoirs of stem cells in the 3 wall more than the 2 and 1 wall defect. The epithelial invasion is faster in 3 wall defects than the others, and the bone regeneration can be spontaneous in the 3 wall defect.



Bone grafting materials:

First, medicine was a prosthetic medicine, the lost tissue was replaced by an artificial means (plastic, metal…) after that we used synthetic material that resembles bone, bone of human origin, and bone of animal origin.

Regeneration: is the reproduction or reconstruction of a lost or injured part (tissue). Periodontal regeneration implies the formation of new cementum with inserting collagen fibers (periodontal ligament) and bone. The regeneration is a subcategory of healing.

Repair: healing that does not completely restore the architecture or the function of the lost or injured tissue. Periodontal repair may include formation of long junctional epithelium, connective tissue attachment or ankylosis.

When we have a periodontitis, we lose part of the bone and periodontal ligament, in repair, we will have parallel connective tissue attachment, but in regeneration we restore the architecture to normal.

In healing, we have 4 tissues: epithelium, connective tissue, bone, periodontal ligament and cementum.

The order of tissue turnover rate from faster to slower is as follows: epithelium(being the fastest) then connective tissue then bone then periodontal ligament and cementum(being the slowest). That’s why we get long junctional epithelium, because the epithelium needs half the time that the connective tissue needs













Epithelial migration needs 14 days and the maturation needs 42 days, that’s why when we do extraction, after 14 days the socket will close.

Collagen formation needs 3 weeks and the maturation needs 1 week.

The revascularization needs about 15 days.

Bone formation happens during the collagen maturation and its maturation needs up to 2 years.

Regeneration techniques in order to regenerate the lost tissues are:

- Root conditioning procedures: at first they thought that conditioning the root surface will enhance the attachment of bone stem cells and periodontal ligament stem cells to the surface and once they populate the surface that means that they can regenerate the lost tissues (the problem is who will populate the surface 1st, if it was the epithelium alone, no collagen or bone will take place.

- Bone grafts and bone substitutes: which we are still using it.

- Guided tissue regeneration: the 1st experiment was on animals in 1981, the 1st person to talk about the guided tissue regeneration was in 1983, the 1st available product was in 1986.

- Biologic and biomimicry mediators: the 1st material was found in 1997 and started using it in 1999.



What do you need to get regeneration?

Regenerative Space + signaling molecules (growth factor)= repair

Regenerative Space + stem cells = repair

Stem cells + signaling molecules = repair

Regenerative space + stem cells + signaling molecules = regeneration



Assessment of periodontal wound healing :

1) Probing depth: after we did the surgery we wait a specific time (like in bone graft we wait 9 months) then we probe. Now when we probe we can’t know if the base of the pocket is bone or long junctional epithelium. So we can’t use the probing depth as a measure to know the type of regeneration happened because it depends on: a) the pressure that I use b) degree of health and degree of inflammation (more inflammation = more edema = more probing). So probing depth cannot be used to verify the success of regeneration.

2) Clinical attachment level: it’s better because we calculate what the attachment loss was and what did I loose or gain after therapy. But not every gain in clinical attachment means that we had full regeneration because it can be long junctional epithelium (repair)

3) Bone fill: we can measure it by 3 means:

a) Surgical entry (we usually do it with implants).

b) bone probing (bone sounding) (we give the patient anesthesia and enter the probe to the bone) .

c) Reproducible parallel radiographs (we take index (reference) with dura lay that have a slot for the x-ray, the film will always be placed in the same slot.

4) Histology: which is the only thing I can use to make sure that bone regeneration took place, but we can’t use it with patients because it’s unethical.



Types of available bone grafts according to origin

- Autogenous graft: (we take it from the same patient).

- Allogenous graft: (we take it from another human being and remove all the immunogenic material so no rejection happen)

- Xenogenous graft: the most selling bone graft material in the world except in Jordan, and it’s of 3 origin: 1)bovine (from cows), 2) porcine (from pork), 3) equine (from horses).

- Alloplastic materials: synthetic materials or treated biological origin like coral reefs.



Types of available bone grafts according to activity:

- Osteogenic: it can synthesize bone by itself (it contains cells).

- Osteoinductive: it stimulates bone (it contains factors).

- Osteoconductive: it allows the adhesion of the cells so they can regenerate lost tissues.

After we put the bone graft, the 1st thing that happen is invasion and after that bone formation



Autogenous bone grafts:

Is the only bone graft material that is osteogenic because it’s the only type that contains cells and signaling molecules and scaffold (network).

Bone grafts can be:

Extra oral:

- From the iliac crest: which has the most osteogenic and regenerative potentials because its rich of stem cells.

The problem with extra oral graft is we need a secondary site (major surgery), higher morbidity, and the reservoir is limited (I can’t take all the hip).









Intra oral:

- From edentulous ridge (if we don’t need it)

- Maxillary tuberosity

- Mandibular ramus: which is most commonly used

- Tori and exostosis

- Anterior mandible: the 2nd most commonly used

The problem in the mandible is that it is highly cortical .

The autogenous bone graft can do bone fill up to 3-4 mm according to the studies

Iliac crest grafts have the ability to regenerate periodontium horizontally or with zero wall defects.

(Zero wall defects cannot be regenerated but there are some studies succeeded to do bone regeneration to zero wall defects by the iliac crest).







Mohammad Bader
6th perio lecture
24/10
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Shadi Jarrar
مشرف عام

عدد المساهمات : 997
النشاط : 12
تاريخ التسجيل : 2009-08-28
العمر : 26
الموقع : Amman-Jordan

http://jude.my-rpg.com

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