Rafael_TFO Flashcards
Who invented the Co-Destruction Theory? What are the two zones?
Glickmann ‘63: Invented the Co-Destruction Theory. Tissue destruction occurs due to trauma combined with irritation; they act synergistically.
* Zone of irritation: Marginal gingival and the papilla -basically, everything coronal to the CT attachment. (Trauma does not affect here).
* Zone of Co-destruction: basically, everything apical to the CT attachment. Theory is that the inflammation spreads along the transeptal and alveolar crest fibers and goes deeper into the tissues, causing destruction
What is Waerhaug’s theory about trauma and occlusion?
Waerhaug ‘79a and 79b: Trauma does not contribute to periodontal defect formation. (Cadaver studies, and Waerhaug did not like Glickmann)
What study models, force types, force devices, and defects were studied by the Glickman vs. Waerhaug groups?
Glickman: Dogs, monkeys, cadavers. Heavy and short-term forces
* Horizontal jiggling movements; used cap splints, bar-and-springs
* Defects were infrabony
Waerhaug: monkeys, cadavers. Light and long-term forces.
* Lateral jiggling movements; wedges, toothpicks, ortho elastics
* Defects were supracrestal
What are the 11 signs of TFO? Name them all
Fan & Caton ‘18:
Occlusal discrepancies
Wear facets
Fractured tooth
Cemental tear
Root resorption
Widened PDL
Mobility
Fremitus
Tooth migration
Discomfort / pain on chewing
Thermal sensitivity
How do mobile teeth respond to periodontal treatment? (Hint: classic 80’s study)
Fleszar ‘80: Pockets of clinically mobile teeth “do not respond as well” to periodontal therapy
What is the effect of occlusal adjustment in SRP?
Burgett ‘92: 0.5 mm greater CAL gain if occlusal adjustment was done with SRP
Is splinting beneficial?
Alkan ‘01: Nope, it doesn’t affect the final mobility of the teeth
Schulz ‘00: Yes, splinting leads to better outcomes in periodontal reconstructive surgery
Kleinfelder & Ludwig ‘02: Nope, doesn’t affect the bite force on the teeth
Describe the dog and monkey studies on TFO
gottlieb & orban 1931 33 dogs: high crowns on the left side for 48 hours. Concluded that there was no effect on the attachment levels and pocket depths, and therefore, did not cause periodontitis. =No, did not increase progression of periodontitis
Lindhe & Svanberg 1974 6 beagle dogs- used the cap splint & bar device, for 180 days. Test teeth (with the cap splint & bar device) showed gradual increase in mobility, horizontal bone loss, angular bony defects (which were not seen in the control group), and more apical proliferation of pocket. = yes, did increase progression of periodontitis
Ericsson & Lindhe 1977 15 dogs with ligature-induced periodontitis, then plaque removed. Test group added jiggling forces. Result: TFO did not initiate destruction in reduced but non-inflamed periodontium; there was no apical migration of the JE caused by TFO.
Polson et al. 1974 a and b Squirrel monkeys, used ortho elastics / toothpicks wedged between the teeth. Found no differences between test vs. control groups with regards to disease progression (but only followed for the short-term- 48 hours to 3 weeks).
What are the two “camps” for TFO?
Glickman camp (Glickman, Lindhe, Ramfjord, Nyman):
“TFO causes periodontal tissue injury”
* Zone of irritation
* Zone of co-destruction
Papers: Glickman & Smulow 1965: Human histology using 3 cadaver jaws. Compared marginal inflammation and inflammation going past the margin - when inflammation extends beyond the margin, TFO acts as a co-destructive factor in periodontitis. (Critique: cadavers; how was occlusion assessed?)
Waerhaug Camp (Waerhaug, Polson)
“TFO does not increase periodontal destruction or initiate it.”
Papers: Waerhaug 1979a Cadaver study (from subjects of violent death) : 64 sets of teeth. Extracted the teeth & examined the plaque-free zone. Found “no evidence” to support that traumatic occlusion acts as a co-factor of periodontal destruction.
Polson 1974a and 1974b Squirrel monkey study- ligature-induced periodontitis (toothpick wedges / ortho elastics for 48 hours). Also tested thermal trauma. Results showed vertical defects appeared only at the ligature-induced sites, showing that thermal trauma plays no role. The histology of the wedged sites showed PDL necrosis at 3 weeks and resorption of the bone. = no sig. differences between the test and control groups.
What is the plaque-free zone average distance?
0.53 mm
from Waerhaug 1979b
What are the human studies looking at TFO & periodontitis progression?
Harrel & Nunn 2001 Private practice perio patients (30 non-treated, 18 nonsurgical tx only, 41 surgical treatment) - adjusted for smoking and poor OH. Results: strong association between occlusal discrepancies and clinical parameters indicative of periodontitis (PD, mobility) = occlusal discrepancies are an independent risk factor for periodontitis.
Describe 2 studies on how normal vs. excessive occlusion affects implants
Berglundh et al 2005: 6 beagle dogs. Extracted all mandibular premolars. 3 mo later, installed Astra implants on one side, and Branemark on the other side and restored after another 3 mo. Test group: Functionally loaded implants; control group: no implant loading. Animals sacrificed at 10 mo. Results: functional (normal) implant loading may enhance osseointegration and does not result in marginal bone loss. Note: study sponsored by Astra
Isidor 1996: 4 Monkeys, 5 Astra implants each. Prostheses were designed to create a lateral displacement force on the implants on function. Implants with prostheses cleaned each month; others had ligature-induced plaque accumulation Results: loss of osseointegration seen in implants with the occlusal load; no loss of osseointegration in the implants with plaque accumulation (but the plaque implants had 1.8mm marginal loss)
How does occlusal adjustment affect SRP / Mod Widman results?
Burgett et al 1992 Randomly assigned ~22 patients in each group to SRP/Mod Widman + occlusal adjustment, versus SRP/Mod Widman without occlusal adjustment.
Results: 0.39 and 0.40mm greater CAL at 1 year and 2 years, respectively, in favor of the occlusal adjustment groups. = occlusal adjustment should be done early on (in the hygienic phase).
