Rick Cole


Reconstruction of the periodontium destroyed by periodontal disease may be considered an ultimate goal of reconstructive periodontal therapy. To date, there has been no concrete evidence demonstrating this phenomenon in humans. Garrett (1978) has shown that citric acid, after application to root planed tooth surfaces, produces a four micron wide demineralized zone which is characterized by exposed collagen fibers. It is impossible that this demineraIization may lead to new attachment by enhancing cementogenesis or by exposing root surface-fibers which by simple fibrogenesis may splint to fibers of the healing surgical wound. Register (1973) and Register and Burdick (1975) have reported accelerated reattachment and cementogenesis when citric acid was applied to surgically created root surfaces. Recently Crigger et al (1978) utilizing citric acid has reported new attachment in surgically created chronic furcation defects in dogs. This study was designed to study the effects of topically applied citric acid in achieving new connective tissue attachment to human teeth involved in chronic periodontal lesions.

Teeth utilized in this study were those scheduled for extractions before the insertion of prosthetic appliances. The experimental teeth met the criteria of having pocket depths of at least six millimeters with clinically demonstrable calculus formation. Ten surfaces of eight anterior teeth and one premolar in six patients were chosen.

When proficiency in oral hygiene was demonstrated, a Widman flap was elevated and a notch was inscribed on the root surface of the tooth. The notch was placed within the calculus formation with the apical extent of the notch placed at the apical extent of the calculus. The root surfaces were thoroughly planed, topically etched with citric acid for five minutes and rinsed. Care was taken to insure primary closure of the flaps. The teeth were allowed to heal for a period of four months and were then removed by block section.

The specimens were analyzed histologicaIIy at 180 M intervals using high and low magnifications to determine: I) the extent of gingival recession, 2) the amount of connective tissue healing, 3) the amount of new cementum formation coronal and apical to the notch, 4) the dimensions of the notch, 5) the apical extent of the junctional epithelium, 6) the distance from the notch to the apical extent of the root. Sections were made longitudinally in a mesial-distaI or buccal-lingual plane dependent on the location of the notch at six micron intervals. The means and standard deviations are given for the sections analyzed.

All sections had new connective tissues including cementum. This new attachment extended a mean of 1.96 ± mm coronal to the apical extent of the reference notch. The sulcus depth was reduced to 1.93 ± mm (mean). new cementum was found 0.87 ± mm (mean) coronal to the reference notch.

The results of this study are exciting: 1) a method has been introduced whereby positive evidence of attachment may be evaluated, 2) evidence of new attachment with and without cementogensis has been demonstrated. Especially interesting are the areas of connective tissue healing without evidence of cementogensis. It is impossible to determine the nature of this healing at the light microscopic level. If acid exposed fibers are able to function in a similar manner as vital connective tissue fibers retained on root surfaces, then it is possible that new cementum formation may no longer be required for new attachment of connective tissues. Indeed, this splicing of fibers exposed during citric acid demineralization has recently been demonstrated by Ririe (1787) in a TEM study in dogs.

Additional TEM studies utilizing citric acid are needed in periodontally involved human teeth. It is important to identify the nature of the connective tissues attachment achieved as this may open a new phase in reconstructive periodontics.

LLU Discipline





Graduate School

First Advisor

Max Z. Crigger

Second Advisor

Jan H. Egelberg

Third Advisor

Robert Kiger

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Periodontal Diseases; Periodontal Prosthesis



Page Count

vi; 58

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website


Loma Linda University. Del E. Webb Memorial Library. University Archives