This paper describes: (1) a system for classification and treatment of furcation involvements, and (2) a 5-year post-operative evaluation of 100 patients treated for periodontal breakdown in the bi/tri-function areas. The results of this study demonstrate that it is possible to arrest further destruction within the root furcation area. The successful treatment of the multirooted teeth was probably the consequence of: (1) the quasi total elimination of plaque retention areas from the bi/tri-furcation area, and (2) meticulous oral hygiene by the patients.

The purpose of the present investigation was to study the sequential stages in the development of a periodontal lesion starting from a healthy periodontium. Twenty inbred Beagle dogs 10 months of age and weighing 10–12 kilos were used. The animals were equally divided into one experimental and one control group. Throughout the experiment all dogs were given a diet containing 400 gm pellets and 25 gm soya flower. From day zero the teeth (in the left jaws) of the control dogs were twice dally subjected to a careful but gentle brushing with tooth brush and dentifrice. The teeth of the experimental group animals were not cleaned. The dogs were examined at regular intervals during an 18 month period. The results show that it is possible in young dogs to induce gingivitis which gradually develops into periodontitis simply by allowing plaque to accumulate on teeth. The cleaned teeth did not show signs of gingivitis or periodontitis during the entire experiment. It is proposed that in the Beagle dog the progression of the lesion during an 18 month period may occur in three stages: I) subclinical gingivitis, II) clinical gingivitis and III) periodontal breakdown. Subclinical gingivitis was characterized by a rapidly increasing gingival exudation and migration of crevicular leukocytes, i. e. signs off acute inflammation. Clinical gingivitis was characterized by changes in gingival colour, texture and bleeding tendency but only minor alterations of the number of crevicular leukocytes. Periodontal breakdown, characterized by loss of subgingival fiber attachment, occurred only in areas of clinical gingivitis.

The type and frequency of dental diseases and disorders were determined in 162 randomly selected dogs available for necropsy. There were 82 males and 80 females ranging in age from seven months to 14 years. There were 150 purebred dogs (50 different breeds) and 12 mongrels. Only four breeds were represented by ten individuals or more: Poodles (Miniature and Toy), German Shepherds, Dachshunds, and Boxers. The oral cavity was examined macroscopically, and missing teeth, dental caries, dental calculus (tartar), and gingival epulides were recorded as to frequency and distribution. After macroscopic examination of the oral cavity, the head of each dog was sawed at the midline, fixed in formalin, and radiographed. The frequency, severity, and distribution of marginal periodontitis, periapical destruction, and root resorption were recorded. The most frequently noted disease was periodontitis, which increased in frequency and severity with increasing age of the dogs. The disease varied markedly among and within different breeds. Small dogs were more often affected with periodontitis than large dogs. Periapical destruction was a common finding. Caries and root resorption were less common. Missing teeth was a frequent disorder regardless of age. Most of the dogs had dental calculus.

Caries development on exposed root surfaces was evaluated in 31 patients who had been subjected to surgical and/or nonsurgical periodontal treatment 8 years earlier due to advanced chronic periodontitis. Besides assessments for evaluation of the periodontal treatment, a number of examinations and tests were carried out in order to assess variables presumed to influence the root surface caries development. Both statistical and graphical analyses were carried out to test differences between groups of subjects and to evaluate the variables studied as possible risk factors for root surface caries. The variables studied were: salivary lactobacillus count, salivary Streptococcus mutans count, plaque score, salivary secretion rate, salivary buffer effect, oral sugar clearance time, dietary habits and the age of the subject. The final results support previous findings from an initial 4-year period that root surface caries occurs, though to a minor extent, in this patient category demonstrating good or excellent periodontal conditions after periodontal treatment. A positive correlation was found between the baseline and final root surface caries scores. After the second 4-year period, the salivary counts of S. mutans and lactobacilli, the plaque score and the dietary habits differed significantly between groups of subjects who had developed 0 or greater than 5 new DFS %. Root surface caries was far more prevalent when risk values of the variables studied were present than when they were absent. The important variables in this respect differed considerably between the subjects. No single variable was found to be discriminative in all subjects.

The present investigation was undertaken (1) to analyze the prevalence of root surface caries prior to and after periodontal treatment and (2) to determine the feasibility of using simple clinical criteria for predicting a patient's risk of developing root surface caries following periodontal therapy. Thirty-one patients were given advanced periodontal treatment including periodontal surgery. At baseline they were examined for oral hygiene status, root surface caries experience and number of lactobacilli per ml saliva as evaluated by the Dentocult dip-slide method. Follow-up examinations 1, 2 and 4 years after baseline showed that a majority of the patients were treated successfully and maintained in periodontal health. Root surface caries developed in approximately two-thirds of the patients during the 4-year observation period. However, the total increment of root lesions during these years was mostly extremely low, i.e. less than 5% of exposed root surfaces. In higher risk patients developing new root surface caries, significant correlations were demonstrated with initial pretreatment scorings from (1) their previous root surface caries experience, (2) high lactobacillus counts and (3) advancing age. In addition, root surface caries incidence and low saliva secretion rats were found to correlate significantly during the course of the study.