Long-term maintenance of patients treated for advanced periodontal disease

Periodontal diseases in adult Kenyans

This study comprised 1131 persons who constitute a stratified random sample of the entire population aged 15-65 years in Machakos District, Kenya. Each person was examined for tooth mobility, plaque, calculus, gingival bleeding, loss of attachment and pocket depth on the mesial, buccal, distal and lingual surface of each tooth. The oral hygiene was poor with plaque on 75-95% and calculus on 10-85% of the surfaces depending on age. Irrespective of age, pockets greater than or equal to 4 mm was seen on less than 20% of the surfaces, whereas 10-85% of the surfaces had loss of attachment greater than or equal to 1 mm. The proportion of surfaces per individual with loss of attachment greater than or equal to 4 mm or greater than or equal to 7 mm, and pocket depths greater than or equal to 4 mm or greater than or equal to 7 mm, respectively, showed a pronounced skewed distribution, indicating that in each age group, a subfraction of individuals is responsible for a substantial proportion of the total periodontal breakdown. The individual teeth within the dentition also showed a marked variation in the severity of periodontal breakdown. Our findings provide additional evidence that destructive periodontal disease should not be perceived as an inevitable consequence of gingivitis which ultimately leads to considerable tooth loss. A more specific characterization of the features of periodontal breakdown in those individuals who seem particularly susceptible is therefore warranted.

A longitudinal study comparing scaling, osseous surgery and modified Widman procedures. Results after one year

The purpose of this study was to compare, longitudinally, the effectiveness of scaling and root planing, osseous surgery, and the modified Widman procedures. The study was carried out in a private practice setting. Sixteen adult patients with moderate to advanced adult periodontitis were treated with initial scaling and oral hygiene procedures. Posthygiene data were used for comparison of changes in probing depth, clinical attachment levels and gingival recession. The initial examination data were used to compare changes in plaque and gingival indices. Frequency distributions were used to compare changes that occurred at individual sites. At one year, plaque and gingival indices were significantly reduced when compared with the initial examination. At one year, shallow pockets (1-3 mm) were reduced when compared to posthygiene. Four- to six-millimeter pockets were significantly reduced by the three procedures. Osseous surgery and modified Widman had significantly greater pocket reduction when compared with scaling. For pockets greater than 7 mm, osseous surgery and the modified Widman had significantly greater reduction when compared with scaling. For pockets 1-3 mm at one year osseous surgery had significantly greater clinical attachment loss when compared with scaling. For 4-6 mm pockets at one year, the three procedures had slight gains in clinical attachment levels. The results were similar for pockets with greater than 7 mm. Interproximal soft tissue craters were measured for six postoperative weeks. Initially, the modified Widman had a higher percentage of soft tissue craters when compared with osseous surgery. At six weeks, however, there were no significant differences when the surgical procedures were compared. Recession was measured at each examination. Recession for 1-3 mm pockets at one year was greater for osseous surgery when compared with scaling and the modified Widman. Recession for 4-6 mm and greater than 7 pockets was greater for the surgical procedures than scaling. The results from this study indicate that with three-month maintenance recalls, both the modified Widman and osseous surgery are effective for pocket reduction, and each will produce a slight gain of clinical attachment over one year. Scaling was effective at maintaining attachment levels but was not as effective in reducing pocket depth.

Tooth loss in 1535 treated periodontal patients

Of 1535 treated recall patients surveyed over an average time of 12.9 years since treatment was completed, 1371 had lost no teeth from periodontal disease. The total number of teeth lost was 444, with the average tooth loss for the 1535 patients being 0.29. In the three full arch splinted cases, the loss rate was 14.67 teeth per patient. Patients treated without any excisional or flap surgical procedures made up 26.5% of those surveyed, whereas 73.5% had required various surgical procedures. No attempt was made to compare different pocket therapy procedures. Although many patients developed recurrent periodontal problems during recall, only 15.9% of the 1535 patients required surgical retreatment. Teeth that were originally given a doubtful prognosis often were responsible for recurrent problems and sometimes required extraction.

The angular bony defect in the maintenance of the periodontal patient

The present retrospective study was performed to evaluate some long-term alterations of the alveolar bone level at periodontal sites with angular and even ("horizontal") patterns of bone loss. The investigation included 48 patients who, following treatment for advanced periodontal disease, were placed in a maintenance care program which included recall appointments every 3-6 months for a period of 5 to 16 years. The material of the study comprised all teeth at which angular osseous defects (test sites) could be detected in a full-mouth series of radiographs obtained at the end of the active treatment phase. Alterations in the position of the marginal alveolar bone crest and the base of the osseous defect which took place during the maintenance period were assessed by comparing the post-treatment radiographs with a 2nd set of radiographs obtained at the final examination. In the same patients, an equal number of contralateral or neighboring teeth at which bone loss in the radiographs had an even or "horizontal" character were included as controls. The results from the assessments demonstrated that periodontal sites which, following active therapy displayed either angular or "horizontal" patterns of alveolar bone loss underwent, during a 5-16 year period of maintenance, only minor bone level alterations. Additional loss of supporting bone occurred equally frequently at sites with "horizontal" and angular patterns of bone loss. Thus, the findings reported failed to show up sites with angular bony defects as being particularly susceptible to recurrent destructive periodontitis.

The effect of orthodontic treatment on periodontal bone support in patients with advanced loss of marginal periodontium

Loss of periodontal bone support was examined in 24 patients orthodontically treated for pathologic tooth migration in one jaw. Prior to orthodontic realignment of the front teeth, the patients had received periodontal treatment. Active appliance therapy was not given until inflammation was eliminated and the patients demonstrated a high level of oral hygiene. A 0.020-inch spiral wire was bonded to each adjacent realigned tooth for retention. The levels of marginal bone of the front teeth in the treated and untreated jaws were measured in percentage of "maximum bone height" on periapical radiographs made before and after treatment. Relapse was evaluated from study models. Mean averaged loss of periodontal bone from the period before to after orthodontic treatment was 4.94% (SD 4.03, P less than 0.001) and 2.69% (SD 3.66, P less than 0.001) of the treated and untreated front teeth, respectively. The mean difference in averaged loss between treated and untreated front teeth was 2.24% (SD 3.28, P less than 0.01). The majority of the sites showed little or no loss. Maximum loss (35%) was observed in one site only. No association was found between initial bone loss and bone loss during orthodontic treatment. Spaces from 0.1 to 1.8 mm opened up adjacent to the retainer in seven patients. Relapse within the retained segment was associated with failures of the retainer. Of the 19 patients who had been in retention for more than 4 months (mean 16.0, SD 12.1), ten failures were recorded in nine patients. The failure mode was loosening of one or two teeth between wire and composite.

Long-term periodontal status after orthodontic treatment

This study evaluated the clinical periodontal status of persons who had completed orthodontic therapy at least 10 years previously (study) and compared the findings to those of adults with untreated malocclusions (control). Subjects in the study (n = 112; 63 female subjects, 49 male subjects; mean age 29.3 +/- 4.2 [SD] years) and control (n = 111; 62 female subjects, 49 male subjects; mean age 32.9 +/- 6.5 years) populations underwent a comprehensive periodontal examination that consisted of measurements taken at six points around the circumference of each tooth: (1) plaque, (2) visual inflammation, (3) bleeding after probing, (4) pocket depth, (5) gingival recession, and (6) loss of connective tissue attachment. Data from the individual measuring points were organized into 14 different combinations of either tooth types or surface locations; each was subjected to a four-way ANOVA partitioned on group (study vs. control), sex, socioeconomic status, and malocclusion type. The results showed that differences in age distribution within the groups were affecting the comparisons between the groups. Consequently, the groups were balanced for age and analyses were done to investigate group differences by means of multiple regression techniques. The comparisons showed no significant differences between the groups for any of the periodontal variables. It was concluded that orthodontic treatment during adolescence had no discernible effect upon later periodontal health.

Compliance. A review of the literature with possible applications to periodontics

This paper begins with a review of the literature on compliance. The medical literature suggests that patients with chronic illnesses tend to comply poorly, especially if the disease is not perceived by the patient as particularly threatening. The dental literature covers two principal areas: compliance with oral hygiene regimens and utilization of dental care by the public. These works show that most patients surveyed do not clean their teeth as they have been instructed, and most do not receive routine dental care. The reasons for this noncompliance are highly variable but include lack of pertinent information, fear, economics, and the patient's perception of lack of compassion on the part of the dental therapist. In periodontics the majority of studies have focused on the effectiveness of patient oral hygiene along with its modification and on maintenance therapy. Other work in the periodontal literature is discussed in light of the widespread noncompliance shown by our patients. A number of studies have been undertaken on how best to improve compliance. In general, it has been found that patients comply better when they are informed and positively reinforced, and when barriers to treatment are reduced. Suggestions are made for improving compliance in the periodontal office and for tailoring therapy to predicted compliance levels.

Maintenance care for treated periodontitis patients

This paper is a review of current literature combined with clinical observations. Well-controlled maintenance care is a key consideration in the long-term prognosis of treated periodontitis patients. Periodic professional tooth cleaning every 3 to 4 months often is recommended. Furthermore, recent studies indicate a potential need for selected retreatment in problem areas, since minute residual accretions may be left behind during active therapy--even with "open" surgery. While efficient plaque control is essential for optimal results during the healing phase of periodontal therapy, periodic prophylaxis may prevent loss of clinical attachment over long periods of time even for patients with less than perfect oral hygiene.

4 modalities of periodontal treatment compared over 5 years

The purpose of the present study was to assess in a clinical trial over 5 years the results following 4 different modalities of periodontal therapy (pocket elimination or reduction surgery, modified Widman flap surgery, subgingival curettage, and scaling and rool planing). 90 patients were treated. The treatment methods were applied on a random basis to each of the 4 quadrants of the dentition. The patients were given professional tooth cleaning and oral hygiene instructions every 3 months. Pocket depth and attachment levels were scored once a year. 72 patients completed the 5 years of observation. Both patient means for pocket depth and attachment level as well as % distribution of sites with loss of attachment greater than or equal to 2 mm and greater than or equal to 3 mm were compared. For 1-3 mm probing depth, scaling and root planing, as well as subgingival curettage led to significantly less attachment loss than pocket elimination and modified Widman flap surgery. For 4-6 mm pockets, scaling and root planing and curettage had better attachment results than pocket elimination surgery. For the 7-12 mm pockets, there was no statistically significant difference among the results following the various procedures.

Tissue localization of Actinobacillus actinomycetemcomitans in human periodontitis. II. Correlation between immunofluorescence and culture techniques

Recent immunohistological studies have suggested that Actinobacillus actinomycetemcomitans is present in the gingival tissues in juvenile periodontitis lesions. The present study examined tissue bound A. actinomycetemcomitans by bacterial culture and immunohistological demonstration of antigen in tissue. A total of 14 periodontitis lesions were examined. Eleven biopsies were obtained from gingiva adjacent to A. actinomycetemcomitans infected pockets, while the remaining three control biopsies were obtained from gingiva adjacent to pockets where subgingival A. actinomycetemcomitans infection could not be detected. Each biopsy was hemisected, one half was used for immunofluorescence microscopic examination while the other half was processed for culture of A. actinomycetemcomitans. The latter section was surface-disinfected, repeatedly washed and then minced to release bacteria from within the tissues. Aliquots from the serial washings and the minced tissue suspension were cultured on medium selective for A. actinomycetemcomitans. Surface disinfection and serial washings gradually decreased cultivable A. actinomycetemcomitans in the washings aliquots. Following tissue disruption, an increase in colony-forming units of A. actinomycetemcomitans was seen from eight of the 11 test biopsies. This bacterium could not be detected in washings or minced tissue suspensions from the control biopsies obtained from lesions in which subgingival A. actinomycetemcomitans was previously not detected. A positive correlation was seen between the presence of A. actinomycetemcomitans antigens in the gingival biopsies and; (1) A. actinomycetemcomitans colony-forming units released from the minced tissues (r = 0.90, p = 0.000), as well as; (2) the colony-forming units from the periodontal pocket (r = 0.62, P = 0.017).(ABSTRACT TRUNCATED AT 250 WORDS)

Tissue localization of Actinobacillus actinomycetemcomitans in human periodontitis. I. Light, immunofluorescence and electron microscopic studies

Invasion of periodontal tissues by different bacterial morphotypes has been reported in human periodontitis; however, limited information is available as to prevalence, localization and the bacterial species involved. The present study determined prevalence and gingival localization of Actinobacillus (Haemophilus) actinomycetemcomitans in periodontal lesions of juvenile periodontitis patients. Thirty-five gingival biopsies were obtained from 12 juvenile periodontitis patients at the time of periodontal therapy. One additional control biopsy was obtained from each of two adult periodontally healthy subjects, one adult periodontitis patient and one periodontally healthy monkey (Macaca fosibolius). The biopsies were carefully processed to avoid mechanical introduction of bacteria into the tissues and were examined using light and electron microscopy. Rabbit antisera specific for the three A. actinomycetemcomitans serotypes were used for immunofluorescence microscopic localization of A. actinomycetemcomitans antigens in the gingival sections. Immunofluorescence microscopy showed A. actinomycetemcomitans specific antigens in the gingival tissues of 11 of the 12 juvenile patients examined. None of the control specimens showed evidence of A. actinomycetemcomitans antigens in the gingival connective tissue. One specimen from a periodontally healthy subject and the monkey biopsy, however, showed A. actinomycetemcomitans antigens in bacterial plaque on the surface of the crevicular epithelium. Transmission electron microscopic examination showed microcolonies of small gram-negative rods in the connective tissue, as well as single bacterial cells between collagen fibers and in areas of cell debris. In addition to these extracellular bacterial cells, evidence of bacterial cells was also found within gingival connective tissue phagocytic cells. The data from the present study suggest that the gingival tissue in juvenile periodontitis lesions harbors A. actinomycetemcomitans.

Long-term effect of root proximity on periodontal health after orthodontic treatment

The present investigation was done to evaluate the incidence and distribution of root proximity after orthodontic treatment and to test the hypothesis that interproximal areas with thin interdental bone provide less resistance against marginal periodontal breakdown than areas with normal width of bone between the roots. Only adult patients were examined at least 16 years after active orthodontic treatment. The distance between the roots was measured directly on periapical radiographs. Gingival health, level of connective tissue attachment, and clinical scores for bone levels in sites with thin interdental bone and neighboring or contralateral sites with normal width of bone between the roots were compared. Among the 400 patients studied, 25 had unilateral or bilateral areas with root proximity. Root proximity was diagnosed between maxillary central and lateral incisors in 18 patients, between mandibular central and lateral incisors in two patients, and between maxillary lateral incisor and canine, maxillary first and second molars, mandibular canine and first premolar, mandibular first and second premolars, or mandibular first and second molars in only one patient. No statistically significant differences in inflammation, level of attachment, and bone level were observed between root proximity sites and control sites. The results indicate that anterior teeth are not predisposed to more rapid periodontal breakdown when roots are in close proximity. Too few molar sites were included to draw conclusions regarding such areas.

Periodontal status of teeth facing extraction sites long-term after orthodontic treatment

The present study was undertaken to examine the long-term periodontal status of teeth orthodontically moved into extraction sites. Patients were examined 14 to 34 years after active orthodontic treatment involving extraction of four first premolars. Three groups were established: one with closed tooth contacts and parallel adjacent teeth, one with closed tooth contacts and tipped adjacent teeth, and one with open contacts between adjacent teeth. Within each group accumulation of plaque, gingival health status, probing pocket depth, and probing attachment level of interproximal tooth surfaces, facing extraction sites and adjacent control sites between canine and lateral incisor were compared. Significantly more probing attachment loss was found in extraction sites with open tooth contacts (P less than 0.01) and with parallel adjacent teeth and closed tooth contacts (P less than 0.05) than in control sites. However, the mean differences were less than 0.5 mm, which may not be considered clinically significant. Tipping of teeth into the extraction sites had no long-term detrimental effect on the probing attachment level. No differences in accumulation of plaque and in gingival health status were observed.

Is periodontal disease the primary cause of tooth extraction in adults?

Preventing caries and reducing out-of-pocket costs for dental services are two strategies proposed by the authors to lower the rate of tooth extractions. Efforts also must be made to change public values about the importance of restoring rather than extracting carious teeth.

The non-specific theory in microbial etiology of inflammatory periodontal diseases

In the absence of toothbrushing, the gingival crevice is colonized by a complex indigenous microflora causing gingivitis, a non-specific inflammation. Subgingival plaque may develop by downgrowth into the inflamed pocket of those micro-organisms from supragingival plaque which can multiply there. By direct microscopy, increased proportions of motile rods and spirochetes have been found in diseased pockets. Cultures on selective media have demonstrated increased prevalence of various gram-negative rods. Cultures on non-selective media have revealed the complexity and variability of the subgingival microflora, comprising more than 200 species. Destructive periodontitis is the result of subgingival colonization, which is favored by such ecological changes as plaque accumulation, gingivitis, and gingival exudate. These changes increase the numbers of micro-organisms and alter their proportions, but no single species appears in active sites which is not also commonly present in inactive sites. The subgingival micro-organisms have several virulence factors which promote colonization of the pockets, destroy host defense mechanisms, and provoke inflammation. It appears that different combinations of indigenous bacteria, rather than just a single species, can produce the pathogenic potential necessary to cause progression from gingivitis to destructive periodontitis.

Comparative longitudinal study of 2 methods of scheduling maintenance visits; 2-year data

This report compares the clinical and microbiological status of 2 groups of subjects with treated periodontis on different maintenance schedules. 43 control (C) subjects were given prophylaxes every 3 months. 40 test (T) subjects were given this service on a flexible schedule according to the proportions of spirochetes and/or motile rods in fresh smears of subgingival scrapings. Both groups were examined every 6 months clinically and microbiologically. This report presents base line, 1- and 2-year data. Generally, mean values for both groups did not differ significantly from one another. Both groups exhibited comparable increases in GI and PLI scores during the first 2 years of this study. No change in probing depth was noted between base line and the 2-year examination. However, a slight increase in attachment level, as determined by probing, was noted in both groups. Both groups also exhibited similar proportions of bacterial morphotypes at base line and subsequent examinations. Disease recurrence, defined as an increase in probing depth of 3 mm or more from base line on any tooth surface during the 2-year period, tended to be more prevalent in the C than in the T group (15/43 C and 9/40 T subjects). However, the proportional difference between the groups was not statistically significant. Subjects with disease recurrence in the T group had greater proportions of spirochetes at base line than subjects in the same group without disease recurrence (20.2% versus 9.8%, p less than 0.01). This difference in proportions persisted if both groups were examined jointly, but was only of borderline significance (16.0% versus 10.5%, p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Bleeding on probing. A predictor for the progression of periodontal disease?

Bleeding on probing (BOP) is a widely used criterion to diagnose gingival inflammation. The purpose of the present retrospective study was to evaluate its prognostic value in identifying sites at risk for periodontal breakdown during the maintenance phase of periodontal therapy. 55 patients who had been treated for advanced periodontitis participated in a recall system for at least 4 years, at regular intervals of 3-5 months. At the start of every appointment, BOP to the bottom of the pocket was registered at 4 sites of every tooth. A random selection of 1054 pockets was made and subdivided into 5 categories according to the incidence of BOP during the last 4 recall appointments. All pockets with a BOP incidence of 4/4 and 3/4 were selected, while only interproximal sites with a BOP incidence of 2/4, 1/4 and 0/4 were chosen. Subsequently, these categories were grouped according to whether or not the attachment level had been maintained from the time prior to the last 4 recall visits. Greater than or equal to 2 mm was defined as loss of clinical attachment. The results indicated that pockets with a probing depth of greater than or equal to 5 mm had a significantly higher incidence of BOP. Patients with 16% or more BOP sites had a higher chance of loosing attachment. Pockets with an incidence of BOP of 4/4 had a 30% chance of loosing attachment. This chance decreased to 14% with BOP of 3/4, 6% with BOP of 2/4, 3% with BOP of 1/4 and 1.5% with BOP of 0/4.(ABSTRACT TRUNCATED AT 250 WORDS)

The condition of the soft tissues at tooth and fixture abutments supporting fixed bridges. A microbiological and histological study

In 10 partially edentulous patients provided with fixed bridgework supported by the combination of tooth and titanium fixture abutments, the condition of the soft tissues surrounding the abutments was examined. Sampling of supra- and subgingival plaque was performed from both teeth and fixtures. The samples were analyzed regarding the total bacterial counts, the relative distribution of bacterial morphotypes and the cultivable microflora. From each patient, soft tissue biopsies were obtained from 1 tooth and 1 fixture abutment, and the specimens were analyzed for the presence and extension of inflammatory cell infiltrates. The microbiological examination showed that the distribution of bacterial morphotypes in the supra- and subgingival plaque both at teeth and fixtures were similar, irrespective of localization and type of abutment. Nonmotile rods dominated the microflora, whereas spirochetes were either not detected or occurred in very low proportions. From the histological analysis, it was found that a majority of the soft tissue biopsies (75-80%) from both tooth and fixture sites contained only very small inflammatory cell infiltrates.

Bone loss following periodontal therapy in subjects without frequent periodontal maintenance

The longitudinal effects of periodontal therapy in patients without a frequent periodontal maintenance program have been minimally documented. In this study we used Duckworth's modification of the Schei Ruler Technique to assess the difference in bone level around individual teeth treated for periodontal disease in subjects receiving infrequent posttherapy maintenance (less than or equal to 1 time/year). Crestal bone height differences were evaluated using the initial presenting series of long cone parallel radiographs of 23 subjects with their subsequent posttherapy analogous radiographic series taken 5.4 +/- 2.9 years later. Bone loss was defined as a reduction in the alveolar crest of greater than 50% of the radiographic crown height which corresponds to approximately 4 mm in posterior and 5 mm in anterior teeth. The loss for each tooth was expressed as a per cent of the measured height of the crown after conversion from millimeters using the mean crown-root ratio for each tooth. We found increased alveolar bone loss and tooth loss in subjects examined posttherapy when compared with conditions present when each subject initially presented for periodontal treatment. Our data suggest that molar teeth are more at risk than incisors and cuspids and that a lack of periodontal maintenance care and inadequate plaque control contribute to progressive bone loss following treatment.

Effect of periodontal therapy on patients maintained for 15 years or longer. A retrospective study

A retrospective study of tooth loss in 211 patients who were treated for periodontal disease in private practice and maintained for 15 to 34 years on 3- to 6-month recall schedules is reported. The average age of the patients was 42 years, and the average length of time in maintenance was 22 years. On the basis of response to therapy, the patients were classified as Well-Maintained (62%), Downhill (28%) and Extreme Downhill (10%). Seven hundred and seventy-one (771) teeth were lost (13.4%) due to all causes. Molar teeth are the most prone to loss and the mandibular cuspid is the most resistant. The importance of maintenance therapy is emphasized.

Long-term effect of thin interdental alveolar bone on periodontal health after orthodontic treatment

The present experiment was undertaken to determine if an interproximal area with a thin interdental bone septum following orthodontic treatment provides less resistance against marginal periodontal breakdown than an interproximal area with a normal width of bone between the roots. Only adult patients, at least 16 years after active orthodontic treatment, were studied. The distance between the roots was measured directly on periapical radiographs. Gingival health, level of attachment and bone level in sites with thin interdental bone were compared with neighboring or contralateral sites with a normal width of bone between the roots. No statistically significant differences in inflammation, level of attachment and clinical scores for bone level were observed. When measured radiographically the distance from the cementoenamel junction to the alveolar bone was significantly shorter in neighboring control sites (P less than 0.05). This discrepancy was most likely due to radiographic distortion. The results of this investigation suggest that in anterior areas marginal periodontal breakdown is unrelated to the thickness of bone between the roots. Too few molar sites were included to draw conclusions regarding such areas.

Design of clinical trials of traditional therapies of periodontitis

The present paper on the design of clinical trials of periodontal therapy first addresses the issue of the etiology of periodontal disease. It is suggested that most if not all forms of destructive periodontal disease are caused by microorganisms and that there are different forms of disease with different microbial etiologies. The progressive nature of destructive periodontal disease is subsequently discussed and it is emphasized that, in a given patient, periodontal sites which show signs of inflammation and attachment loss may not over a period of several months and years show further sign of attachment loss. The present methods of assessing periodontal disease do not allow us to discriminate between potentially active and inactive sites in untreated patients. The significance and variability of indicators of periodontal disease such as bleeding on probing, probing pocket depth and probing attachment level measurements are discussed. The errors inherent in the various measurements are analyzed and suggestions are presented describing how alterations in any of the above parameters could be identified and presented in a clinical trial. Of concern for the statistical analysis of clinical data of periodontal disease is the definition of the "experimental unit". For a number of years, the "experimental unit" in periodontal trials was the patient. It is clear, however, that different sites within the same individual show different patterns of disease progression and lesion morphology and often respond differently to periodontal therapy. Statistical analyses must consequently be designed which recognize differences in site-to-site infection and lesion morphology within a common host. Until such analyses are available, the investigator should be wary of pooling data within the same individual, since such pooling may obscure meaningful alternatives which may take place in individual periodontal sites. Some goals of periodontal therapy are subsequently identified. 4 goals are discussed more in detail, namely: to establish conditions which will allow the patient to maintain a dentition without further breakdown of the periodontium; to reduce pocket depth to establish an anatomy in the dentogingival region which with proper maintainance care will prevent the re-establishment of the subgingival infection; to gain attachment as a result of treatment; to assess the effect of a certain chemotherapeutic agent on periodontal disease.

Pathogenesis of periodontitis

Periodontitis is an inflammatory disease of the periodontium which is characterized by a progressive destruction of the tissues supporting the tooth. Its primary etiology is an ill-defined series of microbial infections which may be composed of only some of the more than 300 species of bacteria currently recognized in the oral cavity. The disease is currently considered to progress as periodic, relatively short episodes of rapid tissue destruction followed by some repair, and prolonged intervening periods of disease remission. Despite the apparent random distribution of episodes of disease activity, the resulting tissue breakdown exhibits a symmetrical pattern of alveolar bone loss and pocket formation which is common to several forms of periodontitis, although the distribution of the most affected teeth and surfaces may vary among diseases (e.g., juvenile periodontitis versus adult periodontitis or rapidly progressive periodontitis). Several reports have indicated that bacterial cells can be found in the pocket wall of periodontitis lesions. The translocation of bacteria into the tissues from the pocket environment is quite common, as evidenced by the common occurrence of bacteremias in patients with periodontitis following relatively minor events such as chewing and oral hygiene procedures. However, it is important to distinguish between the passive introduction of bacteria into periodontal tissues and frank invasion as might occur in an acute infection, since the pathological implications may be quite different.

Lack of effect of citric acid treatment of root surfaces on the formation of new connective tissue attachment

Previous reports have described an accelerated induction of new attachment and repair of furcations in dogs after treatment of roots surfaces with citric acid, but few controlled clinical studies have examined its usefulness in surgical treatments for periodontitis. This study compared the effects of a comprehensive surgical plaque control procedure with or without citric acid treatment for generalized and localized effects on gingival height, probing pocket depth and attachment level in 72 teeth in 3 patients who were treated surgically for moderate periodontitis and examined every 3 months for 1 year. No statistically significant differences in the effects of the 2 treatments were observed. These observations suggest that there is no clinical advantage of citric acid conditioning of the root surface during surgical treatment of periodontitis.

Effect of age on healing following periodontal therapy

The present investigation was performed in order to analyze the effect of age on healing of the periodontal tissues following treatment. The patients included in the present analysis consisted of 2 different samples. One group of 62 patients (sample A) was examined and treated between 1980 and 1982. 13 of these subjects were less than 40 years of age, 26 subjects were 40-49 years of age and 23 subjects were greater than 49 years old. The patients were subjected to periodontal surgery using the modified Widman flap procedure. During the active phase of treatment and for the subsequent 6 months of healing, all 62 patients were subjected to professional tooth cleaning. Instruction in proper oral hygiene measures was repeated and scaling was carried out when indicated. Sample B consisted of 21 subjects treated for advanced periodontal disease in 1969. Six of these patients were between 26 and 29 years of age at the start of treatment and 15 were at least 60 years old. The criterion for acceptance for the study in 1969 was that the patient should have lost 50% or more of his/her periodontal tissues. Following an initial examination, all patients were subjected to scaling and root planing and surgical elimination of pathologically deepened pockets. After the termination of active treatment, the patients were placed in a maintenance care program which included recall appointments every 3-6 months. Once a year after the completion of active treatment, all patients in this sample were examined regarding probing depths and clinical attachment levels. The findings from the present retrospective analyses failed to demonstrate that the age of patients with moderately advanced or advanced forms of periodontal tissue breakdown had an influence on the results of periodontal therapy. If anything, the younger patients appeared to heal with a higher frequency of shallow pockets and more gain of probing attachment than older patients.

Improved periodontal conditions following therapy

The aim of the present clinical trial was to evaluate the effect of different modes of periodontal therapy on patients with moderately advanced periodontal disease and to express the findings in terms of probing pocket depth and attachment level alterations at periodontal sites with different initial probing depths. The material consisted of 16 patients, 35-65 years of age. Following a Baseline examination including assessments of oral hygiene status, gingival conditions, probing pocket depths and probing attachment levels, the patients were subjected to periodontal treatment. A "split-mouth" design approach of therapy was used and the jaw quadrants were randomly selected for the following different treatment procedures: (1) scaling and root planning, (2) scaling and root planing in conjunction with a gingivectomy procedure, (3) scaling and root planing in conjunction with an apically repositioned flap procedure without bone recontouring, (4) scaling and root planing in conjunction with an apically repositioned flap procedure including bone recontouring, (5) scaling and root planing in conjunction with a modified Widman flap procedure without bone recontouring and (6) scaling and root planing in conjunction with a modified Widman flap procedure including bone recontouring. The patients were following active treatment enrolled in a supervised maintenance care program including "professional tooth cleaning" once every 2 weeks during a 6-month period of healing, after which a final examination was performed. The investigation demonstrated that active therapy including meticulous subgingival debridement resulted in a low frequency of gingival sites which bled on probing, a high frequency of sites with shallow pockets (less than 4 mm) and the disappearance of pockets with a probing depth of greater than 6 mm. Between the Baseline examination and the 6-month re-examination, the probing attachment level for initially shallow pockets remained basically unaltered, but with a tendency of a minor apical shift. This occurred in all 6 treatment groups. For sites with initial probing depths of 4-6 mm and greater than 6 mm, there was in all groups some gain of probing attachment. This gain was most pronounced in the initially deeper (greater than 6 mm) pockets. With the use of regression analysis, the "critical probing depth" (CPD) value (i.e. the initial probing depth value below which loss of attachment occurred as a result of treatment and above which gain of probing attachment level resulted) was calculated for each of the 6 methods of treatment used. A comparison of the CPD-values between the 6 treatment groups did not reveal any major differences.

3-year longitudinal study of the periodontal status of an adult population with gingivitis

69 adults ranging in age from 20 to 73 (mean age: 37) were randomly assigned to a control (C) and a test (T) group. Of these, 61 completed the 3-year longitudinal study. All subjects had varying degrees of gingivitis at the start, but no overt periodontitis. Following a base line examination for P1I, GI, probing depth (PD) and recession, a differential darkfield microscopic (DDFM) count of subgingival bacterial morphotypes was carried out on a pooled sample originating from one tooth surface in each sextant with the greatest probing depth. Examinations were repeated every 6 months for 3 years. The C group received regular prophylaxes every 6 months. The T subjects received prophylaxes according to a previously described schedule, and on the basis of the DDFM test outcome. Recall intervals at the end of the study for the T group ranged from 1 to 24 months (mean: 15.7 months). Of 30 subjects in the T group at the end of the study, one half had not had their teeth cleaned for periods of 18 to 36 months without any detectable deterioration in their periodontal status by comparison with the other T subjects or the patients in the C group. Both C and T subjects exhibited increased mean P1I and GI scores as compared to base line during the first half of the study. However, mean PD measurements remained unchanged. Increases in PD from base line of 3 mm or more were observed only in approximately 1 out of a 1000 individual tooth surface comparisons, a frequency comparable to that expected to occur by chance alone. This observation indicates that in this population, little if any pocket formation occurred during the study period. GI score increases of 2 units or more occurred in relatively few subjects. 2 of 31 C patients accounted for 42% of the affected dental units, while 5 out of 30 T subjects accounted for 40.8% of the affected dental units in that group. These observations suggest that despite the relatively high prevalence and incidence of gingivitis, the subjects were relatively resistant to periodontitis. Neither preventive schedule was effective in eliminating gingivitis. The lack of significant destructive disease in this population prevented any meaningful comparison of the relative effectiveness of the two preventive maintenance regimens in preventing recurrences of periodontitis.