Subgingival Deposits Research Articles

ROOT INSTRUMENTATION: Power-Driven Versus Manual Scalers, Which One?

The literature is clear that periodontal therapies aimed at altering the progression of inflammatory periodontal diseases must include meticulous subgingival mechanical débridement during both the nonsurgical and the surgical phases of treatment as the basis of most anti-infective therapy. In the past, infection control was achieved by the mechanical removal of subgingival deposits of plaque, calculus, and endotoxin with curets, files, and hoes. Historically, it was also generally agreed that aggressive scaling and root planing with hand instruments was necessary to remove tenacious calculus deposits to produce roots as smooth as possible for removal of the endotoxins previously thought to be deeply embedded into the root surfaces. Based on current evidence in the literature, it is now known that endotoxin is a weakly adherent surface phenomenon and that sonic and ultrasonic (power-driven) instruments can be used to accomplish definitive root detoxification and maximal wound healing without overinstrumentation of root and without extensive cementum removal. Power-driven scalers may have unique advantages because of the cavitational activity associated with ultrasonics thought to supplement removal of root surface plaques. In addition, the constant flushing activity of the lavage used to cool the tips results in disruption of the unattached and weakly attached subgingival plaques. 58, 59 The ability to flush the pocket during subgingival instrumentation with water or other chemical irrigating solutions is unique to ultrasonic and sonic scalers and has been shown to enhance pocket depth reduction and gain in clinical attachment beyond that achieved with hand scaling. 10, 24, 45 The added benefit of chemical lavage during ultrasonic instrumentation shows great promise and may enhance the overall effect of nonsurgical anti-infective periodontal therapy. Other major advantages of power-driven scalers may include better access to difficult areas, such as deep narrow defects, root grooves, and furcations, using newly designed microultrasonic tips, which are smaller in diameter and able to penetrate the pocket approximately 1 mm farther than hand instruments. 16, 53 Taken together, it appears that use of ultrasonic or sonic scalers for periodontal debridement will result in improvements in clinical and microbial parameters at a level equal to or superior to hand scalers.

Dental calculus: recent insights into occurrence, formation, prevention, removal and oral health effects of supragingival and subgingival deposits.

Dental calculus, both supra- and subgingival occurs in the majority of adults worldwide. Dental calculus is calcified dental plaque, composed primarily of calcium phosphate mineral salts deposited between and within remnants of formerly viable microorganisms. A viable dental plaque covers mineralized calculus deposits. Levels of calculus and location of formation are population specific and are affected by oral hygiene habits, access to professional care, diet, age, ethnic origin, time since last dental cleaning, systemic disease and the use of prescription medications. In populations that practice regular oral hygiene and with access to regular professional care, supragingival dental calculus formation is restricted to tooth surfaces adjacent to the salivary ducts. Levels of supragingival calculus in these populations is minor and the calculus has little if any impact on oral-health. Subgingival calculus formation in these populations occurs coincident with periodontal disease (although the calculus itself appears to have little impact on attachment loss), the latter being correlated with dental plaque. In populations that do not practice regular hygiene and that do not have access to professional care, supragingival calculus occurs throughout the dentition and the extent of calculus formation can be extreme. In these populations, supragingival calculus is associated with the promotion of gingival recession. Subgingival calculus, in "low hygiene" populations, is extensive and is directly correlated with enhanced periodontal attachment loss. Despite extensive research, a complete understanding of the etiologic significance of subgingival calculus to periodontal disease remains elusive, due to inability to clearly differentiate effects of calculus versus "plaque on calculus". As a result, we are not entirely sure whether subgingival calculus is the cause or result of periodontal inflammation. Research suggests that subgingival calculus, at a minimum, may expand the radius of plaque induced periodontal injury. Removal of subgingival plaque and calculus remains the cornerstone of periodontal therapy. Calculus formation is the result of petrification of dental plaque biofilm, with mineral ions provided by bathing saliva or crevicular fluids. Supragingival calculus formation can be controlled by chemical mineralization inhibitors, applied in toothpastes or mouthrinses. These agents act to delay plaque calcification, keeping deposits in an amorphous non-hardened state to facilitate removal with regular hygiene. Clinical efficacy for these agents is typically assessed as the reduction in tartar area coverage on the teeth between dental cleaning. Research shows that topically applied mineralization inhibitors can also influence adhesion and hardness of calculus deposits on the tooth surface, facilitating removal. Future research in calculus may include the development of improved supragingival tartar control formulations, the development of treatments for the prevention of subgingival calculus formation, the development of improved methods for root detoxification and debridement and the development and application of sensitive diagnostic methods to assess subgingival debridement efficacy.

Predictors of tooth loss over 10 years in adult and elderly Chinese.

This study describes the incidence of tooth loss over a 10-year period in a population of rural Chinese, initially aged between 20 and 80 years. Among the 587 persons who participated in a baseline examination in 1984, 440 persons were available for a follow-up study in 1994. A total of 31 persons, mainly aged 50+ years at baseline, had become completely edentulous. Between 45% and 96% of the persons lost at least one tooth, and the average number of teeth lost ranged between 1.0 and 7.2. The distribution of the number of teeth lost was skew, indicating that a minor group of subjects had a substantially higher risk of tooth loss than the majority. Logistic regression analysis identified six significant predictors of tooth loss among those who remained dentate: age, a high number of teeth with dentinal caries lesions, a high number of teeth with caries lesions of any type, presence of teeth with attachment loss > or = 7 mm, presence of mobile teeth, and a low percentage of sites with subgingival calculus deposits. At the subject level, caries variables and periodontal disease variables seemed equally important predictors of the incidence of tooth loss over 10 years, but at the tooth level caries was a predominant cause of tooth loss in all age groups.

Location of probe tip in bleeding and non-bleeding pockets with minimal gingival inflammation.

In the present study the location of the probe tip was studied on human teeth scheduled for extraction for periodontal reasons. Prior to extraction all teeth were subjected to initial treatment consisting of plaque control and removal of supra- and subgingival deposits. Results showed that: 1) 43% of the pockets examined were still bleeding on probing after treatment 2) bleeding pockets were deeper than non-bleeding pockets 3) in non-bleeding pockets the probe tip was located more accurately at the attachment level than in bleeding pockets.

Effect of toothbrushing on subgingival plaque formation.

The purpose of the present study was to find out to what extent subgingival plaque formation may be prevented by toothbrushing. The experiment was carried out on a total of 28 molars in four monkeys. On day 0 all supra- and subgingival deposits were removed, and during the following year, the teeth on the left side were carefully brushed three times a week, employing the Bass' method. The right side was kept as unbrushed control. The histologic sections, which were cut in a bucco-lingual direction, showed that subgingival plaque almost invariably had developed on the unbrushed teeth. Although all of the brushed teeth were free of subgingival plaque, a mild to moderate cellular infiltration prevailed for some distance below the gingival margin. These inflammatory reactions were assumed to have been induced by the bristles of the toothbrush, which were shown to penetrate as far as 0.9 mm below the gingival margin, when employing the Bass method. It was concluded that subgingival plaque formation can be prevented in areas accessible to the toothbrush.

Influence of probing force on the reproducibility of bleeding tendency measurements.

Three groups of seven patients were selected on the basis of about 50% loss of alveolar bone support in some part of the mouth. All patients received initial treatment consisting of plaque control and removal of subgingival deposits. In the first group of patients 95 interproximal pockets were measured three times by one examiner using the pressure probe employing a constant probing force of 0.75 N. Bleeding or lack of bleeding from a pocket was sought for up to 30 seconds after probing. Results show that a time interval of 15 minutes between reexamination procedures is enough to prevent an increased bleeding index caused by repeated probing. In the second group of patients, 98 interproximal pockets were measured three times with a Merritt-B probe (Hu-Friedy), each time by a different examiner. In the third group of patients, 102 interproximal pockets were measured three times with a pressure probe, each time by a different examiner. The same three examiners were involved. In both groups presence or absence of bleeding from a pocket was recorded. Results show a proportion of interexaminer agreement among three examiners of 0.40 with the Merritt-B probe and 0.71 with the pressure probe. It is concluded that a constant probing force of 0.75 N does contribute to more reproducible bleeding tendency measurements.

The influence of probing force on the reproducibility of pocket depth measurements

Seven patients were selected on the basis of having about 50% loss of alveolar bone support in some part of the mouth. All patients received initial treatment consisting of plaque control and removal of subgingival deposits. In these patients, 102 interproximal pockets were measured by three different examiners, both with the pressure probe and a Merritt - B probe (Hu - Friedy). No specific instructions were given as to how the interproximal regions should be probed. Results indicate that a standardized probing force of 0.75 N does not lead to more reproducible pocket depth measurements.

Probing force and the relationship of the probe tip to the periodontal tissues

Abstract. Recently an increasing pocket depth was found to be related to an increasing probing force. The purpose of the present study was to investigate whether or not a plateau value in pocket depth measurements exists and to study, with different probing forces, the location of the tip of the probe in relation to the periodontal fibers and the alveolar bone. Two groups of patients were selected for this study; in one group a number of teeth had to be extracted for periodontal reasons (the extraction group) and in the other a single periodontal surgical procedure was required (the surgery group). All patients received preliminary treatment consisting of plaque control and removal of subgingival deposits. At the time of the investigation the gingival condition was assessed by means of a new index, the Periodontal Pocket Bleeding Index (P.P.B.I.) The criteria were: 0 ‐ no bleeding of the pocket after probing with a force of 0.75N, and 1 ‐ bleeding of the pocket within 30 sec after probing with a force of 0.75N. After local anesthesia in the extraction group, reference marks parallel to the long axis of the experimental teeth were cut with a cylindrical diamond burr. By means of the pressure probe, pocket depth measurements were performed with increasing forces of 0.50, 0.75, 1.00 and 1.25N. After extraction and staining of the remnants of the periodontal fibers, the distance from the most coronal intact connective tissue fibers to the most apical point of the reference marks was measured. In the surgery group using the same pressure probe, interproximal measurements with increasing forces of 0.50, 0.75, 1.00 and 1.25N were made from the apical border of the restorations to the bottom of the pocket. The same measurement, this time to the crest of the alveolar bone, was repeated after a flap had been raised.Results with the P.P.B.I. showed that oral hygiene procedures resulted in a mean index of 0.36 in the surgery group and 0.43 in the extraction group. The results of the present study indicated that 1) using a probe of 0.63 mm diameter, the optimal force level for clinical pocket depth measurements is 0.75N, 2) a force of 0.75N is clinically well tolerated and meets with few objections from patients, 3) when a probing force of 0.75N is used the tip of the probe in both shallow and deep periodontal pockets is located at the most coronal intact connective tissue fibers, 4) a plateau value in pocket depth measurements is found when a probing force of 1.25N is employed, and 5) the mean width of the connective tissue attachment is approximately 1.9 mm.

Ultrastructure of the subgingival microflora in juvenile periodontitis

The ultrastructure of the subgingival deposits on the root surfaces of teeth affected by juvenile periodontitis was studied on 12 teeth from nine individuals, 15--30 years of age. The deposits consisted of either microbial masses associated with a pellicle, or of a cuticular material almost free of bacteria. Gram-negative rods and filaments were the predominant microorganisms. "Corncob" configurations consisting of filamentous bacteria surrounded by Gram-positive cocci, and "bristle brush" formations comprising corncobs surrounded by long rods were observed in the superficial layer of the plaque. Spirochetes and flagellated rods constituted a major segment of the microflora. The present data indicated that the deep pockets in juvenile periodontitis harbor a sparse but relatively characteristic microbial population.

Introduction of a new periodontal probe: the pressure probe

Abstract. A new periodontal probe has been developed: the pressure probe. The probe consists of a cylinder and piston assembly connected to a variable air pressure system. The working end is a metal tube in which a plunger can move freely. By means of air pressure the plunger is constantly fully extruded. During probing the plunger will intrude from the position of maximum extrusion only as the probing force exceeds the predetemined force acting on the plunger. The difference by which the plunger is intruded can be read on a millimeter scale within the handle of the probe. The purpose of the present investigation was to determine whether probing force is constant during probing, to study the reliability of reading pocket depth measurements in vitro, and to investigate the relationship between pocket depth and applied force in man. In order to evaluate whether the probing force is constant during probing, measurements were performed on a force transducer. Results show that the device makes probing possible with a constant and adjustable pressure. The influence of the reading of the calibration on pocket depth assessment in vitro was studied in an in vitro model. Results show that pocket depths of 1 mm to 8 mm ± 0.25 mm were read correctly in about 90 % of instances. Generally about 45 % of the half millimeter values were recorded as the lower whole millimeter. To investigate the relationship between pocket depth and applied force, 173 pocket depth measurements were performed in eight patients. Patients selected for this study had, in some part of the upper anterior segment, loss of alveolar bone support up to two‐thirds of the root length, visible on periapical radiographs. All patients received preliminary treatment consisting of plaque control and removal of subgingival deposits. The mean Sulcus Bleeding index score was 0.2. Pocket depth measurements were carried out with forces of 0.15, 0.25, 0.50 and 0.75 N. Both approximal and vestibular pocket depths were recorded. In this study 0.75 N was chosen as the maximal force since in a pilot study a force of 1.0 N appeared too painful for patients. Results show an increasing pocket depth with increasing probing force. The mean pocket depths increased from 2.08 mm at 0.15 N to 3.71 mm at 0.75 N. Testing showed it to be statistically significant. At 0.75 N, 72 out of the 173 pockets examined were equal to or deeper than 4 mm. The percentages were calculated of differences equal to or more than 2 mm between pocket depth measurements carried out with 0.75 N and lower forces. It was found that 63.3 % of pocket depths measured with 0.15 N were, when measured with 0.75 N, 2 mm or more deeper. This was 43.1 % when 0.25 N and 0.75 N were compared and 9.7 % when 0.50 N and 0.75 N were compared. The maximal differences varied from 5 mm to 7 mm.

Periodontal disease in a Beagle dog colony

The histological and macroscopic features of periodontal disease were examined in 40 Beagle dogs, aged between 1 and 8 years. Subclinical gingivitis was associated with the presence of a few polymorphonuclear leucocytes within the sulcular and junctional epithelium and a mild inflammatory cell infiltration of the underlying connective tissue. In established gingivitis the junctional epithelium proliferated into the underlying connective tissue which was densely infiltrated by inflammatory cells mainly of the plasma cell type and large numbers of polymorphonuclear leucocytes accumulated between the sulcular epithelium and the subgingival deposits of bacterial plaque. The progressive destruction of the connective tissue attachment to the tooth was associated with migration of the junctional epithelium beyond the cement-enamel junction and loss of alveolar bone. The results suggest that the Beagle dog may be a useful research model for the further study of periodontal disease and its prevention.

Conservative treatment of periodontal disease

In order to effect a cure of periodontal disease, all known causes that produce this disease and the effects of those causes must be removed and tissue re­ sistance must be raised.1 Conservative periodontal treatment should utilize all of the reparative processes of the body in eliminating the disease with a minimum of tissue loss. Once maximum oral health has been achieved, it should be main­ tained at that level. Pocket reduction and elimination are one of the aims of conservative treatment. If surgery is attempted first, one of the effects of the disease is eliminated—not the causes.-Afterward conservative meth­ ods, such as instrumentation, home-care and dietary correction, must be instituted to effect a fcure. Therefore, conservative treatment should be used first, as in many instances it obviates the necessity for surgical treatment. In attempting periodontal treatment, the following steps should be taken: the making of a diagnosis and a prognosis; the removal of such irritants as supragingival deposits, subgingival deposits, mechanical, chemical and atmospheric irritants, destructive habits and food im­ paction; the institution of proper home care methods; the correction and fortifi­ cation of nutrition; the equilibration of occlusion; temporary splinting, when in­ dicated; surgery when necessary and the polishing of all exposed tooth surfaces. The removal of common irritants and the best methods of home care to effect the desired goal should be discussed in more detail.