Periodontal regeneration of a class II furcation defect utilizing a bioabsorbable barrier in a human. A case study with histology

This case report describes human histologic data of periodontal regeneration following guided tissue regeneration therapy (GTR) with a bioabsorbable barrier composed of polylactic acid. The tooth that was examined was part of a previously published study of the clinical effects of GTR therapy without the use of bone or bone substitutes on Class II furcation defects. Twenty-five months following the surgical procedure, the tooth was extracted for non-periodontal reasons. During this extraction, the bone within the furcation that was treated in the study was luxated with the tooth. At the completion of the study (month 12), the furcation's vertical probing depth had decreased by 2 mm with a 2 mm gain in clinical attachment. The horizontal furcation measurement decreased by 3 mm. Following extraction, the tooth was prepared for light microscopy and sectioned in the mesial-distal plane. Reference notches were not placed in the tooth at the time of surgery as there were no plans to perform histologic analysis in the study. However, using the buccal root prominences and what we interpreted to be root planing marks on the cementum, we were able to demonstrate that complete periodontal regeneration occurred on the root surface that was exposed to the pocket environment prior to surgery. New alveolar bone, cementum, and periodontal ligament were consistently observed throughout the furcation in the areas that demonstrated clinical attachment gain and a decrease in horizontal probing depth. This case report adds to the accumulating evidence of histologic periodontal regeneration following guided tissue regeneration with bioabsorbable polylactic acid barriers.

The use of distraction osteogenesis to induce new suprabony periodontal attachment in the beagle dog

Using a technique called distraction osteogenesis (DO), orthopedic surgeons are capable of reconstructing 4 to 5 cm of bone and soft tissue without bone grafts or pedicle flap procedures. DO has been used recently to generate maxillofacial bone as an alternative to maxillary and mandibular osteotomies. Using DO methodology, this study attempted to regenerate supraalveolar buccal periodontium on the mandibular second, third, and fourth premolars of beagle dogs. A small but statistically significantly greater amount of new cementum was generated in experimental teeth, with no difference found between experimental and control groups with respect to regenerating alveolar bone. Further studies using modifications of this technique are warranted to explore the potential of DO as an alternative to conventional regenerative approaches.

Use of Emdogain in the treatment of deep intrabony defects: 12-month clinical results. Histologic and radiographic evaluation

The objective of this study was to evaluate the application of an enamel matrix derivative (Emdogain) in deep periodontal pocket therapy. Twenty-one patients presenting intrabony and interproximal defects that could be treated with guided tissue regeneration were selected. The intrabony defects were divided into deep (< 9 mm) and very deep (> or = 9 mm) defects. Bleeding on probing, Plaque Index, probing pocket depth, mobility index, gingival recession, probing attachment level, and surgical bone level were measured at baseline. At 12 months, cases were reexamined and indices recorded again. The mean probing depth decreased from 8.1 +/- 2.1 mm to 3.2 +/- 1.5 mm; attachment level decreased from 10.4 +/- 2.4 mm to 7.0 +/- 1.8 mm; recession increased from 2.3 +/- 1.4 mm to 3.8 +/- 1.8 mm; and surgical bone level decreased from 9.6 +/- 1.9 mm to 7.1 +/- 1.5 mm. No significant difference wa noted between bone defects with one or 2 walls, between local and generalized periodontitis, or between smokers and nonsmokers. Significant statistical difference was found, however, between deep intrabony defects and very deep defects when attachment gain was considered. No adverse reaction to the substance was noted. The good clinical results obtained were not confirmed by radiologic results; standardized and computerized radiographs at 12 months did not reveal significant improvement. The histologic examination carried out on 2 samples did not show evidence of new attachment. Further studies are necessary to clarify the action mechanism and to evaluate the long-term results of this method.

Human histologic evaluation of bioactive ceramic in the treatment of periodontal osseous defects

This study examined the healing of intrabony defects around 5 teeth treated with bioactive glass ceramic (PerioGlas). Healing was evaluated by clinical measurements, radiographic observation, and histologic analysis. The protocol included a presurgical phase of scaling and root planing therapy, with measurements obtained immediately prior to the surgical procedures and after 6 months of healing. Following therapy there was a mean of 2.7 mm of probing depth reduction, 2.2 mm of clinical attachment gain, and 0.5 mm of recession. The histologic analysis revealed healing by a long junctional epithelium with minimal new connective tissue attachment to the teeth, except in one case where the intrabony region demonstrated new cementum formation and new connective tissue attachment. Graft particles were found to be biocompatible, as evidenced by being embedded in a stroma of dense connective tissue with minimal inflammatory infiltrate. There was minimal new bone formation limited to the most apical borders of the defects. No signs of periodontal regeneration as defined by new cementum, periodontal ligament, and bone formation on a previously diseased root surface were observed. Although the clinical results are encouraging and radiographs evidenced radiopacities within the defects, histologic analysis revealed that as a periodontal grafting material, bioactive glass ceramic has only limited regenerative properties.

Human histologic evaluation of a bone graft combined with GTR in the treatment of osseous dehiscence defects: a case report

There are many possible goals and outcomes of periodontal surgical therapy, but the ultimate goal is regeneration. Since the definition of periodontal regeneration is histologic, it is difficult to document. The purpose of this study was to evaluate a technique that combined a bone graft and guided tissue regeneration (GTR) to see if regeneration occurred. Four teeth with dehiscence-type osseous defects that were scheduled for extraction were treated with bone grafts and GTR. During the surgical procedure, a notch was placed into the root at the apical extent of the calculus. The teeth were extracted with conservative block sections 7 months after the treatment. They were processed, sectioned, stained, and evaluated histologically. The results revealed that regeneration did not occur in any of the teeth treated. In 2 of the teeth new connective tissue attachment was formed. In these 2 teeth cementum could be seen in the notch with connective tissue fibers inserting into the cementum. In one of the teeth the junctional epithelium extended apical to the notch, while in 3 cases the epithelium stopped at or coronal to the notch. In this case report, no regeneration could be documented, but new attachment could be seen in 2 of the 4 teeth treated.

Effects of hypothalamic-pituitary-adrenal axis reactivity on periodontal tissue destruction in rats

The aim of this study was to test the hypothesis of an association between hypothalamic-pituitary-adrenal (HPA) axis reactivity and progression of periodontal disease. Histocompatible Lewis and Fischer 344 rats respond to stressful stimuli with low and high HPA axis reactivity, respectively. Experimental periodontitis was induced by tying a silk ligature around the neck of maxillary 2nd right molar teeth in 10 Lewis and 10 Fischer 344 rats with contralateral non-manipulated teeth as controls. Twenty non-manipulated animals were included. Also, experimental periodontitis was induced in 10 adrenalectomized Wistar rats and in 10 sham-operated rats. Furthermore, corticosterone pellets were subcutaneously implanted in 9 Lewis rats, while placebo pellets were implanted in 8 animals. Disease progression was evaluated histometrically and radiographically. The low-responding Lewis rats developed significantly less periodontal breakdown than did the high-responding Fischer 344 rats. Administration of corticosterone increased the disease development. while adrenalectomy reduced the disease severity. Our findings demonstrate the importance of genetic factors in the development of periodontal disease, and suggest that HPA axis hyper-activation is one mechanism by which periodontal disease susceptibility may be increased.

Comparisons of clinical and radiographic measurements of inter-proximal vertical defects before and 1 year after surgical treatments

BACKGROUND

Radiographic measurements are often used as a substitute for direct clinical measurements requiring re-entry surgery for follow-up outcome studies.

AIMS

(1) To assess the reliability of clinical and radiographic measurements of periodontal defects as compared to direct bone measurements during surgical procedures, and (2) to assess the associations between selected clinical and radiographic measurements of periodontal inter-proximal defects.

METHODS

57 inter-proximal periodontal defects were measured at baseline and at 12 months after surgical treatment. Direct measurements during surgery of the distance between the CEJ to the bottom of defects (ABL) were compared with probing to bone (PB), probing attachment level (PAL), and radiographic measurements.

RESULTS

Probing to bone is an accurate measure to assess inter-proximal bone level as compared to ABL (mean difference: 0.1 mm) and that intra-oral standardized radiographs underestimate bone level and defect depth by approximately 1.4 mm. The interpretation of periodontal changes between baseline and 12 months after treatment by probing to bone, or PAL measurements, or from radiographic images yield almost identical results (mean difference< or =0.2 mm). For the assessments of changes over time using PB change as the standard, intra-class correlation (ICC) coefficients varied between 0.52 to 0.90. The best ICC coefficient was found for relative attachment level change assessed by the Florida probe (0.90), and with an ICC value of 0.61 for changes assessed from intra-oral radiographs. Two-way analysis of variance failed to demonstrate differences between sets of comparisons.

CONCLUSIONS

Both radiographic interpretations of changes over time, and measurements of attachment level changes are reliable in assessing the treatment outcome of inter-proximal intra-bony defects when compared to probing to bone changes as the standard method.

Changes in the periodontal status of patients undergoing bone marrow transplantation

BACKGROUND

Patients receiving an HLA-matched bone marrow transplant (BMT) from a relative or unrelated donor undergo a permanent alteration of their immune system, followed by a prolonged period of immunodeficiency. This study aimed to examine alterations in the periodontal status of patients over 6 months post-bone marrow transplantation.

METHODS

Thirty-seven patients scheduled for bone marrow transplantation participated in this study. One calibrated examiner carried out periodontal examinations (clinical and radiographic) immediately prior to and at 3 and 6 months after transplantation. All patients followed an intense oral care program. Subgingival plaque samples were analyzed by enzyme-linked immunosorbent assay (ELISA) for the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Prevotella intermedia. Data were subjected to statistical analyses to determine the relationships between the frequency distribution of the radiographic and clinical variables over time.

RESULTS

Gains in clinical attachment level (CAL) of > or =2 mm at 4 or more sites from baseline to 6 months post-BMT were noted in 9/16 patients (56%), while 6/16 (38%) patients experienced a loss of CAL > or =2 mm at 4 or more sites in the same period. At a site level, 4.8% of sites exhibited a gain in CAL > or =2 mm between baseline and 3 months post-BMT while 2.3% of sites showed a loss of CAL > or =2 mm in the same period. From baseline to 6 months, a gain in CAL of > or =2 mm was recorded at 3.1% of sites, and 2.4% of sites experienced a loss of > or =2 mm. A significant improvement in the gingival index occurred between all sequential time periods when assessed at a site level. At a patient level, 11/18 (61%) patients showed a significant change in gingival index between baseline and 3 months and 10/16 (63%) between baseline and 6 months. There was no significant relationship between clinical changes and the prevalence of the periodontal pathogens at the various time periods.

CONCLUSIONS

An improvement in periodontal health was recorded between baseline and 6 months post-transplantation. Most of the improvement in periodontal status was noted in the first 3 months after BMT, with a slight decline in periodontal health between 3 and 6 months post-transplant. No significant alteration was noted in the prevalence of periodontal pathogens during the study period.

The effect of scaling and root planing on the clinical and microbiological parameters of periodontal diseases: 12-month results

BACKGROUND/AIMS

Previously, we reported that SRP resulted in a decrease in mean pocket depth and attachment level and reduced prevalence and levels of Bacteroidesforsythus, Porphyromonas gingivalis, and Treponema denticola at 3 and 6 months post-SRP in 57 subjects with adult periodontitis. 32 of the 57 subjects were monitored at 9 and 12 months. Thus, the purpose of the present investigation was to evaluate the microbial and clinical effects of SRP in 32 (mean age 48+/-11) subjects over a 12-month period.

METHOD

Clinical assessments of plaque, gingival redness, suppuration, bleeding on probing, pocket depth and attachment level were made prior to SRP and at 3, 6, 9, and 12 months post-therapy. Subgingival plaque samples were taken at each visit and analyzed using the checkerboard DNA-DNA hybridization technique for the presence and levels of 40 subgingival species. Each subject also received maintenance scaling at each of the subsequent monitoring visits. Differences in clinical parameters and prevalence and levels of bacterial species were analyzed pre- and post-therapy using the Wilcoxon signed ranks test. The Quade test for related samples was used for analysis of multiple visits.

RESULTS

Mean pocket depth (mm+/-SEM) decreased from 3.2+/-0.3 at baseline to 2.9+/-0.3 at 12 months (p<0.01). Mean attachment level showed significant reduction at 6 months, but did not diminish further. Bleeding on probing and plaque were significantly reduced at 12 months (p<0.001, p<0.05, respectively). P. gingivalis, B. forsythus and T. denticola decreased in prevalence and levels up to the 6-month visit and remained at these lower levels at 9 and 12 months. Significant increases in levels and prevalence were noted at 12 months for Actinomyces naeslundii genospecies 2, Actinomyces odontolyticus, Fusobacterium nucleatum ss polymorphum, Streptococcus mitis, Capnocytophaga sp, and Veillonella parvula.

CONCLUSIONS

The data suggest that the maintenance phase of therapy may be essential in consolidating clinical and microbiological improvements achieved as a result of initial therapy.

Long-term results of a minimally invasive surgical approach for bone grafting

A retrospective analysis of the results obtained from regenerative surgery performed utilizing a minimally invasive surgical approach was performed. Bone grafting procedures were performed at 194 sites in 87 patients using small incisions and minimal flap reflection. There were 44 females with a mean age of 52.7 years and 43 males with a mean age of 54.9 years. The mean healing time at which data were collected was 21.7 months. Postsurgical data were collected at the time of routinely scheduled supportive periodontal therapy (SPT) appointments by 2 evaluators. Mean changes in probing depth and attachment levels were evaluated utilizing a Wilcoxon sign rank test. Mean improvement in probing depth was 4.58 mm (P <0.0001) and attachment level was 4.87 mm (P <0.0001). These improvements were seen for all levels of initial prognosis (good to poor) and appeared to be stable over time. The postsurgical gingival margin was at or within 1 mm of the cemento-enamel junction (CEJ) for 58% of the sites treated. This was interpreted to indicate good retention of soft tissue height postsurgically. It was concluded that the minimally invasive approach for bone grafting yielded results that were equivalent to more traditional surgical approaches utilizing longer incisions and greater reflection.

Influence of different curette insertion depths on the outcome of non-surgical periodontal treatment

This study was undertaken to compare the effects of scaling and root planing (Sc/RP) performed from approximately 1 mm coronal to (test Sc/RP) or at the bottom of (control Sc/RP) the probeable pocket to the gingival margin. 2 male and 5 female patients with moderate to severe periodontitis participated in the study. Initial examination was performed with respect to probing pocket depth (PPD) and probing attachment level (PAL) using a pressure-controlled periodontal probe and stents. The patients received repeated instruction in oral hygiene, and their plaque control reached an excellent level. Baseline examination including PPD and PAL measurements was then performed. Following the baseline examination, single-rooted teeth in 1 quadrant of each dentition were randomly selected and subjected to the test Sc/RP (test teeth) or control Sc/RP (control teeth). The PPD and PAL were measured 1 and 3 months following Sc/RP. It was demonstrated that: (i) the PPD reduction following Sc/RP was larger at the sites with initially deep pockets than at the sites with shallow pockets; (ii) the mean PPD reduction at the sites with an initial PPD > or =3.5 mm was significantly larger in the control teeth than in the test teeth; (iii) there was a significant PAL gain in the initially deep pockets but not in the initially shallow pockets; (iv) the PAL gain in the initially shallow pockets was significantly larger in the control teeth than in the test teeth. In the treatment of periodontitis, trauma caused by Sc/RP to the most coronal part of the connective tissue attachment seems to be of minor importance compared to the effective removal of subgingival deposits.

Periodontal and dental lesions in raccoons from a farming and a recreational area in Illinois

Dental health was evaluated in two populations of raccoons (Procyon lotor) in western Illinois (USA); one was from a rural agricultural area with low human density and the other from a nearby state park heavily used by humans and raccoons. From 1989 through 1993, 300 raccoons were live-trapped in the agricultural area and 246 raccoons were live-trapped in the park. Oral health was assessed using gingival and calculi indices and by measuring loss of attachment and tooth wear. Raccoons from the park were significantly older and smaller, but not thinner, than raccoons from the farmed area. Gingival and periodontal indices, tooth wear, tooth loss, and caries increased significantly from juveniles to yearlings to adults, at both sites. Males had higher levels of gingivitis and loss of periodontal attachment than females, but were similar on other dental measures. There were no seasonal differences between raccoons in dental indices. Animals with high scores for one oral measure tended to have high values for all indices. Dental health was generally good for juveniles and yearlings from both sites. Among adults, periodontal indices and the prevalence of caries were significantly higher in the park, but prevalence of broken or missing teeth was similar for both populations. There was no association between body condition, and a higher dental score or more missing or broken teeth.

Coronally advanced flap procedure for root coverage. Is flap thickness a relevant predictor to achieve root coverage? A 19-case series

This clinical study was designed to determine whether the thickness of the flap can influence root coverage when gingival recessions associated with traumatic toothbrushing are treated using a coronally advanced flap (CAF). Nineteen patients, aged from 25 to 57 years, with high levels of oral hygiene (full-mouth plaque scores <20%) were selected for the study. Each patient contributed with one Miller Class I or II maxillary or mandibular recession. A total of 19 recessions > or =2 mm were treated. After local anesthesia and before flap elevation, the exposed root surface was planed with a sharp curet. A trapezoidal full- and partial-thickness flap was then elevated, displaced coronally, and sutured to cover the treated root surface. Before suturing, flap thickness was measured in the alveolar mucosa with a gauge. After surgery, all patients were recalled for control and professional prophylaxis once a week during the first month and monthly up to the third month. The mean initial recession depth was 3.0+/-0.9 mm. Mean flap thickness (FT) was 0.7+/-0.2 mm. Three months later, mean recession depth was 0.6+/-0.6 (P <0.0001) and mean recession reduction was 2.4+/-0.7 mm. Mean root coverage was 82+/-17%. Flap thickness >0.8 mm was associated with 100% of root coverage. The results of this study indicate that there is a direct relation between flap thickness and recession reduction (P <0.0001).

Discrimination of refractory periodontitis subjects using clinical and laboratory parameters alone and in combination

The purpose of the present investigation was to use baseline clinical and laboratory parameters to distinguish subjects refractory to conventional periodontal therapy. Baseline clinical, microbial and host parameters were compared in 61 successfully-treated and 27 refractory subjects. Refractory subjects showed mean full-mouth attachment level (AL) loss and/or >3 sites with new AL loss >2.5 mm within 1 year after both scaling and root planing and surgery with systemic tetracycline. Successfully-treated subjects showed mean AL gain and no sites with new AL loss >2.5 mm after either regimen. Gingival redness, bleeding on probing, suppuration, supragingival plaque accumulation, pocket depth and AL were measured at 6 sites per tooth in each subject. The levels of 40 subgingival taxa were determined in subgingival plaque samples from up to 28 sites in each subject using checkerboard DNA-DNA hybridization. Serum antibody (Ab) to 85 subgingival species was determined using checkerboard immunoblotting. Levels of serum IgG2 and Gm23 allotype were measured using radial immunodiffusion; FcgammaRIIa and FcgammaRIIIb receptor haplotypes were determined using PCR and allele specific oligonucleotide probes. Odds ratios of a subject being refractory were determined by comparing measured parameters in the 2 subject groups using univariate and multivariate techniques. 17 of 151 clinical, microbial and immunological variables were significant using chi2 analysis after adjusting for multiple comparisons. For example, the odds ratios of a subject being refractory were 12.2, 5.4 and 6.9 if the subject had Ab >50 microg/ml to >9 species; S. constellatus counts >2.4% of the total DNA probe count or >2.1% of sites with AL >6 mm. The 17 significant predictor variables were used in logistic regression and discriminant analyses. Similar variables were selected using both analyses including the number of serum Ab to subgingival species >50 microg/ml, % S. constellatus in plaque samples and % sites with attachment loss >6 mm. In the logistic regression analysis model, the odds ratios associated with >9 species exhibiting >Ab 50 microg/ml, >2.1% of sites with AL >6 mm and >2.4% S. constellatus in plaque were 8.7, 6.8 and 2.4, respectively, after adjusting for other variables in the model. Discriminant analysis using these variables provided sensitivity, specificity, positive and negative predictive values of 0.66, 0.92, 0.80 and 0.85 respectively. Refractory periodontitis subjects could be distinguished using a subset of clinical, microbiological and immunological parameters.

Use of bovine-derived anorganic bone associated with guided tissue regeneration in intrabony defects. Six-month evaluation at re-entry

BACKGROUND

Different filling materials have been associated with guided tissue regeneration (GTR) in order to improve its regenerative potential and predictability. Anorganic bovine bone (ABB) has demonstrated biocompatibility and osteoconductive properties; however, there are limited data regarding its performance in the treatment of intrabony defects. This investigation aimed to evaluate the clinical outcome of the association of anorganic bovine bone with cellulose membranes in intrabony defects after 6 months.

METHODS

Twenty-six paired intrabony defects were selected from 11 non-smoking patients with no relevant medical history. The defects were similar regarding the number of bony walls and defect depth, and presented pocket depths > or = 6 mm. Four weeks after completion of basic therapy, probing depth (PD), clinical attachment level (CAL), and gingival margin position (GP) were recorded (baseline values). The defects were then surgically accessed and debrided, and the intrabony component measured to the nearest millimeter with periodontal probes and customized acrylic stents (distance from the stent to the base of the defect and from the stent to the alveolar crest). Each intrabony defect was randomly assigned to receive the membrane alone (control, C) or the membrane with anorganic bovine bone (test, T). The patients were re-evaluated after 6 months, and re-entry procedures were performed.

RESULTS

Significant (P <0.01) improvement in all variables was observed: mean pocket reduction of 4.61+/-1.60 mm (C) and 4.46+/-1.50 mm (T) and clinical attachment gain of 2.85+/-1.46 mm (C) and 3.15+/-1.40 mm (T); the difference between groups was not significant (P >0.05). Nevertheless, gingival recession in the control group (1.84+/-0.89 mm) was significantly (P <0.05) more pronounced than that observed in the test group (1.30+/-0.48 mm). Bone measurements indicated a significant resolution of the defects (P <0.01). A mean defect resolution of 2.76+/-0.72 mm (C) and 2.69+/-1.03 mm (T) and crestal resorption of 1.07+/-0.64 mm (C) and 1.30+/-0.85 mm (T) were detected (P >0.05). Stepwise multiple regression analysis indicated that for both groups, the baseline depth of the defects and the alveolar crest resorption accounted for 82% of the variability of bone fill observed in the control group (F = 23.65, P <0.001) and 89% in the test group (F = 41.32, P <0.001).

CONCLUSIONS

ABB may be used in conjunction with GTR in the treatment of intrabony defects. Its use, however, did not result in a better outcome than the use of membranes alone. Studies employing more patients would be of interest in order to determine the advantages and indications of the tested approaches on a more predictable basis.

Coronally advanced flap procedure for root coverage. Treatment of root surface: root planning versus polishing

This clinical study was designed to determine if mechanical instrumentation (root planing) of the exposed root is useful in treating gingival recession caused by traumatic toothbrushing following a coronally advanced flap (CAF). Ten patients with high levels of oral hygiene (full-mouth plaque score <20%), from 25 to 57 years of age, were selected for the study. Each patient showed 2 bilateral Class I or II maxillary recessions. A total of 20 recessions were treated. The difference in the recessions was < or =1 mm. In each patient, one recession was randomly assigned to the test group and the contralateral one to the control group. In the test group, the exposed root surface was polished at slow speed with a rubber cup and prophylaxis paste for 60 seconds. In the control group, the exposed root surface was planed with a sharp curet. In both test and control groups, a trapezoidal full- and partial-thickness flap was elevated, coronally displaced, and sutured to cover the treated root surface. Before treatment, the mean recession depth in the test group (polishing) was 3.1+/-1.1 mm; and in the control group (root planing), 2.9+/-1.0 mm. Three months after the described procedures, the test group (polishing) showed a mean recession reduction of 2.6+/-0.6 mm; mean percent root coverage was 89+/-14%. In the control group (root planing), the mean recession reduction was 2.3+/-0.7 mm and mean percent root coverage was 83+/-16%. The difference of recession reduction between the test and control group was not statistically significant (P = 0.1405), even though the test group showed slightly better clinical results in terms of root coverage. This prospective clinical, controlled, randomized study shows that mechanical instrumentation (root planing) of the exposed root surfaces is not necessary when shallow recessions caused by traumatic toothbrushing are treated using a coronally advanced flap (CAF) in patients with high levels of oral hygiene.

Relationships between longitudinal changes in radiographic alveolar bone height and probing depth measurements: data from postmenopausal women

BACKGROUND

The relationship between loss of radiographic alveolar bone height and probing attachment loss has been studied by a number of investigators, with mixed results. Recent studies have found weak correlations and have suggested that the relationship between bone loss and attachment loss is complex, perhaps because changes in bone height and attachment level are separated in time.

METHODS

The 85 patients in this report were part of a prospective estrogen replacement interventional study. All patients were in good oral health at entry and received annual oral prophylaxis as part of the study. Standard probing measurements were made with a pressure-sensitive probe at 6 sites on each tooth. Vertical bite-wing radiographs were taken of each patient, radiographs were digitized, and 6 linear measurements (corresponding to probing site measurements) were made from the cemento-enamel junction to the alveolar crest. These procedures were performed at baseline and at annual intervals; this study reports results after 2 years. Data were analyzed both by individual site and by averaging identical sites from all measured teeth for each patient.

RESULTS

Very weak direct relationships between change in alveolar bone height and change in attachment level were found in both the site data (r2=0.0022; P = 0.189) and the patient average data (r2=0.031; P= 0.104).

CONCLUSIONS

The changes in these patients were probably due to systemic changes in bone health rather than to periodontal disease. However, the weak correlations between changes in attachment level and bone height are similar to recent studies of periodontal disease. Our results support suggestions in the literature that the link between changes in attachment and alveolar bone height is complex, perhaps because changes in the 2 tissue types are separated by a considerable time delay.

Measurement of clinical attachment levels using a constant-force periodontal probe modified to detect the cemento-enamel junction

The handpiece of a Florida sleeve probe was modified to create a flange with the capability to detect the cemento-enamel junction (CEJ). This new instrument (the Pressure-controlled, Automated, Standardised Handpiece or Florida PASHA probe) was used to determine whether (a) the CEJ could be reproducibly detected in dried, human skulls and (b) clinical attachment levels could be reliably measured in human subjects. When using the Florida PASHA probe to detect the CEJ at 157 different sites in four dried, human skulls, there were no statistically significant (p > or = 0.15) differences in mean CEJ detection measurements for any of the three participating examiners; either when the CEJ was visualised or obscured. The mean differences between first and second replicates ranged from 0.00 to 0.08 mm. Intraclass correlation coefficients (ICCs) of repeated measures in both conditions ranged from 0.70 to 0.83 for tactile CEJ detection (CEJ obscured), and from 0.95 to 0.96 for visual detection (CEJ visible). In human studies, the Florida PASHA probe was used by two examiners to determine clinical attachment levels (CAL) at 660 sites in 5 human subjects undergoing supportive periodontal therapy. Intra-examiner agreement of replicate measurements recorded by the probe, as measured by calculating ICCs, ranged from 0.79 to 0.85 for the 2 examiners, respectively. A statistically significant inter-examiner difference in mean CAL measurements when using the Florida PASHA probe was found (p<0.001). Notwithstanding this difference, inter-examiner agreement was good, with an ICC of 0.83. These data suggest that the Florida PASHA probe can reproducibly detect the CEJ and is proposed as a tool for measuring CAL in humans.

Antibody reactive with Porphyromonas gingivalis serotypes K1-6 in adult and generalized early-onset periodontitis

BACKGROUND

Six serotypes of Porphyromonas gingivalis have recently been described. We sought to test the hypothesis that serotype specific carbohydrates from these strains are important antigens that elicit potent immune responses.

METHODS

Serum concentrations of IgG reactive with P. gingivalis serotypes K1-K6 were determined for 28 adult (AP) and 28 generalized early-onset (G-EOP) periodontitis patients previously determined to be seropositive for a broken cell preparation of P. gingivalis. To confirm relationships suggested for K1, K2, and K6 in the analysis of initial data, the study population was increased to 133.

RESULTS

Frequency of seropositivity for the 6 serotypes ranged from 26 to 54% of subjects. IgG concentrations ranged from 0 to 453 microg/ml with many subjects seropositive to more than one serotype. Concentrations for the subset of patients who was seropositive were high (mean responses ranged from 20 to 105 microg/ml for the 6 serotypes). Significant correlations between seropositivity to serotypes K1 and K5 as well as between K5 and K6 were found.

CONCLUSIONS

We examined the relationship of diagnosis, race, gender, smoking, probing depth, attachment loss, and antibody reaction with the P. gingivalis serotypes by analysis of variance. Initial findings suggested potential relationships between diagnosis, smoking, race, gender, and antibody reactive with serotypes K1, K2, and K6. A significant relationship did exist between smoking and decreased antibody reactive with P. gingivalis serotype K2. No other relationships were substantiated. We also examined the IgG subclass distribution and found that responses were almost exclusively IgG2. These data support the concept that antibody responses to all 6 serotypes are common in both AP and G-EOP and that these K serotype carbohydrates elicit potent IgG2 responses.

Digital radiography of interproximal bone loss; validity of different filters

The aim of the present study was to compare linear measurements of interproximal bone loss on digitized radiographic images after application of different filters to the gold standard of intrasurgical measurements. Immediately before surgery, 50 radiographs of 50 periodontally-diseased teeth exhibiting interproximal bone loss, were obtained by a standardized technique in 33 patients. Intrasurgically, the distances from the cementoenamel junction (CEJ) to the alveolar crest (AC) and from the CEJ to the deepest extension of the bony defect (BD) were assessed. All radiographs were digitized with a flatbed scanner (resolution: 600x1200 dpi). Using the FRIACOM-soft-ware, the linear distances CEJ to AC and CEJ to BD were measured at 50 interproximal lesions from the digitized but unchanged radiographic images and also after use of 7 different basic image-processing modes (enhancement of contrast [dynamics], inversion, high-pass, enhancement of gray-level differences, mean value, histogram correction, spreading of grey values) with 11-fold magnification. Neither the measurement of the distance CEJ to AC on the unchanged images nor assessments with any of the filters revealed significant differences from the gold standard. Multivariate analysis of variance showed the respective filter (p=0.009), intrasurgical and radiographic assessments (p<0.0001), to statistically significantly, influence the difference between intrasurgical and radiographic measurements of the distance CEJ to BD. The underestimation of the intra-surgically assessed distance CEJ to BD by radiographic measurements ranged from 0.3+/-2.0 to 0.8+/-1.9 mm. The filter "mean value" underestimated interproximal bone loss statistically significantly more than the digitized but unchanged radiograph (p=0.05). In this study, basic digital manipulations (filters) of radiographic images failed to result in statistically significantly more valid measurements of interproximal bone loss when compared to the unchanged but digitized images. All radiographic assessments on the digitized images except for use of one filter (mean value) came close to the intrasurgical gold standard.

The use of 2 bioabsorbable barrier membranes in the treatment of interproximal intrabony periodontal defects

BACKGROUND

The use of barrier membranes in the treatment of periodontal defects is well documented. There has been an increase in the use of bioabsorbable materials which do not require a second surgical procedure for removal. However, there are little data evaluating the efficacy of bioabsorbable membranes in the treatment of intrabony defects. The purpose of this investigation was to evaluate the regenerative potential of 2 bioabsorbable barrier membranes without the use of grafting materials in the treatment of interdental intrabony defects.

METHODS

Twenty-three 2- or 3-walled intrabony defects were treated in 19 patients with a mean age of 50.4 years. All had completed nonsurgical treatment and a period of supportive periodontal therapy. The sites were randomly chosen to receive a barrier membrane composed of type I bovine collagen (11) or a copolymer of polylactic acid (PGA/PLA;12). A pressure sensitive disc probe was used to evaluate the following criteria at baseline and re-entry: 1) occlusal surface to the apical depth of probe penetration (OS-DP); 2) occlusal surface to the gingival margin (OS-GM); 3) occlusal surface to the alveolar crest (OS-AC); and 4) occlusal surface to the base of the osseous defect (OS-BD). Full thickness mucoperiosteal flaps were reflected to expose the surgical sites. The defects were debrided of the granulomatous tissue, the root surfaces instrumented and conditioned with 4 one-minute applications of 50 mg/ml of tetracycline. The barrier membranes were adapted to cover the defects and the flaps replaced. The postsurgical healing was uneventful and similar in both treatment modalities.

RESULTS

Twenty-three sites were surgically re-entered 6 months from the time of the initial surgery. The deepest probe depth for each site was used for statistical analysis. There was a mean relative attachment gain of 2.58+/-1.90 mm for the collagen, and 2.77+/-2.13 mm for the copolymer. There was a decrease in probing depth of 3.27+/-1.91 mm and 0.69+/-1.35 mm of recession for the collagen. The PGA/PLA copolymer had 3.55+/-2.47 mm reduction in probe depth and 0.78+/-1.14 mm of recession.

CONCLUSIONS

The data indicated the bioabsorbable collagen and copolymer membranes resulted in comparable results. A larger sample size would be necessary to determine if one membrane was superior to the other.

Prevalence and serotyping of Porphyromonas gingivalis in an Indonesian population

In this study, the prevalence and serotype distribution of Porphyromonas gingivalis in an Indonesian population (n=158) is described. The relationship between subgingival P. gingivalis and periodontal attachment loss was investigated. The serotype distribution and periodontal parameters were studied. Serotyping was also used to study person-to-person transmission between siblings and between spouses. Approximately 50% of the subjects had periodontal attachment loss > or =3 mm at 1 or more recorded sites. The population was divided into 2 subgroups based on the presence or absence of P. gingivalis. No differences in plaque index, pocket depth, clinical attachment loss, bleeding upon probing, % of sites with > or =3 mm clinical attachment loss and % of sites with probing pocket depth > or =5 mm, were observed between both sub-populations. All known 6 capsular serotypes were found in the study population, with the exception of the K1 type. Detection of 1 of the known P. gingivalis serotypes was not related with the amount of clinical attachment loss. In 3 out of 29 sibships with more than one member positive for P. gingivalis, an identical P. gingivalis serotype was found. None of the 15 couples in the study shared an identical P. gingivalis serotype, indicating that transmission is probably not a common phenomenon in this population.

Gingival crevicular fluid osteocalcin in adult periodontitis

This study aimed to detect the levels of osteocalcin in gingival crevicular fluid (GCF) from healthy (< or =3 mm sulcus depth and non-bleeding) and diseased sites (> or =6 mm probing depth and bleeding) in subjects with adult periodontitis, in order to further investigate its potential as a possible marker of the disease process. Periodontal probing depths, attachment levels and gingival indices were recorded from one healthy and one diseased site in each of 20 subjects with adult periodontitis. Both GCF accumulated in the periodontal pocket or sulci and GCF flowing into the periodontal pocket or sulci over a three-minute interval were sampled. The amounts of osteocalcin in each GCF sample was determined using immunoassays. A mean of 2.34 ng/site (2.7 microg/ml) osteocalcin was found at diseased sites and a mean of 2.47 ng/site (5.47 microg/ml) was found at healthy sites for the accumulated GCF collection method. A mean of 0.17 ng/ site (2.17 microg/ml) osteocalcin was found at diseased sites and a mean of 0.14 ng/ site (1.85 microg/ml) at healthy sites for the flow method of GCF collection. There were no statistically significant differences between osteocalcin levels in diseased and healthy sites in subjects with adult periodontitis.

The use of a bovine bone mineral in periodontal osseous defects: case reports

This article reviews the clinical and radiographical results of 12 periodontal patients treated with a bovine bone graft, Bio-Oss. Thirty-two periodontal intrabony osseous defects of various sizes and morphology were surgically treated and evaluated at 6 months. The patients responded well to the use of the bovine bone mineral with good tissue response and an improvement of the intrabony defects. There was an overall mean probing pocket reduction in the deepest sites of 2.34 mm (S.D. +/- 1.59) and a mean gain in probing attachment levels of 1.84 mm (S.D. +/- 1.09). There was a difference in the sites treated with the bovine bone alone compared to sites treated with the bone mineral and barrier membranes, but these differences were not significant. These preliminary findings seem favorable for bovine bone mineral as an alternative graft material to allogenic bone grafts from human tissue banks in treating intrabony defects.

A clinical comparison of the new attachment obtained by guided tissue regeneration and coronally positioned flap techniques in the management of human molar furcation defects

The present clinical trial was designed to evaluate the regenerative potential of the periodontal tissue in Class II furcation defects in mandibular molars using reconstructive surgery based on the guided tissue regeneration (GTR) technique versus the coronally positioned flap (CPF) technique. After the completion of the initial phase of therapy and four to six weeks healing period, 20 furcation-involved molars were examined for baseline data which included plaque index, gingival condition, probing depth (PD), probing attachment level (PAL-V, PAL-H) and radiographs. All parameters were reexamined after three, six and twelve months of healing, except PD, PAL-V and PAL-H which were not measured at three and six months. A nonparametric analysis was used. The study showed that there were no significant differences in the mean baseline measurements between the treatment groups. After 12 months following surgical treatment, both GTR and CPF procedures showed gains in new clinical attachment levels. When comparing parameters between the two surgical procedures, GTR molars showed significantly more improvement in probing depth as well as vertical and horizontal attachment level of the interradicular osseous defect than did the CPF molars (p < 0.05). About 80 per cent of the sites treated with the GTR technique showed complete clinical resolution of the furcation problem. CPF therapy reached the same Treatment goal in about 50 per cent of the cases which were treated. Guided tissue regeneration appeared to be more effective in promoting regeneration than the coronally positioned flap.