Healing after treatment of periodontal intraosseous defects. IV. Effect of a non-resective versus a partially resective approach

Clinical and radiographic evaluation of Bio-Oss granules and Bio-Oss Collagen in the treatment of periodontal intrabony defects: a retrospective cohort study

OBJECTIVE

This retrospective study aimed to analyze the clinical efficacy of two regenerative surgical methods - Bio-Oss granules combined with barrier membranes and Bio-Oss Collagen alone - and to help clinicians achieve better periodontal regeneration outcomes in the specific periodontal condition.

METHODOLOGY

Patients who underwent periodontal regeneration surgery from January 2018 to April 2022 were retrospectively screened, and their clinical and radiographic outcomes at 6 months postoperatively were analyzed. The probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival recession (GR), distance from the cemento-enamel junction to the bottom of the bone defect (CEJ-BD), and depth of intrabony defects (INFRA) were recorded before the operation (T0) and 6 months after it (T1), and subsequently compared.

RESULTS

In total, 143 patients were included - 77 were placed in the Bio-Oss group and 66 were placed in the Bio-Oss Collagen group. All indicators, including PD and CAL at T1, showed significant differences compared to baseline, for both groups (P<0.001). PD reduction was greater in the group receiving the Bio-Oss Collagen treatment (P=0.042). Furthermore, in cases when the baseline PD range was 7-11 mm and the age range was 35-50 years, PD reduction was more significant for patients receiving the Bio-Oss Collagen treatment (P=0.031, 0.023). A linear regression analysis indicated that postoperative PD and CAL were positively correlated with baseline values, and that the efficacy tended to decrease with increasing age.

CONCLUSION

Both the use of Bio-Oss Collagen alone and the use of Bio-Oss granules combined with barrier membranes resulted in significant effects in the treatment of periodontal intrabony defects. The Bio-Oss Collagen treatment generated more improvements in PD than the Bio-Oss granules combined with barrier membranes, particularly within the baseline PD range of 7-11 mm and the 35-50 years age group. Additionally, age was the main factor influencing the effectiveness of regenerative surgery for intrabony defects: older individuals exhibited fewer improvements.

Surgical Treatment of Periodontal Intrabony Defects with Calcium Sulphate in Combination with Beta-Tricalcium Phosphate: Clinical Observations Two Years Post-Surgery

The study was designed to evaluate the clinical outcome of a composite material, beta-tricalcium phosphate in combination with calcium sulphate, in the treatment of periodontal intrabony defects. The combination of these materials is believed to aid in guided tissue regeneration owing to their properties. A total of 47 teeth with intrabony defects in 26 periodontitis patients were treated with Fortoss® Vital (Biocomposites, Staffordshire, UK). Clinical parameters were evaluated which included changes in probing depth, clinical attachment level/loss and gingival recession at the baseline and 2 years postoperatively. The mean differences in measurements between the baseline and 2 years postoperatively were a reduction of 2.07±1.14 mm (p=0.000) in case of probing depth and a gain of 1.93±1.36 mm (p=0.000) in clinical attachment level; but an increase of 0.14±0.73 mm (p=0.571) in gingival recession. The study results show that the treatment with a combination of beta tricalcium phosphate and calcium sulphate led to a significantly favorable clinical improvement in periodontal intrabony defects 2 years after the surgery.

Geometric alignment and chromatic calibration of serial radiographic images

OBJECTIVE

To develop software for automated registration and intensity calibration of serial dental radiographs for the analysis of longitudinal changes in bone density.

METHODS

Serial dental radiographs were acquired using a positioning device designed to minimize projection divergence. Each radiograph included an image of a standardized aluminium wedge. The radiographs were scanned on a flatbed scanner (AGFA Duo Scan) with a spatial resolution of 300 dpi, and pixel intensity coded in 16-bit grey scale. The intensity was calibrated using serial images of selected areas with defined thickness of the aluminium wedge. A robust B-splines multiresolution registration algorithm was implemented to overcome the acquisition misalignment. Radiographs, taken before and after periodontal therapy, were subtracted to assess bone density evolution.

RESULTS

The intensity calibration decreased the maximum intensity variations between serial radiographs from 30+/-17% to 1+/-1% (mean+/-standard deviation), and improved the visual comparison between the radiographs. The registration stage allowed correcting the misalignment of the radiographs on the scanner screen and superimposing the radiography contents. The observed residual motion was about 0.02+/-0.01 mm.

CONCLUSION

Very user-friendly software was developed. The manipulator needs to scan the radiographs only one time. The software performs all subsequent processing steps.

Subperiosteal and intraosseous connective tissue grafts for pocket reduction: a 9- to 13-year retrospective case series report

BACKGROUND

Recent histological evidence has documented that grafted palatal connective tissue is capable of forming a new attachment to previously exposed roots in the treatment of gingival recession. No clinical studies have tested the ability of connective tissue that has been implanted beneath the periosteum into periodontal osseous defects to reduce probing depth and increase clinical attachment levels. This study reports the long-term clinical effect of subperiosteal and intraosseous connective tissue grafts on deep periodontal pockets.

METHODS

Connective tissue (CT) grafts were placed in 32 periodontal pockets on 27 patients. Grafts were classified into 3 groups. Type I grafts had 50% or more vascular surface contact and were < or = 2.5 mm thick. Type II grafts had 50% or more contact but were > 2.5 mm thick, and Type III grafts had less than 50% vascular contact regardless of thickness. Twelve of 14 Type I sites, 9 of 15 Type II sites, and 3 of 3 Type III sites were analyzed 9 to 13 years following treatment.

RESULTS

Clinical attachment level change differed significantly between the graft types on survivor teeth (P < 0.05): Type III had 2 mm loss (95% confidence interval [CI]: 0.4 to 3.6), while Type II and Type I grafts had a 2.7 mm gain (95% CI: 2.0 to 3.4) and 4.3 mm gain (95% CI: 3.3 to 5.2), respectively. Similar substantial differences were presented for changes in probing depth and recession.

CONCLUSIONS

This long-term (9 to 13 years) retrospective case-series analysis suggests substantial improvements in periodontal clinical measures for Type I CT grafts in deep periodontal pockets. Randomized trials are required to evaluate this promising procedure.

Subperiosteal connective tissue grafts for pocket reduction and preservation of gingival esthetics: a case report

BACKGROUND

Clinical studies and recent histological evidence following mucogingival surgery for the treatment of gingival recession have documented that when closely adapted to a previously exposed root surface, connective tissue is capable of forming a new attachment. Despite these findings, no clinical tests have been conducted to examine the ability of connective tissue to reduce probing depth (PD) and increase clinical attachment levels (CAL) when it is implanted into periodontal osseous defects. The purpose of this paper is to report the clinical results on a patient following 2 subperiosteal connective tissue grafts.

METHODS

Subperiosteal connective tissue grafts were placed in 2 sites of periodontal bone loss and deep pocketing in one patient. Following flap reflection and root preparation, a connective tissue graft 1.5 to 2.0 mm in thickness was draped and sutured over each osseous defect and then completely covered by the external flap.

RESULTS

Ten months following subperiosteal connective tissue grafting, tooth #7 had 4 mm of CAL gain. Tooth #10 had 3 mm of CAL gain 8 months postoperatively. Both teeth had 1 mm gain in gingival recession. Both teeth probed 3 mm postoperatively.

CONCLUSIONS

When connective tissue was grafted into 2 periodontal osseous defects, there were significant reductions in probing depth and gains in CAL. There was minimal postoperative gingival recession. The new clinical attachment gain remained stable for 8 to 10 months following subperiosteal connective tissue grafting.

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.

Generalizability of the added benefits of guided tissue regeneration in the treatment of deep intrabony defects. Evaluation in a multi-center randomized controlled clinical trial

BACKGROUND

Several studies have shown that GTR therapy of intrabony defects results in significantly better outcomes than access flap alone. Most of the available data, however, have been produced in highly controlled research environments by a small group of investigators. Generalizability of results to different clinicians and different subject populations has not been evaluated so far.

METHODS

This parallel group study involved 143 patients recruited in a practice-based research network of 11 offices in 7 countries. It was designed to evaluate: 1) the applicability of the documented added benefits of GTR in the treatment of intrabony defects to different populations, and 2) the generalizability of the expected results to different clinicians. GTR was compared to access flap alone. Defects, one in each patient, were accessed with a previously described papilla preservation flap in both the test and control group. In addition, GTR sites received application of a bioabsorbable poly-D,L-lactide-co-glycolide membrane. A stringent plaque control regimen was enforced in all patients during the 1-year observation period. Outcomes included gains in clinical attachment (CAL) and reductions in probing depth.

RESULTS

Observed gains in CAL were 2.18 +/- 1.46 mm for access flap and 3.04 +/- 1.64 mm for the GTR-treated group. The treatment-associated difference was statistically significant (P = 0.03) after correcting for both center effect and defect anatomy. Among the various centers, a 1.73 mm difference in CAL gain was observed. This is a clinically relevant amount, which underlines the significance of center variability in the outcome of periodontal surgical procedures. A frequency distribution analysis of the obtained CAL gains indicated that GTR treatment of deep intrabony defects decreased, with respect to the access flap control, the probability of obtaining only a modest attachment gain at 1 year. Conversely, CAL gains of 4 mm or more were observed in more than 40% of GTR-treated defects and in less than 20% of the controls (P < 0.0001).

CONCLUSIONS

These data indicate that GTR therapy of deep intrabony defects performed by different clinicians on various patient populations resulted in both greater amounts and improved predictability of CAL gains than access flap alone.

Clinical comparison of bioabsorbable barriers with non-resorbable barriers in guided tissue regeneration in the treatment of human intrabony defects

The purpose of the study was to compare the effects of guided tissue regeneration (GTR) with expanded polytetrafluoroethylene (ePTFE) non-resorbable barriers and polylactic acid bioabsorbable barriers in humans with intrabony defects due to periodontitis. Ten patients presented with 2 intrabony defects each. Mucoperiosteal flaps were performed. One of the defects was randomly assigned for placement of the ePTFE barrier over the roots and alveolar bone and the other defect with placement of the polylactic acid barrier. A minimum of 9 months after barrier placement, surgical reentry was performed. The data were evaluated by the Wilcoxon matched-pairs signed-ranks test and the Fisher exact test. Treatment with both types of barriers produced significant changes from baseline for all parameters, except in the ePTFE group for the amount of bony crest resorption (P = 0.055) and in the polylactic acid group for increased recession (P = 0.109). The results showed no significant differences between the barriers for any parameters: probing depth reduction (polylactic acid 2.60 +/- 1.90, ePTFE 2.80 +/- 1.40; P = 1.000); attachment gain (polylactic acid 1.40 +/- 1.43, ePTFE 1.90 +/- 1.29; P = 0.336); increased recession (polylactic acid 0.80 +/- 1.40, ePTFE 1.10 +/- 0.99; P = 0.531); amount of vertical bone fill (polylactic acid 1.60 +/- 1.84, ePTFE 2.00 +/- 2.49; P = 0.984); bony crest resorption (polylactic acid -1.30 +/- 1.06, ePTFE -1.30 +/- 1.63; P = 1.000); depth of bony defect reduction (polylactic acid 2.90 +/- 1.20, ePTFE 3.30 +/- 1.70; P = 0.750); width of bony defect reduction (polylactic acid 2.20 +/- 1.23, ePTFE 2.20 +/- 1.23; P = 0.875); or volumetric changes (polylactic acid 33.50 +/- 19.70 microl, ePTFE 34.00 +/- 18.40 microl; P = 0.750).

Retrospective analysis of factors related to clinical outcome of guided tissue regeneration procedures in intrabony defects

The purpose of this retrospective study was to determine factors affecting clinical outcome of guided tissue regeneration (GTR) in the treatment of intrabony periodontal defects. 38 patients each contributing 1 isolated intrabony defect treated with GTR were included in this analysis. Patient and defect characteristics, and defect-specific recordings relative to clinical outcome 6 months postsurgery were assessed. GTR treatment resulted in clinically and statistically significant improved probing depths (PD), clinical attachment levels (CAL), and probing bone levels (PBL). Presurgery PD and PBL were of predictive value for CAL gain and PBL gain, respectively. CAL and PBL gain did not correlate to defect depth or configuration. Cigarette smoking exhibited a highly significant negative correlation to parameters of clinical outcome.

Factors affecting the healing response of intrabony defects following guided tissue regeneration and access flap surgery

Identification and control of significant factors determining clinical outcomes is of paramount importance to improve expected results of a variety of therapeutic procedures. The aim of this investigation was to identify, with a multivariate approach, factors associated with healing outcomes of 3 periodontal surgical procedures in deep intrabony defects. 45 patients with evidence of deep intrabony defects were randomly assigned to 3 treatment groups: access flap (group C), conventional guided tissue regeneration (GTR) with non-resorbable expanded polytetrafluoroethilene (ePTFE) membranes (group B), and GTR with self supporting membranes combined with the modified papilla preservation technique (group A). In both GTR procedures, membranes were positioned coronal to the interproxymal alveolar crest. Primary outcome variables (i.e., probing attachment level gains at 1 year and the amount of newly formed tissue present at membrane removal) were explained in terms of a series of patient, defect morphology and surgical factors, using a multivariate approach. Highly significant treatment effects were observed, indicating that the 3 tested therapeutic modalities resulted in significant differences in primary outcome variables. Detailed analysis assessing the significance of the tested factors in determining the healing outcomes following each procedure was performed with a stepwise elimination approach of non-significant factors. The results indicated that: (i) the need to create and maintain space should be a key objective of regenerative approaches based upon the principles of guided tissue regeneration; (ii) control of patient's oral hygiene and residual periodontal infection in the oral cavity are strongly associated with clinical outcomes of both regenerative and conventional surgical procedures and should receive proper attention.

Periodontal regeneration of human intrabony defects with bioresorbable membranes. A controlled clinical trial

The purpose of this controlled clinical trial was to compare the clinical efficacy of 3 treatment modalities in the treatment of deep interproximal intrabony defects. Thirty-six (36) defects in 36 patients were randomly assigned to 1 of 3 treatment groups by blocking to prognostic variables. The test was treated with bioresorbable membranes positioned coronal to the interproximal bone crest; the second group (membrane control) was treated with conventional non-resorbable (ePTFE) barrier membranes applied coronal to the alveolar crest; the third group (flap Control) was treated with an access flap procedure (MWF). No differences were observed in terms of baseline oral hygiene and defect characteristics among the 3 groups, indicating that the blocking approach was effective. A stringent infection control program was enforced for 1 year. The results indicated that: 1) at 1 year all treatment modalities resulted in clinically significant improvements in clinical attachment levels (CAL) and reductions in probing depths; 2) a statistically significant treatment effect (P < 0.0001, ANOVA) was observed comparing the test (4.6 +/- 1.2 mm), the membrane control (5.2 +/- 1.4 mm), and the flap control groups (2.3 +/- 0.8 mm) in terms of CAL gain; 3) differences in terms of CAL gain between the test (bioresorbable) and the membrane control (ePTFE) groups were not statistically significant (P = 0.19, t-test); 4) both the test and the membrane control groups gained significantly more CAL at 1 year than the MWF group (P < 0.0001, t-test). CAL gains > or = 4 mm were observed in 83.3% of cases in both GTR groups, while CAL gains of this magnitude were not detected in the MWF group. We concluded that clinically significant CAL gains can be obtained with GTR procedures using both bioresorbable and non-resorbable membranes. Patients' morbidity, however, was lower in the group treated with bioresorbable membranes.

Effect of gingival wall on resistance to probing forces

This study was conducted to determine whether the gingival tissue lateral to the periodontal sulcus contributes resistance to the advancement of a periodontal probe tip into the sulcus under different applied pressures. An electromechanical device was used to advance a probe tip 0.6 mm in diameter into the facial sulcus at a constant speed until resisting forces of 0.70 N were encountered. The device registered the resisting force and probe advancement simultaneously. The gingiva of all 2nd incisors, 2nd premolars, and 1st molars of 4 young adult male beagle dogs were tested. After the first measurement, the buccal gingiva of experimental sites were incised mesiodistally from the gingival margin to the alveolar crest and the sulcus was reprobed. 2 experimental and control quadrants were selected randomly resulting in 6 sets of both experimental and control data from each animal. The data were analyzed with analysis of variance. The analysis demonstrated significant variation from site to site, and dog to dog; therefore, only changes between the 1st and 2nd probings at the same sites could be compared. Less variability of probing distance in different animals occurred at higher forces; however, the incision had a significant effect on probing distance at these forces. The pressure at which probing distance had less variability among animals and least affected when the gingival sulcular wall was incised was estimated to be 106 N/cm2. This corresponds to 30 g force on the 0.6 mm diameter probe.

Clinical evaluation of natural coral and porous hydroxyapatite implants in periodontal bone lesions: results of a 1-year follow-up

This study examines the suitability of 2 bone graft substitutes, natural coral skeleton (NCS) and porous hydroxyapatite (PHA) for treating periodontal bone defects in human subjects, and compares them to debridement alone (DEBR). A total of 30 sites in 10 patients were treated. Measurements were made before treatment and during surgical reexamination 12 months after treatment on lesions filled with NCS (10 sites), PHA (10 sites), or DEBR (10 sites). There was no significant difference in the use of NCS or PHA for 1, 2 wall, or combined defects for the group of parameters measured in this study (clinical probing depth, clinical attachment, gingival recession, bone fill, % bone fill, and crest remodelling). Statistical analysis (Wilcoxon non-parametric test for paired values and ANOVA for repeated measurements) revealed the beneficial effects of using each the biomaterials (57.4% for NCS, 58.1% for PHA, p < 0.86) as opposed to simple debridement (22.2%; p < 0.002; p < 0.004).

Periodontal regeneration of human intrabony defects with titanium reinforced membranes. A controlled clinical trial

The purpose of this controlled clinical trial was to compare the clinical efficacy of 3 treatment modalities in the treatment of deep interproximal intrabony defects. Forty-five (45) defects in 45 patients were randomly assigned to 1 of 3 treatment groups by blocking to prognostic variables. The test group was treated with titanium reinforced membranes positioned just apical to the cemento-enamel junction and the modified papilla preservation technique; the second group received conventional expanded polytetrafluoroethylene (ePTFE) barrier membranes applied at the alveolar crest; the third group was treated with an access flap procedure. The groups were well balanced with respect to all prognostic variables. During the 1-year observation period, patients were subjected to a stringent infection control program including: professional tooth cleaning every week for the first 6 weeks (all groups) and in the 4 weeks following membrane removal (guided tissue regeneration groups), then at monthly intervals (all groups). The results indicated that: 1) all treatment modalities resulted in clinical and statistically significant improvements in clinical attachment level (CAL) and probing depths (PD) at 1 year; 2) a significantly greater amount of CAL gain (P = 0.0003, analysis of variance) was observed in the test group (5.3 +/- 2.2 mm) with respect to both the ePTFE group (4.1 +/- 1.8 mm) and the flap control group 2.5 +/- 0.8; 3) in the test group the 1 year CAL (4.7 +/- 1.8 mm) was located more coronally than the baseline position of the interproximal alveolar crest (5.9 +/- 2 mm; P = 0.003, t test).(ABSTRACT TRUNCATED AT 250 WORDS)

No detrimental effect of fibrin glue on the regeneration of intrabony defects. A controlled clinical trial

This controlled clinical trial evaluated the potential of fibrin glue as a biological carrier to locally deliver guided tissue regeneration (GTR) modulators, 2 controlateral, morphologically similar defects were selected in each of 11 patients and randomly assigned to the test (teflon membrane and fibrin glue) and the control treatment (teflon membrane alone). Outcomes were assessed at membrane removal as newly formed granulation tissue and at the 1-year follow-up in terms of changes in probing attachment level, probing pocket depth, recession of the gingival margin, probing bone levels and percentage of fill of the intrabony defects. Data confirmed that GTR treatment of deep intrabony defects results in clinically and statistically significant improvements of the clinical parameters. No significant differences, however, were evidenced between the test and the control treatments. It is suggested that, since fibrin glue did not show detrimental effects on GTR, it could be applied as a biological carrier for the delivery of GTR enhancers into the surgical wound.

The modified papilla preservation technique. A new surgical approach for interproximal regenerative procedures

A modification of the papilla preservation technique has been applied to achieve primary closure of the interproximal tissue over barrier membranes placed coronal to the alveolar crest. Fifteen patients with deep intrabony interproximal defects were treated. Defects had a probing attachment level loss of 9.9 +/- 3.2 mm and a recession of the gingival margin of 1.7 +/- 1.6 mm. The depth of the intrabony component was 5.5 +/- 2.9 mm; while the suprabony component was 5.9 +/- 2.0 mm. Titanium-reinforced teflon membranes were placed 1.3 +/- 0.7 mm from the cemento-enamel junction, 4.5 +/- 1.6 mm coronal to the interproximal alveolar bone crest. Primary closure over the interproximal portion of the membrane was obtained in 93% of cases. In 73% of the cases complete coverage of the membrane was maintained until its removal at 6 weeks. These data indicate that the modified papilla preservation technique can be successfully applied to obtain primary closure of the interdental space in regenerative procedures with barrier membranes.

Histological location of a standardized periodontal probe in man

The purpose of this study was to locate the position of the periodontal probe tip using a pressure of 126 N/cm2 (force of 0.30N using a round periodontal probe tip with a diameter of 0.55 mm). The influence of gingival inflammation on this position was also studied. Subjects with three levels of periodontal health and disease were entered into the study and each contributed one experimental tooth. At each site a standardized probing system was used to place a probe into a clinical pocket. The probe tip was luted to the test tooth surface. The tooth with its gingival tissue and probe tip was extracted, fixed, and processed for histological measurements. Distances in mm were obtained from the cemento-enamel junction (CEJ) to the probe tip, to the base of the crevice/pocket, and to the most coronal connective tissue attachment. Analysis of the data indicated that clinical inflammation was not a factor in the placement of the probe tip at crevice/pocket's landmarks relative to the CEJ; however variability of probing may have caused the non-significance. The probing system placed the probe tip 0.66 mm apical to the base of the crevice/pocket and 0.06 mm coronal to the most coronal connective tissue attachment. These conclusions corroborated the results of the previous study in dogs which predicted probe placement of 0.44 mm apical to the base of the crevice using the standardized pressure of this probing system.

The effect of post-surgical flap placement on probing depth and attachment level: a 2-year longitudinal study

Postsurgical flap placement might affect the outcome of the operative procedure. Modified Widman flap surgery with primary closure and flap approximation (usually away from the bone crest) and apically positioned flap surgery with near crestal bone positioning are both widely used in surgical periodontal treatment. Several comparative investigations have studied these modalities, however, none have been able to show conclusively that either is superior to the other. The purpose of this longitudinal study was to explore the optimal postsurgical flap placement in respect to final probing depth and changes in clinical attachment level. Following routine hygienic phase of treatment, 12 subjects (186 teeth) with adult periodontitis received surgical periodontal treatment. Prior to the flap surgery, probing depth and clinical attachment level were recorded. Sounding depth measurements were taken to record postoperative flap placement. Patients were placed on a 3-month maintenance program. Probing depth and clinical attachment level were again measured at 2 years postoperatively and compared to baseline measurements. An overall positive correlation (R = 0.43; P = 0.0248) was found between immediate postoperative sounding measurements and probing depth after 2 years. Conversely, attachment level changes over the 2-year period showed only weak inverse correlation (R = 0.27; P = 0.0121) with sounding depth measurement immediately postsurgically. Sites where postoperative sounding depth were < or = 3 mm had a mean probing depth (2.52 mm) which was significantly (P < 0.001) smaller compared to sites with sound depth > or = 4 mm (3.58 mm). Changes in clinical attachment level varied between sites and sounding depth groups; however, none of these differences were statistically significant. Based on our findings it is suggested that following periodontal flap surgery, in those cases where minimal probing depth is desired, the flap be secured to the underlying structures at or slightly coronally to the bone crest (< or = 3 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of periodontal furcation defects. Coronally positioned flap with or without citric acid root conditioning in class II defects

A total of 27 mandibular, buccal class II furcation defects were treated in 16 subjects using a coronally positioned flap procedure, with or without citric acid conditioning of the root surfaces. The effect of the therapies was evaluated from a series of soft and hard tissue measurements. Mean improvements were slightly greater for acid treated than for non-acid treated defects. However, none of the mean differences reached statistical significance, indicating that citric acid conditioning may not be a necessary part of the regenerative, coronally positioned flap procedure in mandibular furcations.

Remodelling of periodontal tissues adjacent to sites treated according to the principles of guided tissue regeneration (GTR)

The aim of the present study was to assess the remodelling of alveolar bone adjacent to periodontal sites following therapy according to the principles of guided tissue regeneration (GTR) using computer-assisted densitometric image analysis (CADIA), and to compare the radiographic results to traditional clinical parameters. As required for digital subtraction analyses, periodically reproducible radiographs were obtained using a modification of the Rinn System and individual acrylic bite blocks for periodical identical radiographs. Ideally, a digital subtraction image from a site where absolutely no change in density had occurred would show a perfect cancellation of the structures. An average grey level value of 128 (the middle of the digitizer grey level range set by software) would show up at each pixel. Areas with grey levels < 128 in the subtraction image would indicate loss in density and grey levels > 128 would indicate increase in density. Within the subtraction images, areas were defined using the cursor to draw "regions of interest" (ROI) projected on the bony defect exposed to GTR covering the crestal bone as well as the region of potential "bonefill". The mean, median, the standard deviation and range of the grey levels of pixels within a particular ROI were calculated. Similarly sized ROI were drawn in bone areas not exposed to the GTR procedure serving as controls. The differences in the mean grey levels of all pixels within a particular ROI between the baseline, 3 and 12 months images were calculated for documentation of gain or loss in density. From 14 patients, standardized radiographs were available from baseline, 3 months and 12 months postsurgically, depicting one infraosseous defect before and after treatment according to the principles of GTR. The densitometric changes observed in these defects were compared to the clinically assessed changes measured at the site with the deepest baseline pocket depth. A mean clinical attachment gain of 2.36 mm after 3 and 3.22 mm after 12 months was measured. This was associated with a mean reduction in the PPD amounting to 3.36 mm and 3.79 mm, respectively. The changes in the level of the FGM were rather small considering the deep original mean PPD of 7.07 mm. Over the first months, a mean recession of 1.14 mm was observed which was followed by a coronal displacement of 0.43 mm. With respect to the remodelling of the alveolar bone adjacent to the defects assessed by means of CADIA, the most pronounced changes occurred when comparing the baseline to the 12 months radiographs.(ABSTRACT TRUNCATED AT 400 WORDS)

Depth-force patterns of periodontal probing. Attachment-gain in relation to probing force

It was the purpose of this study to determine whether probing force had an influence on the amount of clinical attachment-gain assessed after treatment by scaling and rootplaning. A probing device was constructed which allowed simultaneous monitoring of probing force and probe penetration and which standardized the insertion pathway for repeated measurements. In 10 periodontal patients, 2 deep pockets were selected which were measured before and after periodontal treatment by scaling and root-planing. Depth-force plots were compared by superimposition. Depth values were determined at 5 different force levels (0.25, 0.50, 0.75, 1.00 and 1.25 N) on each plot and changes of clinical attachment levels were calculated. A significant relationship was seen between probing force and attachment level. The values obtained with 0.25 N were significantly different from the values obtained with higher forces (p less than 0.001). Slight, but non-significant differences were noted in the amount of attachment-gain obtained at the 5 force levels. At a probing force level of 0.25 N, there was 0.80 mm mean attachment gain. With 0.50 N, there was a gain of 0.70 mm; with 0.75 N the gain amounted to 0.67 mm in mean. At 1.00 N and at 1.25 N, a gain of 0.66 mm was recorded.

Comparison of photodensitometric with high-resolution digital analysis of bone density from serial dental radiographs

Photodensitometry is known to provide high spatial resolution and continuous measurement of optical density for the analysis of dental radiographs, whereas digitization allows powerful image manipulations but, when using conventional video cameras, gives less spatial resolution and fewer grey levels. The aim of this study was therefore to develop a technique of high-resolution digital analysis for the measurement of bone density following the same principles as those of photodensitometry and based upon the use of a CCD Scanner Camera which provides up to 4096 grey levels and a spatial resolution of 4096 x 4096 pixels. Twenty-four zones were analysed with both techniques in five serial dental radiographs taken before and after periodontal therapy in eight patients. Statistical comparison of the results obtained by digital analysis and photodensitometry shows that the two techniques have the same accuracy.

Short-term effects of initial periodontal therapy (hygienic phase)

The aim of the present study was to evaluate the effect of non-surgical periodontal therapy on probing pocket depths and probing attachment levels using a patient group with moderate to advanced periodontitis. 68 patients with moderate to advanced periodontitis underwent hygienic phase therapy including oral hygiene instructions, scaling and root planing and elimination of plaque retentive factors. Assessments of the plaque control record (PCR), bleeding on probing (BoP), probing depths and probing attachment levels were performed at baseline examination and 3 to 5 months following active treatment. The measurements were obtained at 4 interproximal aspects of each tooth with a thin calibrated probe. Mean BoP values decreased from 63.2 +/- 21.9% at baseline to 16.6 +/- 7.3% after therapy, and mean PCR decreased from 78.6 +/- 16.4% to 12.7 +/- 7.1%, respectively. A reduction in mean probing pocket depth from 3.96 +/- 1.39 mm at baseline to 3.30 +/- 1.16 mm after therapy was noted. Sites with initial probing depths of 1-3 mm showed no change, sites with initial values of 4-6 mm revealed a reduction of 1.03 +/- 1.04 mm, while initial pockets of 7-9 mm decreased in depth by 2.28 +/- 1.62 mm. A gain in the mean probing attachment level from 4.16 +/- 1.80 mm to 3.74 +/- 1.71 mm was observed as a result of treatment. The group with the shallow initial probing depths of 1-3 mm showed no alteration in probing attachment level. Pockets with baseline values of 4-6 mm showed gain of clinical attachment of 0.69 +/- 1.43 mm. The greatest gain in clinical attachment of 1.51 +/- 1.75 mm was obtained in sites with initially deep pockets of 7-9 mm. From the results of this study, it can be concluded that non-surgical periodontal therapy is an effective means to reduce probing pocket depths and to improved clinical attachment levels in patients with moderate to advanced periodontitis.

Increase of interproximal bone density after subgingival instrumentation: a quantitative radiographical study

Ten interproximal sites, with periodontal pockets deeper than 5 mm and showing loss of bone on standard dental radiographs, were treated by subgingival instrumentation in 10 patients properly motivated and given thorough hygiene instructions. The index of gingival inflammation, the plaque index, the degree of mobility, the depth of the pockets, and the loss of attachment were measured before starting the treatment, and 2 months, 6 months, and 1 year after treatment. Standardized reproducible radiographs of the 10 sites were taken by using a recently developed paralleling instrument before treatment, immediately after and 2 months, 6 months, and 1 year afterwards. The density of the interdental bone was measured on the radiographs by a computer assisted densitometric technique at three levels of the interdental septum: the most occlusal or "superficial" level; the "deep" level, arbitrarily chosen 1.5 mm below; and the "control" level, in a much deeper area of interproximal bone. As further control, the density of the superficial crestal bone was also followed in 5 healthy untreated sites from 5 of the patients. As expected, a significant improvement of the clinical parameters was observed during the year following therapy. The results of the radiographical analysis showed statistically significant increases of both the superficial and deep average densities of interproximal bone at 6 months and 1 year after treatment. The superficial bone density was, on the average, 13% higher at 6 months and 16% higher at 1 year, as compared to that measured immediately after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of clinical and radiographic scoring methods before and after initial periodontal therapy

The purpose of the present study was to compare the determination of the attachment level by probing and by measuring bone heights prior to and after the completion of a hygienic phase of periodontal therapy. 68 patients with moderate to severely advanced periodontitis underwent initial (hygiene phase) therapy including scaling and root planing, oral hygiene instructions and the elimination of plaque retention factors. Measurements of pocket probing depths, probing attachment levels and the location of gingival margins in relation to the cemento-enamel junction were performed at 4 aspects of each tooth with a thin calibrated probe at a baseline examination and 3 to 5 months following treatment. During these 3 to 5 months, the patients were kept in a maintenance care program. On the full-mouth radiographs obtained at baseline, the distance from the cement-to-enamel junction to the marginal alveolar crest was measured in millimeters and as a % of the root length. Furthermore, a subgroup of 11 patients, who were scheduled for modified Widman flap procedures, received another full-mouth radiographic examination before the surgical treatment. In addition, the level of the alveolar crest was assessed with a periodontal probe during the surgical procedure. The comparison of the different clinical and radiographic parameters showed the best correlations between the various radiographic measurements of bone heights (r = 0.87; r = 0.86). Clinical measurements of probing attachment level and probing level of the alveolar crest revealed slightly weaker correlations (r = 0.72). When comparing radiographic bone heights with clinical measurements of probing attachment levels, the lowest correlations were found (r = 0.65; r = 0.61; r = 0.61).

Treatment of periodontal furcation defects. Coronally positioned flaps versus dura mater membranes in class II defects

Mandibular class II furcation defects in 19 subjects were treated using 2 different methods of wound closure. In 16 of the defects, the wound was closed with a coronally positioned surgical flap secured by crown-attached sutures. In 15 of the defects, a collagenous membrane (freeze-dried dura mater) was placed to cover the exposed defect, followed by suturing of the surgical flap at the level of the alveolar crest. After use of a coronally positioned flap, an average of 70% of the defect volume became filled with bone, with complete closure by bone fill for 9 of the 16 treated defects. After use of dura mater membrane, 38% of the defect volume was filled with bone, with complete bony closure for 3 of the 15 treated defects. The results following use of coronally positioned flaps support our previous findings and the potentials of this technique. The results following use of dura mater membranes, together with recently reported risk for spread of virus with dura implants, do not justify the use of dura mater for these regenerative purposes.

Relationship between the radiographic periodontal defect angle and healing after treatment

This study radiographically evaluated the correlation between the changes in alveolar bone level occurring in bony defects after periodontal therapy and the corresponding pretreatment defect angles. The defect angle was defined by the bony defect surface and the root surface. The changes were determined from identically exposed and processed radiographs obtained just prior to surgery and 15 to 18 months later. The defect angle was clearly correlated to the radiographic changes in alveolar bone level. Most defects with an angle less than 45 degree showed a gain of bone while defects with the largest defect angles showed a loss. In addition, defects on root surfaces without furcations showed better healing than defects associated with furcations.

Treatment of intraosseous periodontal defects with a combined adjunctive therapy of citric acid conditioning, bone grafting, and placement of collagenous membranes

A total of 25 proximal, intraosseous periodontal defects were treated in 21 adult patients. A 3-prong adjunctive, regenerative treatment approach was used. The treatment included (1) citric acid conditioning of the root surfaces, (2) grafting of particles of decalcified, freeze-dried homologous bone, and (3) placement of freeze-dried, homologous dura mater sheets between the replaced surgical flaps and the tooth surfaces. The results, as evaluated by probing attachment and probing bone level measurements, during 1 year of observation, demonstrated limited improvements of the treated defects. The limited results were similar to previous observations in our clinics following treatment of intraosseous defects using different treatment modalities. It appears that new treatment approaches need to be sought to accomplish clinically significant and predictable regeneration in proximal, intraosseous periodontal defects.

Treatment of periodontal furcation defects. (II). Bone regeneration in mandibular class II defects

A total of 30 mandibular, buccal class II furcation defects were treated in 22 subjects using a regenerative surgical therapy that included citric acid root conditioning and coronally positioned flaps secured by crown-attached sutures. In addition, grafts of freeze-dried, decalcified allogenic bone were placed in 16 of the 30 defects. The effect of the therapies was evaluated from a series of soft and hard tissue measurements. These measurements demonstrated notable improvement 12 months following therapy. On the average, 67% of the defect volume became filled with bone. 43% of treated defects were completely closed by bone fill. No difference was observed between defects treated with and without bone grafts.

Healing after treatment of periodontal intraosseous defects. VI. Factors influencing the healing response

84 periodontal intraosseous defects treated with mucoperiosteal replaced flap surgery and citric acid root conditioning were used to study the relationships between various defect characteristics and the healing response as expressed by change of probing attachment level, change of probing bone level and residual probing depth. More gains in probing attachment and probing bone levels were observed in deep defects than in shallower lesions. Other defect characteristics showed weak or no correlations to defect fill. The findings of this study seem to indicate that the outcome of treatment of intraosseous defects may be difficult to predict based upon evaluation of defect characteristics.

Healing after treatment of periodontal intraosseous defects. V. Effect of root planing versus flap surgery

The present study compared surgical therapy to root planing alone in the treatment of periodontal intraosseous defects. 25 defects in 14 patients were subjected to root planing only and another 25 defects in the same patients were surgically exposed and citric acid treated. The healing response was evaluated 6 months after treatment. The mean gain of probing attachment level was 0.8 mm in the root-planed defects as compared to 1.3 mm for the surgically exposed and acid-treated defects. The probing bone level improved an average of 0.2 mm for the root-planed areas as compared to 0.6 mm for the acid-treated defects. The mean preoperative probing pocket depths of 6.7 mm and 6.8 mm for the 2 groups were reduced to 5.2 mm and 4.1 mm, respectively. The differences in these parameters were statistically significant between the 2 groups. However, both groups demonstrated limited regeneration.