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Notes: Background: Intra-bony defects remain a significant therapeutic problem in periodontal therapy. Various non-surgical and surgical treatment modalities are being used. The long-term stability following treatment of intra-bony defects is poorly documented.〈section xml:id="abs1-2"〉〈title type="main"〉Objectives:To assess changes in intra-bony defects after either osseous surgery or open flap debridement in combination with grafting procedures with demineralized freeze-dried bone allografts (DFDBA).Method: Pre- and post-surgical computer digitized images of intra-oral radiographs from 60 patients who had received periodontal surgery to manage intra-bony defects were analyzed by linear measurements.Results: 36 patients were treated with osseous surgery and 24 had received flap procedures and grafting with DFDBA. Post-surgical radiographs were obtained on average after 4.8 years (SD±2.8) and after 9.6 years (SD±3.6). A minor mean bone fill of 0.0 mm (SD±0.8) for osseous surgery sites and 0.5 mm (SD±0.9) for DFDBA sites, was noticed, but this gain was within the margin of measurement errors. Osseous surgery and modified Widman flap procedures with DFDBA resulted in crestal resorption, on average 1.7 mm (SD±1.1) and 1.5 mm (SD±1.5) and remaining mean defect depth of 2.0 mm (SD±1.4) and 2.5 mm (SD±1.6), respectively.Conclusions: Bone changes following bone graft procedures with DFDBA did not differ from those following osseous surgery, and neither procedure resulted in defect resolution with bone fill. It was also concluded that over the study period, stable treatment results were obtained as a result of both osseous surgery and modified Widman flap procedures with adjunct DFDBA.

Notes: Aims: The objectives of the present, randomised clinical trial were (i) to evaluate the healing of periodontal intrabony defects at the distal aspect of mandibular 2nd molars using a resorbable polylactic acid (PLA) barrier and a non-resorbable polytetrafluoroethylene (e-PTFE) barrier and (ii) to compare the therapeutic effect of the bioresorbable versus the non-resorbable barrier.Method: 19 patients with intrabony defects distal to mandibular 2nd molars 〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:03036979:JCPE270507:ges" location="ges.gif"/〉4 mm (on radiographs) were included in the study. The defects all remained 5 years after surgical removal of impacted 3rd molars. Following flap elevation and defect debridement, the defects were randomly covered with, either a resorbable PLA or a non-resorbable e-PTFE barrier. Flaps were repositioned and sutured to completely cover the barriers. Treatment was evaluated clinically after 1 year by measurements of probing depth (PD), probing attachment level (PAL), and probing bone level (PBL) and radiographically by measurements of bone levels on computer digitised images of radiographs taken immediately before and 1 year post-surgery.Results: Both treatments resulted in significant PD reduction, PAL gain, and bone fill. The total PD reduction was 5.3±l.9 mm for the PLA treated sites and 3.7±l.7 mm for the e-PTFE treated sites (p〈0.05). The corresponding values for PAL gain were 4.7±0.7 mm and 3.6±1.7 mm (p〈0.05) and for PBL gain 5.1±1.2 and 3.3±2.0 mm (p〈0.05). Radiographic bone fill averaged 3.4±l.2 for the PLA and 2.0±1.6 mm for the e-PTFE barriers (p〈0.05). Radiographic bone level measurements were significantly smaller than the corresponding clinical measurements, indicating that radiographs tend to underestimate bone fill.Conclusions: GTR treatment of deep intrabony defects distal to mandibular second molars using resorbable PLA barriers resulted in significant PD reduction, PAL gain and bone fill at least equivalent to the results obtained using non-resorbable e-PTFE barriers.

Notes: Background, aims: This investigation was performed to assess longitudinal changes in periodontal bone height in an adult population over a period of 17 years.Methods: In 1973, a random sample of 1000 individuals aged 3–70 years in the city of Jönköping, Sweden, was examined clinically and radiographically to assess dental status and treatment needs. Out of the 574 dentate individuals 15–60 years, 433 accepted the invitation and were re-examined in 1989–91, 4 were edentulous and the study therefore finally included 429 dentate individuals. The examination included full mouth plaque and gingivitis scores and bone height measurements on full mouth intra-oral radiographs. All age groups except the youngest had very good oral hygiene with 50% or more having plaque and gingivitis scores below 20%.Results: From the age of 20, there was a general pattern of bone height reduction over time corresponding to an annual loss of around 0.1 mm. From the age of 30 years, about 80% of the population had one or more sites with bone loss of 10% or more. Very few individuals, about 5%, exhibited an individual mean bone loss of 2 mm or more. 17% had 〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:03036979:JCPE27009665:ges" location="ges.gif"/〉6 such sites indicating destructive periodontal disease. These individuals and sites could not be identified in advance based only on previous disease experience.

Notes: Background: Different types of barriers are used in guided tissue regenerative procedures.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:This prospective study compared resorbable citric acid ester softened polylactic acid membranes (RM) and non-resorbable expanded polytetrafluoroethylene (ePTFE) barriers (NRM) in GTR treatment of intrabony defects.Methods: 29 subjects were randomly assigned to the RM group or NRM group. Each patient received one GTR procedure. An open flap debridement (FD) was performed at another site 2 weeks later to evaluate healing potential. Clinical treatment outcomes were finally evaluated 12 months after surgery for changes of pocket depth PD, probing attachment level PAL, and probing bone level PBL, and radiographically for bone change using standardised radiographs.Results: No differences in healing patters after surgery were found between patients in the 2 study groups as evaluated from the FD surgical procedures. NRM treated sites showed less signs of post-surgical inflammation during the 1st 4 weeks of healing than did RM treated sites (p〈0.05). GTR-treated defects in the RM group, initially 7.0±2.2 mm deep, showed PD reduction of 3.3±2.2 mm, PAL gain of 2.4±1.8 mm, PBL gain of 2.4±3.7 mm (28%) and a radiographic bone fill of 2.3±2.4 mm. Defects treated with the NRM exhibited PD reduction of 3.1±2.1 mm, PAL gain of 2.4±0.8 mm, PBL gain of 2.2±1.7 mm (25%) and a radiographic bone fill of 3.3±2.2 mm. All improvements were statistically significant (p〈0.01) but there was no difference between RM and NRM treatments for any of the efficacy variables. The results of this study indicated that there was no clinically significant difference in treatment outcomes following GTR treatment of intrabony defects with citric acid ester softened polylactic acid membranes as compared to ePTFE barriers. The overall mean inter-proximal vertical bone defect fill at 12 months as assessed from intra-oral radiographs was 44% of the original mean defect depth.Conclusions: Thus, no clinically significant difference in treatment outcomes was observed following GTR treatment of intrabony defects with citric acid ester softened polylactic acid membranes or ePTFE barriers.

Notes: A recently described method for studying occlusal forces in prosthetically restored dentitions (Lundgren & Laurell, 1984) was applied in a standardized programme to elucidate the occlusal force pattern and the functional capability of a dentition during chewing and biting. The method is based on the use of strain gauge transducers mounted into preformed matrices evenly distributed over the tooth-arch. The programme was tested in a subject prosthetically restored with a fixed bridge of crossarch design in the upper jaw, and with unsplinted teeth in the lower jaw. It involved chewing of (a) peanuts, (b) roast beef with potato salad, biting with maximal strength in habitual occlusion and biting over one limited contact area at a time.The magnitude of the occlusal forces developed during chewing and swallowing was well below all biting forces.The magnitude of the total force acting over the entire dentition when biting at maximal strength in habitual occlusion did not seem to be limited by reactions from the teeth or the periodontal tissues but, seemingly, by the capability of the jaw-closing muscles themselves. The magnitude of the local bite force over one limited contact area at a time was much smaller than that which the jaw-closing muscles were able to develop. This indicated that feedback mechanisms in the periodontal tissues and/or the temporo-mandibular joints were limiting factors for these forces.The programme will be applied to studies of dentitions supplied with prosthetic constructions of various design and with different distribution of periodontal support.

Notes: The present paper describes a method developed to study occlusal forces in prosthetically restored dentitions. Using this method the magnitude, duration and frequency of the forces can be measured in various parts of the dentition simultaneously. The measurements are based on the use of strain gauge transducers of such dimensions that they can be mounted into artificial crowns, bridge-pontics or removable dentures, without interfering with the occlusion. The output signal of each transducer is linear for forces up to 300 N which corresponds to an amplitude (elastic deformation) of 20 μm.At least four transducers are used distributed over the tooth-arch to create bilateral and simultaneous contacts. They are mounted in a supraoccluding position of 20 μm in relation to non-transducer areas. This means that on jaw closure each transducer registers all the force transmitted to that part of the prosthetic construction represented by the transducer, provided there is no force leakage to non-transducer areas. The sum of these local forces constitutes the total force acting on the entire dentition at any given moment.

Notes: Background: Radiographic measurements are often used as a substitute for direct clinical measurements requiring re-entry surgery for follow-up outcome studies.〈section xml:id="abs1-2"〉〈title type="main"〉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〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:03036979:JCPE270305:les" location="les.gif"/〉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.

Notes: Abstract The aim of this study was to compare changes in periodontal status of a Swedish population over a 10-year period expressed as frequency distributions of individuals according to severity of periodontal disease experience. The study involved 600 randomly selected individuals evenly distributed into age groups 20, 30, 40, 50, 60 and 70 years, examined in 1973 and another randomly selected group of 597 individuals similarly age distributed and examined in 1983. Based on clinical data and full mouth intraoral radiographs all individuals were classified into 5 groups according to severity of periodontal disease experience, In 1983, 23% of the individuals were classified as having healthy periodontal tissues, group 1, compared to 8% in 1973. The changes were most pronounced in the age groups 20 and 30 years, among whom 58% and 35%, respectively, were registered as having healthy periodontal in 1983. The prevalence of individuals with gingivitis without signs of lowered periodontal bone level, group 2, was 22% in 1983 compared to 41% in 1973. In all, 49% of the dentate population in 1973 and 45% in 1983 showed no marginal alveolar bone loss. Moderate peridontal bone loss, group 3, was found in 41% of the population in 1983 compared to 47% in 1973. Among 30-. 40-, and 50-year-olds, there were more, and among 60- and 70-year-olds, fewer individuals in this group in 1983 compared to 1973. 96% of the dentate population were classified as belonging to groups 1, 2 or 3 in 1973 compared to 86% in 1983. Individuals with severe periodontal bone loss, group 4, were few in 1973 and not found before the age of 50, In 1983, the prevalence of individuals belonging to group 4 had increased and amounted to 1% of the 20-year-olds, 9% of the 50-year-olds, 25% of 60-year-olds and 38% of 70-year-olds. On the average, 11% of the dentate population were found in group 4 in 1983 compared to 2% in 1973. The prevalence of individuals belonging to group 5, i.e., alveolar bone loss around the majority of the teeth exceeding V, of the normal bone height and the presence of angular bony defects and/or furcation defects, was 1% in 1973 and 2% in 1983. There were no individuals younger than 40 years in this group. Based on gingivitis and probing pocket scores, 33% of the individuals classified to groups 3 and 4 were considered periodontally healthy although with reduced periodontal support. In periodontal disease severity group 5, no individual was considered periodontally healthy.