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PubMed1983

Insulin treatment reverses the postreceptor defect in adipocyte 3-O-methylglucose transport in type II diabetes mellitus.

The insulin resistance of type II diabetes mellitus is due to both receptor and postreceptor defects of in vivo insulin action, with the postreceptor defect being the predominant abnormality. Diminished glucose transport has been found in adipocytes from patients with type II diabetes, suggesting that decreased cellular glucose transport activity may be responsible in part for the in vivo postreceptor defect observed in these patients. Recent studies have shown that the in vivo postreceptor defect initially present in patients with Type II diabetes is significantly reversed by insulin therapy. For these reasons, we speculated that the defect in adipocyte glucose transport might also be corrected with exogenous insulin therapy. Therefore, we measured adipocyte 3-O-methylglucose transport in cells from five type II diabetic subjects before and after a 2-week period of intensive insulin treatment. Glycemic control was significantly improved by this regimen. The mean (+/- SE) fasting serum glucose level fell from 292 +/- 24 to 135 +/- 29 mg/100 ml (P less than 0.005), and the mean integrated glucose area under a 7-h meal tolerance test curve decreased from 171,212 +/- 20,403 to 72,408 +/- 9,292 mg/min . dl. The mean 3-O-methylglucose transport activity increased after treatment at all insulin concentrations studied, including basal (before, 0.18 +/- 0.05; after, 0.45 +/- 0.09 pmol/2 X 10(5) cells . 10 sec; P less than 0.005) and maximally effective (25 ng/ml) insulin concentrations (before, 0.50 +/- 0.14; after, 1.32 +/- 0.30 pmol/2 X 10(5) cells . 10 sec; P less than 0.025), although the mean maximal glucose transport activity was still 25% decreased compared to normal values, indicating that a residual in vitro postreceptor defect remained. These results corresponded well with the degree of reversal (75%) of the in vivo postreceptor defect, as assessed by the euglycemic glucose clamp technique. These studies demonstrated that the decrease in adipocyte glucose transport activity in type II diabetes is practically reversible by intensive insulin therapy. This closely corresponds to the reversal by insulin therapy of the postreceptor defect expressed in vivo and provides further evidence that a cellular cause of the postreceptor defect in type II diabetes is a decrease in glucose transport system activity in the major insulin target tissues.

3-O-Methylglucose↗
PubMed1999

Visual field defects after temporal lobe resection: a prospective quantitative analysis.

OBJECTIVE: To evaluate and quantify prospectively visual field changes in patients undergoing temporal lobe resections for intractable epilepsy. BACKGROUND: Visual field abnormalities occur after temporal lobe resections for epilepsy; however, we have not encountered published reports using automated static visual field analysis. METHODS: Humphrey visual fields (program 30-2) were obtained before and after partial temporal lobe resection in 32 consecutive patients with intractable epilepsy. A quantitative point-by-point analysis was made in the affected superior quadrant, and the defects were averaged for the whole patient group. RESULTS: Thirty-one patients developed a visual field defect, but none was aware of the defect. The points nearest fixation were relatively spared. The defects were greatest in the sector closest to the vertical meridian in the eye ipsilateral to the resection. The ipsilateral and contralateral mean field defects also differed in both topography and depth. A significant correlation was found between the extent of lateral temporal lobe resection and the degree of the defect in the contralateral eye. CONCLUSIONS: There are differences in the shape and depth of the ipsilateral and the contralateral field defects not previously reported. These findings demonstrate that certain fibers from the ipsilateral eye travel more anteriorly and laterally in Meyer's loop, and support the hypothesis that visual field defects due to anterior retrogeniculate lesions are relatively incongruous because of anatomic differences in the afferent pathways. Automated perimetry is a sensitive method of evaluating and quantifying visual field defects.

Adolescent↗
PubMed1993

Reconstruction of skull defects in children and adolescents by the use of fixed cranial bone grafts: long-term results.

This article presents the long-term results of skull defect reconstruction in a series of 27 children studied between 1986 and 1990 (mean age, 8.4 yr; range, 1-17 yr). Causes of their defects were encephalocele (six patients), trauma (seven patients), tumor (eight patients), fibrous dysplasia (two patients), postsynostectomy defects (two patients), osteomyelitis (one patient), and Reye's syndrome with bone flap loss (one patient). All patients underwent clinical and computed tomographic scan documentation of their skull defects before and immediately after surgery and at least 1 year later. The average preoperative defect surface area measured 33 cm2 (range, 2.5-114 cm2). Skull defects were reconstructed in all patients with fixed autogenous cranial bone grafts. In the initial five patients, the grafts were fixed with interosseous wires, and in the remainder, they were fixed with a combination of miniplates and microplates and screws. Follow-up ranged from 12 to 66 months (mean, 31.4 mo). Complications were minimal, with no infection, plate or graft exposure, or intracranial injuries. In 24 of 27 patients, clinical examination and computed tomographic scans showed no evidence of skull defect or appreciable irregularity of donor or recipient sites. Two patients had documented small regions of graft resorption. One skull had palpable contour irregularities but without a bony defect. All patients have resumed routine activities and sports without special head protection. Repair of skull defects in children with fixed autogenous cranial grafts is a reliable method of reconstruction with minimal morbidity. Although we prefer miniplates and microplates and screws for fixation, the grafts fixed in place with interosseous wires did equally well.

Adolescent↗
PubMed1989

Relationship of thallium-201 defect and left ventricular function after dipyridamole infusion.

Tl-201 imaging and first-pass radionuclide ventriculography (RNV) by 4 min infusion of 0.56 mg/kg dipyridamole were performed on 22 patients with coronary artery disease in order to know the relationship of myocardial perfusion and left ventricular function after dipyridamole-infusion, and thereby to define whether Tl-201 defect with dipyridamole could imply myocardial ischemia. Initial and delayed Tl-201 images were divided into anterior, apical, and infero-posterior segments, and segmental perfusion defects were categorized as reversible, fixed and no defect. RNV on the 30-degree right anterior oblique view was also divided into anterior, apical, and infero-posterior wall to be evaluated for regional wall motion by a 5 point score before and after dipyridamole. Changes in left ventricular ejection fraction (LVEF) with dipyridamole were also calculated. Normal responses of regional wall motion and LVEF to dipyridamole were established from the data of 14 normal subjects. Reversible defects were closely associated (69%) with an abnormal response of regional wall motion (score decrease of 1 or more after dipyridamole). Both fixed defects and no defects showed little association with abnormal response of regional wall motion. Moreover, 77% of the patients having reversible-defect segment showed an abnormal response of LVEF (reduction of 3% or more following dipyridamole). However, patients without reversible defect did not show an abnormal response to dipyridamole. These results suggest that dipyridamole-induced Tl-201 defects represent a myocardial ischemia which causes a reduction of ventricular function.

Adult↗
PubMed1998

Repair of ulnar segmental defect by recombinant human bone morphogenetic protein-2 in dogs.

The efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with poly D, L lactic-co-glycolic acid (PLGA)/gelatin sponge complex (PGS) as a carrier on the repair of segmental long-bone defects was evaluated using an ulnar model in dogs. The defect was 2 cm in length and was fixed with bone plating. After implantation of PGS with or without rhBMP-2, the repair process of the defect was evaluated by serial radiography until 16 postoperative weeks. All defects treated with 160 micrograms or 640 micrograms of rhBMP-2/PGS revealed bone union radiographically by 12 postoperative weeks, whereas all defects treated with PGS alone revealed no radiographic evidence of healing throughout the experimental period. In defects treated with 40 micrograms of rhBMP-2/PGS, new bone appeared partially at the defects but did not accomplish union. Bone mineral contents at the defect sites after harvest at 16 weeks postoperatively were significantly (p < 0.05) higher in those treated with 160 micrograms or 640 micrograms of rhBMP-2 than in those treated with 40 micrograms of rhBMP-2 or PGS alone. Histologically, defects radiographically diagnosed as having achieved union showed the appearance of cortical bone and bone marrow cells. These findings suggest the use of rhBMP-2/PGS as a potential bone graft substitute in reconstructive surgery in dogs.

Animals↗
PubMed2005

[Location and frequency of visual field defects as measured by SITA (Swedish Interactive Threshold Algorithm) strategy in primary open angle glaucoma].

PURPOSE: To evaluate the frequency, location and pattern of visual field defects as measured by SITA strategy in primary open angle glaucoma (POAG). METHODS: Six thousand and two-hundred charts were reviewed. One hundred and fifty two patients who fulfilled the inclusion criteria were included. They were stratified according to severity into early, moderate and severe. The following visual field defects were defined: nasal step, paracentral scotomata, arcuate defect, Seidel scotomata, temporal defect, general reduction of sensitivity, annular scotomata and central island. Each examination was divided into sectors corresponding to optic disc regions. Student's t test was used to compare differences in frequency. RESULTS: In the early glaucoma group, the nasal superior step was the most frequent visual field defect, followed by paracentral scotoma and inferior nasal step. General reduction of sensitivity was noted in 7.8%. Defects were more common in the superior hemifield (p<0.05). CONCLUSION: The superior nasal step and paracentral scotoma were the most commun visual field defects in early primary open angle glaucoma as evaluated by SITA strategy, and the superior hemifield comprises most of the defects. General reduction of sensitivity was an early and rare visual field defect.

Adult↗
PubMedDate not supplied

[Assessment of bovine biomaterials containing bone morphogenetic proteins bound to absorbable hydroxyapatite in rabbit segmental bone defects].

PURPOSE: To evaluate the osteo-regenerative capacity of two proprietary bone grafting materials, using a segmental defect model in both radial diaphyses of rabbits. METHODS: The right defect was filled with pooled bone morphogenetic proteins (pBMPs) bound to absorbable ultrathin powdered hydroxyapatite (HA) mixed with inorganic and demineralized bone matrix and bone-derived collagen, derived from bovine bone (Group A). The left defect was filled with bovine demineralized bone matrix and pBMPs bound to absorbable ultrathin powdered HA (Group B). In both groups, an absorbable membrane of demineralized bovine cortical was used to retain the biomaterials in the bone defects, and to guide the tissue regeneration. The rabbits were euthanized 30, 90 and 150 days after surgery. Radiographic, tomographic and histologic evaluations were carried out on all specimens. RESULTS: At 30 days, the demineralized cortical bone cover was totally resorbed in both groups. HA was totally resorbed from Group A defects, whereas HA persisted in Group B defects. A prominent foreign body reaction was evident with both products, more pronounced in sections from Group B. At 90 days, the defects in Group B exhibited more new bone than Group A. However, at 150 days after surgery, neither treatment had stimulated complete repair of the defect. CONCLUSION: The partial bone healing of the segmental defect occurred with low or none performance of the biomaterials tested.

Animals↗
PubMed1995

Guided bone regeneration in calvarial bone defects using polytetrafluoroethylene membranes.

Guided bone regeneration is defined as controlled stimulation of new bone formation in a bony defect, either by osteogenesis, osteoinduction, or osteoconduction, re-establishing both structural and functional characteristics. Bony defects may be found as a result of congenital anomalies, trauma, neoplasms, or infectious conditions. Such conditions are often associated with severe functional and esthetic problems. Corrective treatment is often complicated by limitations in tissue adaptations. The aim of the investigation was to compare histologically the amount of bone formed in an experimentally created parietal bone defect protected with one or two polytetrafluoroethylene membranes with a contralateral control defect. A bony defect was created bilaterally in the parietal bone lateral to the sagittal suture in 29 6-month-old male Wistar rats. The animals were divided into two groups: (1) In the double membrane group (n = 9), the left experimental bone defect was protected by an outer polytetrafluoroethylene membrane under the periosteum and parietal muscles and an inner membrane between the dura mater and the parietal bone. (2) In the single membrane group (n = 20), only the outer membrane was placed. The right defect was not covered with any membrane and served as control. The animals were killed after 30 days. None of the control defects demonstrated complete or partial bone regeneration. In the single membrane group, the experimental site did not regenerate in 15 animals, partially in four, and completely in one. In the double membrane group, six of the experimental defects had complete closure with bone, two had partial closure, and one no closure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Doxycycline-tricalcium phosphate composite graft facilitates osseous healing in advanced periodontal furcation defects.

The purpose of this study was to compare the effectiveness of a tricalcium phosphate, plaster of paris, and doxycycline composite graft to surgical debridement alone in the treatment of Class II and Class III furcation defects. Fifteen patients with adult periodontitis and at least two mandibular molars with Class II or III furcation defects were selected. A total of 40 sites were treated: 26 were Class II defects and 14 were Class III. Following initial therapy one site was randomly selected to receive the composite graft while the remaining site served as the surgically debrided control. Osseous healing was evaluated by direct measurements from an acrylic stent at the time of graft surgery and at the 6-month reentry. Following surgery each patient was placed on doxycycline 100mg/day for 10 days. The absence of clinical inflammation and infection during the healing process provided additional substantiation of the biocompatibility of the grafting materials. Results after 6 months indicated that sites treated with the composite graft had improved defect fill, defect resolution, probing depths, and clinical attachment levels when compared to the surgically debrided controls. Defect fill was 3.7 times greater in grafted sites and these sites were 4.0 times more likely to have 50% or greater defect fill. The effect of grafting was more pronounced in Class III defects where horizontal defect fill and gain of clinical attachment was achieved only in grafted sites. The plaster of paris functioned well as a binder, preventing particle scatter and facilitating graft retention. Additionally the plaster served as a vehicle to carry and retain the doxycycline at the treated site. These short-term results point to the potential of a composite graft containing tricalcium phosphate, plaster of paris, and doxycycline in promoting healing of furcation lesions.

Adult↗
PubMed1993

A comparison of polylactic acid granules and decalcified freeze-dried bone allograft in human periodontal osseous defects.

The purpose of this study was to compare the effectiveness of polylactic acid (PLA) granules as an alloplastic grafting material to that of decalcified freeze-dried bone allograft (DFDBA) and a flap procedure for debridement without graft (FPD) when treating periodontal intrabony defects. Ten patients presenting with advanced adult periodontitis, including at least 3 similar periodontal osseous defects (2- and 3-walled), comprised the study group. After completion of a hygienic phase of treatment, measurements were made with calibrated periodontal probes and stents to determine soft tissue recession, probing pocket depths, and probing attachment levels. Each defect was surgically exposed and hard tissue measurements were obtained. Defects were treated with one of the 3 methods above chosen randomly prior to the surgical appointment. Six months postsurgery, soft tissue measurements were repeated and all sites were surgically reentered to obtain hard tissue measurements. All surgical sites healed without clinical complication. The initial pocket depths and initial depth of osseous defects were compared between the groups using ANOVA and no significant differences were found. A mean osseous defect fill of 0.4 mm (11.2%) occurred with the flap procedure for debridement, 3.0 mm (65%) with DFDBA, and 0.1 mm (2.2%) with PLA. Mean crestal bone loss was 1.30 mm for FPD, 0.60 mm for DFDBA, and 1.55 mm for PLA. No statistically significant differences were found in soft tissue recession between groups or in the osseous defect measurement between PLA and FPD. A statistically significant improvement (P < 0.001) was found in the fill of the osseous defects when using DFDBA compared to the initial defect depth and to the other 2 groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Cryopreserved cancellous bone allograft in periodontal intraosseous defects.

The purpose of this study was to evaluate the potential of cryopreserved cancellous bone allograft (CCBA) in the treatment of intraosseous periodontal defects compared to surgical debridement alone (DEBR). Cancellous bone was procured from femur heads that had been extracted for hip prosthesis procedures and cryopreserved in liquid nitrogen (-196 degrees C) in a tissue bank. Ten patients without systemic disorders and advanced periodontal disease (at least 2 intraosseous defects) participated in this investigation. Measurements from the cemento-enamel junction were made after initial therapy for clinical attachment level; also gingival recession, probing pocket depth, plaque index, and gingival index and, at the time of surgery, alveolar crest height and osseous defect depth were measured. All measurements were repeated at 1 year-reentry. Sixteen defects were debrided and grafted (test sites) and 13 defects were debrided only (control sites). Soft tissue measurements showed no statistical differences between the 2 groups. Defect fill was significantly greater with CCBA (1.75 mm) than with DEBR (0.56 mm). Defect depth reduction was 2.06 mm for CCBA and 0.78 mm for DEBR. These values correspond to a percent-defect resolution of 60% for CCBA and 29% for DEBR. Hard tissue measurements showed significant differences between the 2 groups. CCBA seems to be effective in the short-term treatment of intraosseous periodontal defects.

Adult↗
PubMed1994

Clinical evaluation of coralline calcium carbonate as a bone replacement graft material in human periodontal osseous defects.

A resorbable coralline calcium carbonate graft material (CalCarb) was compared to open flap debridement (DEBR) in human periodontal osseous defects. Following appropriate initial preparation procedures, flap surgery with defect and root debridement was performed in 20 patients. Alternating defects in each segment of surgery were treated with each procedure. Appropriate periodontal maintenance schedules were followed, and at 6 to 12 months a re-entry flap surgery was performed for documentation and finalization of treatment. Forty defects which received CalCarb grafts demonstrated significantly better mean defect fill of 2.3 mm (67.7%) versus a mean defect fill of 0.7 mm (25.9%) (P < 0.01) for 39 defects treated with DEBR. Other hard tissue findings showed similar clinically superior results with the use of CalCarb. Relative defect fill results showed 88% positive (50% to 100% defect fill) responses with CalCarb and only 13% positive responses with DEBR. There were 7 times more failures (minimal response) with DEBR than with CalCarb. Soft tissue findings showed no significant differences between treatments. These results are similar to those with other synthetic and natural bone replacement graft materials. However, the ease of handling of the CalCarb material, its resorbability, and its potential for improved bone regeneration may be of clinical advantage.

Adult↗
PubMed1995

Evaluation of a collagen membrane with and without bone grafts in treating periodontal intrabony defects.

The aim of this study was to compare the clinical regenerative capacity of collagen membrane with and without demineralized freeze-dried bone allografts (DFDBA) in treating periodontal intrabony defects. Ten systemically healthy patients with similar bilateral periodontal defects were scheduled for surgery. Each patient had at least > or = 6 mm clinical probing depth and loss of attachment at selected sites. Baseline measurements included gingival index (GI), plaque index (PI), gingival recession (GR), clinical attachment level (CAL), probing depth (PD), and mobility. At the time of surgery, the defects were randomly assigned to either test (collagen membrane plus DFDBA) or control group (collagen membrane only). Stent to base of the defects, stent to crest bone, crest of bone to base of the defect, and width of the defects were recorded at the time of surgery and reentry. Eight patients returned after 6 months for reentry surgery. Statistical analysis with a paired t test was used to evaluate the treatment effect and comparison between test and control groups. In addition, a McNemar test was used to analyze the significance of GI, PI, and mobility at different times. The result of this study indicated that both the collagen plus DFDBA and the collagen alone treatment groups had a significant decrease of PD (3.4 +/- 0.4 and 3.2 +/- 0.4 mm), gain of CAL (2.3 +/- 0.5 and 2.0 +/- 0.4 mm), and defect fill (1.7 +/- 0.3 and 1.9 +/- 0.9 mm) (P < 0.05) when compared to the presurgery status. However, there was no significant difference in PD, AL, GR, defect fill, crestal bone resorption, GI, PI, or mobility between the test group and control group. No adverse tissue reaction, infection, or delayed wound healing was noted throughout the treatment in either group. This study suggests that the collagen membrane is well tolerated by the human tissues. Both treatments, either collagen membrane plus DFDBA or collagen membrane alone, promoted significant resolution of periodontal intrabony defects. The addition of a bone graft (DFDBA) with a collagen membrane appears to add no extra benefit to the collagen membrane treatment.

Adult↗
PubMed1997

Histological comparison of early wound healing following dense hydroxyapatite granule grafting and barrier placement in surgically-created bone defects neighboring implants.

The purpose of this study was to examine early wound healing following grafting of dense hydroxyapatite granules (HA granules) and barrier placement in surgically-created bone defects surrounding implants. Eight healthy adult dogs with an average weight of 15 kg were used in this study. Thirty-two bone defects measuring 4 mm x 4 mm were removed with a surgical bur to form continuous bucco-lingual bone defects and 32 implants (16 titanium [Ti]) and 16 hydroxyapatite-coated [HA]) were then placed into the defects. Four implant groups were created: 1) grafting HA; 2) covering with an expanded polytetrafluoroethylene (ePTFE) membrane; 3) grafting HA and covering with ePTFE membrane; and 4) control (no treatment). Animals were sacrificed 28 days after surgery. Histological sections revealed large amounts of newly-formed bone in all bone defects surrounding the implants treated with ePTFE membranes alone. Fibrous encapsulation of HA granules was observed in the defects of the HA granules grafting group. In the group with grafting of HA granules and covering with ePTFE membranes, small amounts of bone tissue were observed among HA granules, but most HA granules were surrounded with fibrous tissue. Bone defects were completely filled with connective tissue in the control group. There were no differences in the histological findings between Ti and HA-coated implants in all cases. Histomorphometric data disclosed that the presence of HA granules in the bone defects significantly arrested bone formation. Our study suggests that the grafting of dense HA into bone defects surrounding implants will result in fibrous healing during the early healing stage.

Alveolar Bone Loss↗
PubMed1998

Treatment of intrabony defects by different surgical procedures. A literature review.

This article reviews studies presented during the last 20 years on the surgical treatment of intrabony defects. Treatments include open flap debridement alone (OFD); OFD plus demineralized freeze-dried bone allograft (DFDBA), freeze-dried bone allografts (FDBA), or autogenous bone; and guided tissue regeneration (GTR). The review includes only studies that presented baseline and final data on probing depths, intrabony defect depths as measured during surgery, clinical attachment level (CAL) gain, and/or bone fill. Some reports were case studies and some controlled studies comparing different treatments. In order to assess what can be accomplished in terms of pocket reduction, clinical attachment level gain, and bone fill with the various treatment modalities, data from studies of each treatment category were pooled for meta-analysis in which the data from and power of each study were weighted according to the number of defects treated. In addition, where there were data for each individual defect treated, these were used for simple regression analysis evaluating the influence of intrabony defect depth on treatment outcome in terms of CAL gain and bone fill. This was done in an effort to assess some predictability of the outcome of the various treatments. OFD alone resulted in limited pocket reduction, CAL gain averaged 1.5 mm and bone fill 1.1 mm. Bone fill, but not CAL gain, correlated significantly to the depth of the defect (R=0.3; P < 0.001), but the regression coefficient was only 0.25. OFD plus bone graft resulted in limited pocket reduction. CAL gain and bone fill averaged 2.1 mm. Bone fill showed a somewhat stronger correlation to defect depth than following OFD alone (R=0.43; P < 0.001) with a regression coefficient of 0.37. GTR resulted in significant pocket reduction, CAL gain of 4.2 mm, and bone fill averaging 3.2 mm. CAL gain and bone fill correlated significantly (P < 0.001) to defect depth (R=0.52 and 0.53 respectively) with the largest regression coefficients (0.54 and 0.58 respectively) among the three treatment modalities. By comparing outcomes following the various treatments it became obvious that to benefit from GTR procedures, the intrabony defect has to be at least 4 mm deep.

Alveolar Process↗
PubMed2000

Treatment of multiple recession-type defects in patients with esthetic demands.

BACKGROUND: When multiple recession defects affecting adjacent teeth in esthetic areas of the mouth are present, patient-related considerations suggest the selection of surgical techniques that allow all gingival defects to be simultaneously corrected with the soft tissue close to the defects themselves. The aim of the present study was to evaluate, with respect to root coverage, the effectiveness of a new surgical approach to the coronally advanced flap procedure for the treatment of multiple recession defects in patients with esthetic demands. METHODS: Twenty-two young systemically and periodontally healthy subjects with at least 2 recession-type defects affecting adjacent teeth in esthetic areas of the mouth were enrolled in the study. All recessions were Miller Class I or II. In each patient, all present recessions were treated at the same time with a modification of the coronally advanced flap technique. The clinical re-evaluation was made 1 year after the surgery. RESULTS: A total of 73 recessions (mean recession depth 2.8 mm) were treated; mean number of gingival recessions in each subject was 3.4. At the 1-year examination, on average, 97% of the root surface was covered with soft tissue and 64 defects (88%) showed complete root coverage. Complete root coverage in all recessions was achieved in 16 out of 22 patients (73%), and no statistically significant relationship was found between the root coverage results and the number of recession defects treated in each patient. A statistically significant increase of keratinized tissue (0.6 mm) was observed after 1 year; this increase was inversely correlated (P <0.001) with the amount of presurgical keratinized tissue. The multiple regression model showed that the final result, in terms of root coverage, was significantly affected by the initial recession depth and by the amount of presurgical keratinized tissue. Greater reductions in recession depth were observed in the cases with worse initial conditions and with lesser amount of keratinized tissue apical to the recession defect. CONCLUSIONS: The results of the present study demonstrated that the proposed surgical technique was very effective for the treatment of multiple gingival recessions affecting teeth in esthetic areas of the mouth and that these successful root coverage results could be achieved irrespective to both the number of recessions simultaneously treated during the surgical intervention and the presence, before surgery, of a minimal amount of keratinized tissue apical to the defects.

Adolescent↗
PubMed2004

Bone apposition in surgical bony defects following orthodontic movement: a comparative histomorphometric study between root- and periodontal ligament-damaged and periodontally intact rat molars.

BACKGROUND: The influence of orthodontic tooth movement with diminished periodontal support is unclear. The aim of the present study was to evaluate bone healing in surgical defects following orthodontic tooth movement with and without periodontal ligament (PDL) and root surface damage. METHODS: The study comprised 33 adult male Wistar rats, divided into two groups: group 1 (n = 14) with bony defect and no root damage and group 2 (n = 19) with periodontal bony defect including root/PDL damage on the mesial root of the maxillary first molar. One week after a surgical defect was created, orthodontic protraction of the right maxillary first molar was initiated in both groups. After 2 weeks of protraction, retention of 1 week was established; at the end of this period block sections were made. Histomorphometric analysis through light microscopy of decalcified tissue was performed. Results were statistically analyzed using independent samples t test and analysis of variance (ANOVA) with repeated measures. RESULTS: Differences between groups in total area of bone defect and bone apposition were not statistically significant. Bone apposition calculated as percentage of the bone defect was significantly (t-test) greater (P = 0.002) in group 2 (46.21%) than in group 1 (24.95%). Within each group, area of bone apposition was significantly (ANOVA) greater in the distal than in the mesial quadrants of the bony defect (P = 0.006) and in the apical than the occlusal ones (P = 0.021). CONCLUSION: Following orthodontic tooth movement, periodontal bony defects showed enhanced bony healing compared with alveolar bone defects with no direct association with the periodontal attachment apparatus.

Alveolar Bone Loss↗
PubMed2006

Bioabsorbable membrane and bioactive glass in the treatment of intrabony defects in patients with generalized aggressive periodontitis: results of a 5-year clinical and radiological study.

BACKGROUND: The aim of this clinical and radiological prospective 5-year study was to compare the long-term effectiveness of a bioabsorbable membrane and a bioactive glass in the treatment of intrabony defects in patients with generalized aggressive periodontitis. METHODS: Sixteen patients (11 women and five men) with generalized aggressive periodontitis were enrolled in the study. The investigations were confined to 1- to 3-walled intrabony defects with a depth >/=4 mm and with preoperative probing depths (PDs) >/=7 mm. Teeth with furcation involvement were excluded. Twenty-two of the defects were treated with the membrane (RXT group) and 20 with the bioactive glass (PG group). Allocation to the two groups was randomized. The clinical parameters plaque index (PI), gingival index (GI), PD, bleeding on probing (BOP), gingival recession (GR), clinical attachment level (CAL), and tooth mobility were recorded before surgery and at 6 months and every year for 5 years after surgery. Intraoral radiographs were taken using a standardized paralleling technique at baseline and every year for 5 years. Statistical analysis was based on Kolmogorov-Smirnov and Wilcoxon signed-rank tests, analysis of covariance, and Spearman's bivariate correlation analysis. RESULTS: After 5 years, a reduction in PD of 3.6 +/- 0.8 mm (P = 0.016) and a gain in CAL of 3.0 +/- 2.0 mm (P = 0.01) were registered in the RXT group. There was a slight increase in GR by 0.6 +/- 1.4 mm (P = 0.334). In the PG group, a reduction in PD of 3.5 +/- 1.4 mm (P = 0.01) and a gain in CAL of 3.3 +/- 2.1 mm (P = 0.01) were recorded, whereas GR increased by 0.2 +/- 1.7 mm (P = 0.525). The 1-, 2-, 3-, and 4-year results did not differ significantly from the 5-year results. Radiographically, the defects (the point on the proximal surface of the defective tooth at which the projected alveolar crest intersected the root surface [xCA] to the most coronally located point at the proximal surface of the tooth on the defect side up to which the periodontal ligament space still displayed a uniform width [xBD]) were found to be filled by 47.5% +/- 38.3% (P = 0.001) in the RXT group and by 65.0% +/- 50.5% (P = 0.001) in the PG group. Crestal resorption (the most apical point of the enamel at the proximal surface of the tooth on the defect side [xCEJ] to the xCA) was 19.0% +/- 30.2% (P = 0.374) in the RXT group and 12.3% +/- 38.6% (P = 0.647) in the PG group. The xCEJ to the xBD was significantly more in the PG group (28.4 +/- 24.6 versus 7.3 +/- 21.8, P = 0.048). A good standard of oral hygiene and inflammation-free periodontal tissue in the postoperative phase improved the treatment outcome. No dependence of attachment gain was found on the tooth type, number of walls involved in the defects (r = 0.075; P = 0.319), or intraoperative depth (r = 0.114; P = 0.307). CONCLUSIONS: Highly significant improvements in the parameters PD and CAL were recorded after 5 years with both regenerative materials. Radiographically, the defects (the xCED to the xBD) were found to be filled significantly more in the bioactive glass group. A good standard of oral hygiene and inflammation-free periodontal tissue in the postoperative phase improved the treatment outcome.

Absorbable Implants↗