Raul G. Caffesse

Evaluation of a new bioresorbable barrier to facilitate guided bone regeneration around exposed implant threads. An experimental study in the monkey.

The aim of this study was to evaluate the effectiveness of a new bioresorbable barrier alone or in combination with BioOss for guided bone regeneration around dental implants with exposed implant threads. Five adult Macaca fascicularis monkeys were used in this investigation. After extraction of all premolars and first molars, two endosteal oral implants were installed in each quadrant and the bony defects were randomly treated with either: 1) placement of the new bioresorbable device alone (group 1); 2) placement of the new bioresorbable barrier in combination with BioOss (group 2); 3) placement of an ePTFE barrier in combination with BioOss (group 3); or (4) control (group 4). After a period of six months the animals were killed and the histological processing was performed. There was a significant difference in the amount of new bone regeneration around the implants between the four groups (i.e. groups 1, 2, 3 and 4) (P=0.0122). There was no difference, however, between group 2 and group 3. It can be concluded that the new bioresorbable barrier in combination with BioOss appears to obtain the same results in this type of bony defects as the grafting material in combination with an ePTFE barrier.

Clinical effects of chlorhexidine mouthwashes on patients undergoing orthodontic treatment

This study compared the short-term clinical effect of 0.12% chlorhexidine gluconate and placebo mouthrinses in 30 adolescents (ages 11 to 15) undergoing orthodontic treatment. Subjects were randomized into experimental (CHX) and control (C) groups. Baseline values were recorded 10 days after prophylaxis and included Plaque index (PI), Gingival index (GI), Rentention Index (RI), Discoloration index (DI), and probing depths (PD). Both groups (CHX and C) received soft toothbrushes with instructions to brush twice daily, as well as the CHX and placebo mouthrinses, respectively, with oral and written instructions for rinsing twice daily with 15 ml for 30 seconds. Reevaluations were performed 1, 2, and 3 months after baseline, except for the DI and PD, which were only assessed at 3 months. The Students t test and the paired t test were used to analyze the data at the P < 0.05 level of significance. No differences between groups were seen at baseline for any of the parameters. At 30 days, there was a significant difference for the RI between CHX (0.15 +/- 0.16; mean +/- SD) and C (0.05 +/- 0.06) at the mesial buccal, and for CHX (0.07 +/- 0.10) and C (0.02 +/- 0.05) at the midbuccal. The 60-day evaluation showed similar results. At 90 days, lower PI were observed in the CHX group at the distal buccal (0.38 +/- 0.19), midbuccal (0.22 +/- 0.17), and mesial buccal (0.47 +/- 0.22) sites as compared with the C group (0.97 +/- 0.38, 0.83 +/- 0.40, and 0.95 +/- 0.43, respectively). A similar trend was noted with the GI, as the lower values were related to the CHX group. The changes of the PI and GI, at 30, 60, and 90 days, as analyzed by the paired t test, were statistically significant in the case of the experimental group, as the changes in the means were a reflection of significantly lower scores observed in the experimental group. After 3 months, the DI showed higher scores in the experimental group as compared with the control, but they were not statistically significant. Deeper PD were detected in the C group at 90 days, and they were statistically significant, except for the midlingual site. The RI did not show significant differences at 90 days, but higher values were recorded in the CHX group. The data indicate that the use of the CHX, in addition to regular oral hygiene habits, was effective in reducing plaque and gingivitis in adolescents undergoing orthodontic treatment.

Relationship between diabetes and periodontal infection

Periodontal disease is a high prevalent disease. In the United States 47.2% of adults ≥ 30 years old have been diagnosed with some type of periodontitis. Longitudinal studies have demonstrated a two-way relationship between diabetes and periodontitis, with more severe periodontal tissue destruction in diabetic patients and poorer glycemic control in diabetic subjects with periodontal disease. Periodontal treatment can be successful in diabetic patients. Short term effects of periodontal treatment are similar in diabetic patients and healthy population but, more recurrence of periodontal disease can be expected in no well controlled diabetic individuals. However, effects of periodontitis and its treatment on diabetes metabolic control are not clearly defined and results of the studies remain controversial.

Evaluation of Guided Bone Regeneration and/or Bone Grafts in the Treatment of Ligature-induced Peri-implantitis Defects: A Morphometric Study in Dogs

The goal of this study was to evaluate, morphometrically, hard-tissue healing following the treatment of ligature-induced peri-implantitis defects in dogs and guided bone regeneration and/or bone grafts. Five dogs were used, and the mandibular premolars were removed. Three months later, two titanium implants were installed on each side of the mandible, and after another 3 months, abutment connection was performed. Following abutment connection, experimental periimplantitis was induced by placing cotton ligatures in a submarginal position. Ligatures and abutments were removed after 1 month and the bony defects were randomly assigned to one of the following treatments: debridement (DE), debridement plus guided bone regeneration (GBR), debridement plus mineralized bone graft (BG), and debridement plus guided bone regeneration associated with mineralized bone graft (GBR/BG). The dogs were euthanatized after 5 months. Morphometric analysis did not reveal significant differences among the treatments neither with respect to the percentage of bone to implant contact (p = 0.996) nor to the bone area (p = 0.946) within the limits of the threads of the implant. Within the limits of this investigation, there is insufficient evidence to indicate that any of the treatments presented an improved response in dealing with bony defects resulting from peri-implantitis.

Connective Tissue Response to Periodontal Dressings

The effects of three periodontal dressings (Coe-Pak, PPC, Perio Putty) upon subcutaneous tissues in 26 Sprague-Dawley rats were investigated. The three dressings, and a control (Teflon), were placed into polyethylene tubes. Two tubes per animal were implanted on either side of the dorsal midline area. After 14 days the specimens were retrieved and prepared for histological examination. Three methods of scoring were utilized for evaluation. First, a system evaluating the overall number of inflammatory cells, connective tissue capsule thickness, and the vascular changes produced; second, an inflammatory cell count, the Inflammatory Index (I.I.), computing the inflammatory cells in a particular field of view for each material; and third, a Reaction Spread Index (R.S.I.) comparing the distance of the spread of the inflammatory reaction into the connective tissues. Statistical analysis of the data was carried out utilizing the Chi-square test and analysis of variance. While the three scoring systems utilized did result in some comparative variation in reactions, the overall order of decreasing severity was always PPC, Coe-Pak, Perio Putty, and Teflon.

Characterization of Immunocompetent Cells in the Diseased Canine Periodontium

The beagle dog with naturally occurring periodontal disease is one of the most widely used animal models in periodontal research for histological studies on disease pathogenesis and on the effect of potential therapeutic regimens. However, previous studies were restricted to morphological assessment of immunocompetent cells because of the lack of available cell-specific markers. In this study we systematically characterized the specificity and immunoreactivity of a panel of anti-human antibodies for identification (ABC method) of immunocompetent cells in formalin-fixed, EDTA-decalcified, paraffin-embedded inflamed periodontal tissues obtained from six beagle dogs. Canine lymph nodes and a panel of different human tissues served as positive controls. Polyclonal anti-CD3 immunolabeled canine T-lymphocytes specifically. Anti-CD79 α (clone HM57) reacted with B-lymphocytes and plasma cells, and CD79 α (clone JCP117) showed no staining in canine tissues. Neutrophils, monocytes, small macrophages, and keratinocytes reacted with an anti-myeloid/histiocyte antibody (clone MAC387). Anti-CD68 (clones PG-M1 and EBM11) immunolabeled large macrophages and plasma cells. Clone EBM11 also stained osteoclasts and cementoclasts. With the exception of JCB117, all antibodies revealed similarly favorable immunolabeling of canine and human immunocompetent cells. Long-term EDTA decalcification appeared to weaken immunostaining of plasma cells with HM57. MAC387 and CD68 can be used to distinguish macrophages in different differentiation stages in canine periodontal tissues.

Clinical and Radiographic Evaluation Periodontal Intrabony Defects Treated With Guided Tissue Regeneration. A Pilot Study

BACKGROUND The aim of this clinical and radiographic study was to evaluate the effect of guided tissue regeneration using a bioabsorbable barrier in the treatment of intrabony defects in humans. METHODS Intrabony osseous defects (2 or 3 walls) around mandibular canines and premolars were treated in 10 systemically healthy patients with ages ranging from 35 to 56 years. Prior to the surgical phase, patients were enrolled in a strict maintenance program including oral hygiene instructions and scaling and root planing (presurgical PI and GI <10%). Patients were seen for professional prophylaxis during the duration of the study. Clinical measurements were performed with an electronic probe at baseline and at reentry 8 months following surgical therapy. Measurements included clinical attachment levels (CAL), gingival margin levels (GML), probing depths (PD), bone defect levels (BDL), and alveolar crest level (ACL). A split mouth design was used. Quadrants were randomly assigned for treatment by GTR (experimental) or open flap debridement alone control). Standardized radiographs were taken at baseline and at reentry. Digital images were analyzed by subtraction to assess changes in area (A) and optical density (OD). Data were evaluated using paired t test. RESULTS Statistically significant differences were found in both groups when comparing baseline and post-treatment values for CAL, GML, PD, and BDL (P <0.01). Greater reductions in BDL and gain in A and OD were observed in the GTR group when compared to control (P <0.01). Both therapies were effective in improving the clinical parameters assessed. CONCLUSION Clinical and radiographic findings from this study demonstrated more bone fill in sites treated with GTR. J Periodontol 2002;73:353-359.

17β-Estradiol Promotes Cementoblast Proliferation and Cementum Formation in Experimental Periodontitis

BACKGROUND Periodontitis is a chronic inflammatory condition that leads to the destruction of the tooth-supporting tissues. Its treatment includes the arrest of the inflammatory process and, in some circumstances, the restoration of the lost anatomy and function, including the formation of new cementum, periodontal ligament (PDL), and bone. With this goal, we investigated the effects of low concentrations of 17beta-estradiol on human cementoblast proliferation and its possible regenerative potential in vivo. METHODS Human cementum-derived cells obtained from a healthy human premolar were isolated and characterized by immunocytochemistry. Cell proliferation assays were performed to test the effects of 100 nM 17beta-estradiol and enamel matrix derivative (EMD). Three-wall intrabony periodontal defects were created in beagle dogs. After 1 month of plaque accumulation, 0.225 mg 17beta-estradiol impregnated in a collagen sponge was applied to randomly selected defects (test group), whereas a collagen sponge impregnated in a culture medium was applied to the control group. After 3 months, specimens were obtained, and tissue regeneration was assessed by histometric analysis. RESULTS Cells spreading out from human tooth-layer explants were able to form cell colonies, produce a mineral matrix, and express osteocalcin, indicating they were cementoblast-like cells. In contrast, PDL fibroblasts did not express osteocalcin. 17beta-estradiol, but not EMD, increased the rate of human cementoblast cell proliferation in vitro by 2.5-fold. Histometric results from the treated periodontal defects revealed that 17beta-estradiol promoted the formation of 2.94 mm of new cementum, (45% of the defects) compared to 1.54 mm of new cementum in the control group (28% of the defects). Furthermore, the test group showed an inhibition of epithelial downgrowth and a gain of new connective tissue attachment. CONCLUSION 17beta-estradiol promoted human cementoblast cell proliferation in vitro and periodontal regeneration in an experimental periodontitis model.

Efect of periodontal disease and non surgical periodontal treatment on C-reactive protein. Evaluation of type 1 diabetic patients.

Objectives: The purpose of this study was to analyze how anti-infectious periodontal treatment affects C reactive protein (CRP) values in patients with type 1 diabetes, and correlate baseline CRP levels with periodontal disease severity. Study Design: A cohort of fifty three subjects with type 1 diabetes and moderate to severe periodontitis were recruited. Periodontal parameters were measured, and blood samples were obtained to evaluate high-sensitivity C-reactive protein (hs-CRP). Group 1 was treated with scaling, root planning, and systemic administration of doxycycline. Group 2 received only scaling and root planning. Results: Hs-CRP was reduced after periodontal treatment in group 1 (-0.22 mg/l) and 2 (-0.21 mg/l ) but this reduction was not statistically significant, even in the patients with the best response to periodontal treatment. However, significant correlation appeared between hs-CRP and mean probing pocket depth (PPD) (p=0, 01) and mean clinical attachment level (CAL) (p=0,03). Conclusions: Non-surgical periodontal treatment couldn’t reduce hs-CRP values, however, it was found an association between advanced periodontitis and elevated blood hs-CRP levels in patients with type 1 diabetes. It can be speculated that periodontal disease increases production of pro-inflammatory mediators in patients with type 1 diabetes, but other producing sources of these pro-inflammatory substances may exist. Key words:Periodontal disease, periodontitis, diabetes mellitus type 1, periodontal therapy, C reactive protein.

Periodontium response to a root canal condensing device (Endotec)

Two Macaca (fascicularis) monkeys were used to study the effect of two warm endodontic condensation techniques (Endotec and vertical condensation method) on periodontal tissues. The specimens were histologically evaluated at 3 and 32 days after the endodontic treatments were completed. In this study the periodontium was divided into coronal, middle, and apical thirds. Results indicated that there was no heat-related damage to periodontal tissues from either of the two methods employed. However, some Endotec specimens generated small, reactive inflammatory infiltrates that were restricted to the root canal opening or adjacent periodontal membrane. Similarly, some vertical condensation specimens developed periapical inflammatory processes as well, but they were more extensive and comprised the alveolar bone and marrow spaces.