Pluronic polyol effects on human gingival fibroblast attachment and growth.

BACKGROUND: Enhanced speed of human gingival fibroblast (HGF) spreading and attachment, as affected by ionic bonding interactions, may facilitate cell orientation and subsequent collagen synthesis to promote early wound healing. The purpose of this study was to determine the in vitro effects of pluronic polyols, a family of widely used surfactants currently used as drug carriers for antibiotic, anti-inflammatory, and anti-neoplastic agents, on the attachment and growth of human gingival fibroblasts (HGF) to dentin and plastic surfaces using established tissue culture techniques. METHODS: Plastic culture wells containing Eagle's minimal essential media (EMEM) with 10% fetal calf serum and Pluronic F-68 or F-127 in concentrations from 1.2 x 10(-2) to 1.2 x 10(-10) M were incubated with HGF and run in replicates of ten. Attached cells were quantified by measuring the optical density of methylene blue-stained cells. Additional experiments were conducted using human dentin sections as a substrate and Pluronic F-68 or F-127 at a concentration of 1.2 x 10(-8) M. In these experiments, HGF were stained with acridine orange and quantified per unit area of dentin by fluorescence microscopy. RESULTS: Attachment and growth of HGF to both plastic and dentin were significantly increased over serum controls by very low concentrations of Pluronic F-68 and F-127 by 30 minutes, with attachment reaching a plateau at 2 hours. CONCLUSIONS: Pluronic polyols, a family of widely used surfactants, in very low dosages may be beneficial in early postsurgical wound healing by facilitating early attachment and enhancing the growth rate of human gingival fibroblasts.

Evaluation of titanium implants placed into simulated extraction sockets: a study in dogs.

The purpose of this study was to evaluate the effect of gap width on bone healing around implants placed into simulated extraction socket defects of varying widths in 10 mongrel dogs. All premolars were removed and the alveolar ridges were reduced to a width of 7 mm. Nine weeks later, a total of 80 implants, 10 mm long by 3.3 mm wide, were placed into osteotomy sites prepared to 3 different diameters in the coronal half, simulating extraction sockets. Three experimental sites, with gap sizes of 0.5 mm, 1.0 mm, and 1.4 mm, were created; the control sites had no gap. The depth of each defect was measured at the time of implant placement. All implants were stable at the time of placement. The dogs were euthanized 12 weeks after implant placement, and blocks containing the implants and adjacent bone were submitted for histologic evaluation. Clinically, all control and test sites healed, with complete bone fill in the defect. Percentages of bone-to-implant contact were measured histologically. As the gap widened, the amount of bone-to-implant contact decreased, and the point of the highest bone-to-implant contact shifted apically. These changes were statistically significant (P < .001). No statistically significant differences in bone-to-implant contact were found between the sites when the apical 4 mm of implants were compared. Within the limits of this study, the simulated extraction socket defects healed clinically, with complete bone fill, regardless of the initial gap size. However, the width of the gap at the time of implant placement had a significant impact on the histologic percentage and the height of bone-to-implant contact.

Suture materials and techniques.

Surgical improvements in periodontics have been achieved because of advances in basic science, animal and clinical research, and the insight of outstanding clinicians. Industry continues to develop new surgical materials, improving the quality of sutures and needles and in turn, supporting advances in all surgical specialties. The purpose of this article is to review sutures and suturing by focusing on both materials and methods as they relate to the present practices of surgical periodontics and dental implants.

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.

Regenerative treatment of periodontal defects utilizing a bioresorbable collagen membrane.

Barrier membranes composed of resorbable collagen have demonstrated potential for use in guided tissue regeneration (GTR) procedures for repair and regeneration of periodontal defects. This article reviews the rationale for use of a collagen membrane in GTR therapy and related clinical procedures. Characteristics of the material are outlined, and indications and contraindications for utilization are discussed. Two cases are presented to demonstrate details of these principles and techniques. The learning objective of this article is to familiarize the reader with a new absorbable collagen membrane and its application in the periodontal area.

Evaluation of an absorbable collagen membrane in treating Class II furcation defects.

Recent research has focused upon the utilization of an absorbable collagen membrane in guided tissue regeneration (GTR). Concern exists as to whether this type of membrane is beneficial in the treatment of periodontal defects. The purpose of this study was to evaluate the effect of a type I bovine collagen membrane on treatment of Class II furcation defects. Twelve systemically healthy patients (six male and six female, ages 32 to 68) were treated. Each had bilateral mandibular furcation defects with attachment loss > or = 6 mm. Prior to surgery all patients completed initial therapy including scaling and root planing. At the time of the surgery, teeth were randomly assigned to either a control (flap debridement alone) or test (flap debridement plus collagen membrane) group. Data were collected on the day of surgery, and 2, 4, and 6 months post-surgery and at the 12 month re-entry surgery. Clinical measurements included probing depth (PD), clinical attachment level (CAL), gingival recession (GR), stent to base of defect (SB), crestal bone to base of defect (CB), width of defect, and mobility. Statistical analysis was performed utilizing the paired t test. Both control and test groups demonstrated significant (P < 0.05) improvement at 12 months re-entry in PD, CAL, SB, and CB when compared to the presurgery status. While there is no significant difference in PD, CAL, GR, width of defect, and mobility between control and test groups, sites treated with the collagen membrane had significantly higher bone fill (SB and CB) at re-entry.(ABSTRACT TRUNCATED AT 250 WORDS)

An in vitro study of dentinal tubule occlusion by ferric oxalate.

This study examined ferric oxalate's ability to occlude dentinal tubules both in the presence of a smear layer and after its removal. Radicular dentinal chips were prepared with a smear layer created from a high speed carbide bur. The dentinal chips were then grouped as follows: 1) those with the smear layer remaining intact; 2) those sonicated for 7 minutes; 3) those treated with 10% tetracycline HCl; 4) those treated with 0.5M EDTA; 5) those treated with 20% citric acid; or 6) those treated with saturated citric acid. Six percent ferric oxalate was applied for 1 minute to the dentinal chips under blinded conditions. The chips were examined under SEM and the number of small and large crystals formed were counted. The results indicate that a decrease in the number of small crystals occurs following pretreatment of the smear layer by chemical means. An increased variability in size and shape of the crystals is also observed when no chemical pretreatment is used. Thus, relative to the number of crystals that form, no chemical pretreatment of radicular dentin is indicated prior to application of ferric oxalate in the treatment of root sensitivity.

Surgical treatment of induced peri-implantitis in the micro pig: clinical and histological analysis.

The purpose of this pilot study was to determine if lost osseous support adjacent to root form implants could be regenerated using a guided tissue regeneration technique. Three fixtures were placed in each edentulous mandibular bicuspid region of two micro pigs. A total of 6 fixtures were placed in each pig. Due to the presence of a pathologic condition, which was in no way related to the research, the results of one pig were not evaluated. Following osseointegration, peri-implantitis were induced by the use of ligatures and a soft diet. Three modalities of treatment were performed. Utilizing a surgical flap approach, one third of the fixtures (one per quadrant) were covered with expanded polytetrafluoroethylene (ePTFE) membrane and submerged under the soft tissue complex. The second group of fixtures were submerged under the soft tissue complex with no ePTFE membrane. The control fixtures along with their abutments were debrided and remained non-submerged. All fixtures were debrided using an air-abrasive polishing system. The osseous defects around the fixtures were measured from a fixed reference point at the time of surgery and after obtaining block sections.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of nicotine on reproduction and attachment of human gingival fibroblasts in vitro.

The ability of fibroblasts to reproduce and attach to teeth is of paramount importance in re-establishing the lost connective tissue attachment after periodontal therapy. This study examined the effect of nicotine, a major component of the particulate phase of tobacco smoke, on human gingival fibroblast (HGF) reproduction and attachment to tissue culture surfaces. Pooled HGF cultures made from explants of gingival biopsies were utilized between passages 5 and 10 and plated in 96-well plates at 1.0 x 10(4) cells per well. Cell numbers were determined using 3-(4,5-dimethylthiazol-2-y)-2,5-diphenyl tetrazolium bromide (MTT), which is a reflection of mitochondrial dehydrogenase activity. The concentrations of nicotine used were 0.025, 0.05, 0.1, 0.2, and 0.4 microM, the average serum concentration for a smoker being approximately 0.1 microM. The effect of continuous nicotine exposure on HGF reproduction was determined by incubating cell cultures and media containing nicotine for up to 48 hours. Residual toxicity was determined by preincubating cells with nicotine for 1 or 6 hours. HGF suspensions and increasing concentrations of nicotine were added together to determine the effect on attachment. Results showed an enhanced effect of nicotine on HGF attachment, with increasing numbers of cells attaching with increasing nicotine concentrations, compared to the control. Low concentrations of nicotine had a stimulatory effect on cell replication, while higher concentrations of nicotine appear to have no significant effect on HGF reproduction. The responses of cells to some concentrations of nicotine may persist after its removal.

The effect of titanium implant abutment surface irregularities on plaque accumulation in vivo.

The purpose of this study was 2-fold to: 1) evaluate in vitro the surface texture of titanium implant abutments after exposure to plastic scalers, an air-powder abrasive system, rubber cup polishing with flour of pumice, and untreated control abutments; and 2) compare plaque accumulation in humans on abutments treated with the above methods. In part I, 5.5 mm abutments were instrumented for 30 seconds per 90 degrees segment with the respective methods. The surface character was compared to untreated controls using SEM at 260X magnification. The control abutments revealed prominent milling marks and small pits; plastic scalers slightly smoothed the milling marks and created microscratches; the air-powder abrasive largely obliterated the milling marks and caused some surface pitting; the rubber cup with flour of pumice removed the milling marks and created a smooth swirl pattern. None of the instrumentation appeared to roughen the surface. In the clinical experiment (part II), four abutments, one of each type, were placed in 12 patients for a period of 7 days, during which the patients performed no oral hygiene. At the end of 7 days, the abutments were retrieved and processed for SEM. A digitizer and software program were used to determine the percent of total abutment surface area covered by plaque. The demarcation of supragingival and subgingival plaque was well delineated. The total mean percent surface area of plaque ranged from 52.06% for the air-powder abrasive to 55.29% for the plastic scalers.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological requirements for material integration.

The recognition that synthetic devices can provide functional replacements for failed teeth, or for previously edentulous areas, has resulted in increased emphasis being placed on understanding of the interactions between synthetic materials and host tissues in order for the success of these devices to be optimized. A key to achievement of an optimal biological interface between the implant and the surrounding tissue is through an understanding of host response to materials. This article reviews the biological requirements for implant-tissue integration, with specific focus on the role of adhesion molecules and cytokines (growth factors) in this process. Adhesion molecule/cytokine interactions are discussed, and in particular the possible role for osteopontin, an adhesion molecule as well as a cytokine, is considered in wound healing. Finally, the causes of peri-implantitis are discussed, and methods of decontamination are presented. The decontamination methods focus on enhancement of cell adhesion and integration to the altered implant surface.

An in vivo study of dentin sensitivity: the relation of dentin sensitivity and the patency of dentin tubules.

Dentin hypersensitivity can be a major problem for periodontal patients. The relationship between dentin hypersensitivity and the patency of dentin tubules in vivo has been established. Thirteen adult patients with teeth scheduled for extraction were selected and a stent fabricated to confirm location of the root surface being examined. Response to a constant air blast was recorded on a numeric pain rating scale (from 0 to 4) during the course of treatment. The tooth surface was initially treated with 0.5 molar EDTA (pH = 7.4), to remove the smear layer and expose tubules. The region was then treated with either a 3% monopotassium-monohydrogen oxalate solution or a 3% sodium chloride solution, both at pH = 2.4. Solutions were prepared to be indistinguishable to the examiner. Response to air was evaluated before and after EDTA treatment and after treatment with a desensitizing agent. The patient was anesthetized and the treated tooth extracted. Specimens were sectioned, critical point dried, sputter coated with gold, and examined under the scanning electron microscope. Photomicrographs were analyzed by computer assisted digital analysis to evaluate the degree of tubule occlusion. Statistical analysis by repeated measures ANOVA for univariate tests of hypothesis for within subject effects showed the sodium chloride solution was more effective in reducing dentin sensitivity than the potassium oxalate solution. Scanning electron micrographic analysis revealed a mean dentin tubule aperture size of 1.720 square microns following EDTA treatment alone, 0.564 square micron following potassium oxalate treatment, and 0.386 square micron following sodium chloride treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioedema as a complication in periodontal surgery: report of a case.

Angioedema is a diffuse swelling of the subcutaneous or submucosal tissues that occurs in both hereditary and non-hereditary forms. It can be a temporarily disfiguring condition, but not usually a serious one unless the airway is compromised. In the majority of cases, no underlying cause can be identified. In this report, a case of "idiopathic" angioedema that occurred while performing a periodontal surgical procedure is presented. This case is interesting because the patient was on long-term use of an angiotensin-converting enzyme [ACE] inhibitor for hypertension, and recent evidence has shown that ACE inhibitors suppress the breakdown of circulating bradykinins. With high plasma levels of bradykinins, a local anesthetic, periodontal surgical procedures, or even emotional stress may trigger an attack of angioedema. Practitioners should be aware of the pharmacologic side effects of ACE inhibitors and be prepared to handle an emergency if a patient's airway becomes compromised.

Microbiologic characterization of ligature-induced peri-implantitis in the microswine model.

The purpose of this study was to evaluate the microbiologic changes associated with induction of peri-implantitis in the microswine. A split-mouth design was utilized. Three implants were placed in the edentulous mandibular bicuspid region of 2 microswine yielding 12 implants for evaluation. The experimental implant abutments were ligated with 4-0 silk suture material to induce peri-implantitis for a period of 45 days. The control implant abutments were not ligated. The control implants were scaled and cleaned at each time interval using plastic scalers. The attachment level (AL), probing depth (PD), gingival index (GI), and plaque index (PI) were measured at day 0 (baseline) and days 14 and 45. Microbiologic samples were taken from the "sulcus" with paper points at each interval and were dispersed in prereduced media; plated on selective and non-selective media; and grown under aerobic, anaerobic, and capnophilic atmospheres. A greater AL, increased PD, and higher GI and PI scores were noted among the experimental implants. The controls remained essentially unchanged. Radiographs revealed that experimental implants showed an increased amount of bone loss when compared to control. Bone loss caused the implant threads to be exposed in the experimental implants. Microbiologic studies revealed that there was a shift from Gram-positive facultative organisms to Gram-negative obligate anaerobes, including black pigmented Bacteroides, in experimental implants. The microbiota of the control implants remained primarily Gram-positive facultative organisms. The microswine appears to be a suitable animal model for evaluation of osseointegrated implants. Importantly, under the experimental conditions reported, osseointegrated implants were susceptible to "periodontal" breakdown or peri-implantitis.

The effect of chlorhexidine treatment of root surfaces on the attachment of human gingival fibroblasts in vitro.

Chlorhexidine mouthrinse is a widely used adjunct in periodontal therapy due to its bactericidal effects. The effect of this agent on chronic gingivitis and wound healing following surgical therapy in animals and humans has been favorable. The re-establishment of lost connective tissue attachment to the root surface following periodontal therapy is a desirable goal in which the ability of periodontal ligament fibroblasts to reattach to root surfaces of periodontally involved teeth is a critical event. Understanding the effect of chlorhexidine on fibroblast attachment will provide the rationale for its use during the healing phase of periodontal surgery. For this study, impacted third molars were sectioned into 4 pieces. Groups of 10 root pieces were exposed to 0.12% chlorhexidine or saline for 3 minutes followed by a distilled water rinse. The root pieces were incubated with human gingival fibroblasts (HGF) using standard tissue culture techniques for 1, 2, 4, 6, and 8 hours. HGF were prelabeled with 3H-thymidine to a standard specific activity. The surface area of each root piece was determined and the attached cells quantified by using scintillation spectroscopy. The number of cells per unit area was then calculated and the data expressed as cells/mm2. The repeated measures design was statistically analyzed by repeated measures analysis of variance. There was a significant difference between the number of attached cells in the chlorhexidine and the control groups (P less than 0.001). Exposure of root surfaces to chlorhexidine significantly inhibits subsequent fibroblast attachment which may interfere with regeneration of the periodontium. Hence, the data suggest that efforts should be made to minimize chlorhexidine contact with the root surface with physical barriers.

A variation from classic oral manifestations associated with acute myeloblastic leukemia. A case report.

A case representing previously misdiagnosed acute myeloblastic leukemia associated with an absence of classical intraoral manifestations is presented. Platelet count was less than 15,000, and hematocrit was 20.3, yet clinical signs were limited to malaise and extreme gingival and mucosal pallor. The typical initial signs of gingival enlargement or hemorrhage never appeared, probably due to excellent plaque control by this patient. Mucosal color changes dictated the need for laboratory studies leading to a rapid and relatively early diagnosis.

The relationship between periodontitis and the maxillary sinus.

This article presents a short review of the literature describing the relationship of periodontal disease and the maxillary sinus. This is followed by two case reports which demonstrate a close physical relationship between molar roots and the sinus and suggest that a sinusitis may develop from the extension of periodontal disease into the maxillary sinus. Further investigation of this hypothesis is necessary.

A histometric evaluation of the effect of citric acid preparation upon healing of coronally positioned flaps in nonhuman primates.

Facial recession defects were created on maxillary canine teeth of six Macaca irus monkeys and left untreated and exposed to oral fluids for 6 to 12 weeks. Notches were placed in the exposed root surfaces at the level of the free gingival margins. Following root planing with the addition of topical citric acid application on experimental surfaces, pedicle flaps were coronally positioned over the previously exposed roots. After euthanasia, block sections representing postsurgical time periods of 0, 3, 7, 14, 21, 28 and 42 days were secured and tissues were processed for histologic evaluation. All citric acid-treated surfaces exhibited new connective tissue attachment of pedicle flaps to previously exposed areas by 14 days with transmission electron micrographs confirming beginning cementum deposition. In contrast, controls demonstrated epithelial migration to, or apical to, reference notches. Although the total number of samples available for statistical comparison was small, a two-tailed t test for correlated samples showed citric acid application did not result in enhanced clinical root coverage, but did result in significantly greater amounts of new connective tissue attachment (P less than 0.05, df = 3). Pedicle flap healing against teeth with devital pulps was identical to that seen in teeth with vital pulps, while citric acid application to root-planed surfaces of vital teeth had no observable effect upon pulpal tissues.

Effect of polylactic acid on replanted teeth in dogs.

An attempt to inhibit root resorption and ankylosis of replanted roots in the mandibles of dogs was made by coating the root segments with a biodegradable compound. Resorption was not inhibited, but ankylosis response was apparently averted until the compound began to degrade.