bluuebunny/crossref_metadata_2025 huggingface dataset:
Topological Differences in the Expression of Collagen Type I and Collagen Type III mRNAs in the Rat Gingiva
Authors: Redlich Meir , Peleg Itzhak , Cooperman Helena , Shoshan Shmuel
Published: March 2012

Collagen mRNA levels in the gingival cells of molars and incisors in rats were measured and correlated with the ratio of interstitial collagen to DNA in these regions. Hybridization of 32P‐labeled specific cDNA probes for collagen types I and III with total RNA isolated from gingival tissue of rat molars and incisors showed that the steadystate levels of mRNAs of type I was significantly higher in the molars than in the incisors (molars/incisors = 2.12±0.12, P <0.004). However, the ratio of interstitial collagen to DNA in the gingiva of the molars was significantly lower than that found in the incisors (collagen/DNA = 4.13±0.90 and 12.89±1.24 respectively, P <0.001). It is suggested that the difference between the mRNA levels and those of interstitial collagen may reflect an intrinsic characteristic presumably associated with the different modes of mastication between molars and incisors of the rat. J Periodontol 1994;65:776–780.
The Effect of Post‐Surgical Flap Placement on Probing Depth and Attachment Level: A 2‐Year Longitudinal Study
Authors: Machtei Eli E. , Ben‐Yehouda Amos
Published: March 2012

Postsurgical flap placement might affect the outcome of the operative procedure. Modified Widman flap surgery with primary closure and flap approximation (usually away from the bone crest) and apically positioned flap surgery with near crestal bone positioning are both widely used in surgical periodontal treatment. Several comparative investigations have studied these modalities, however, none have been able to show conclusively that either is superior to the other. The purpose of this longitudinal study was to explore the optimal postsurgical flap placement in respect to final probing depth and changes in clinical attachment level. Following routine hygienic phase of treatment, 12 subjects (186 teeth) with adult periodontitis received surgical periodontal treatment. Prior to the flap surgery, probing depth and clinical attachment level were recorded. Sounding depth measurements were taken to record postoperative flap placement. Patients were placed on a 3‐month maintenance program. Probing depth and clinical attachment level were again measured at 2 years postoperatively and compared to baseline measurements. An overall positive correlation (R = 0.43; P = 0.0248) was found between immediate postoperative sounding measurements and probing depth after 2 years. Conversely, attachment level changes over the 2‐year period showed only weak inverse correlation (R = 0.27; P = 0.0121) with sounding depth measurement immediately postsurgically. Sites where postoperative sounding depth were ≤ 3 mm had a mean probing depth (2.52 mm) which was significantly (P <0.001) smaller compared to sites with sound depth ≥ 4 mm (3.58 mm). Changes in clinical attachment level varied between sites and sounding depth groups; however, none of these differences were statistically significant. Based on our findings it is suggested that following periodontal flap surgery, in those cases where minimal probing depth is desired, the flap be secured to the underlying structures at or slightly coronally to the bone crest (≤ 3 mm). Such an approach is likely to result in optimal pocket reduction with minimal attachment loss, which when supplemented with maintenance care and personal oral hygiene is likely to remain unchanged and prevent future periodontal relapse. J Periodontol 1994;65:855–858.
Healing Response of Human Buccal Gingival Recessions Treated With Expanded Polytetrafluoroethylene Membranes. A Retrospective Report
Authors: Trombelli Leonardo , Schincaglia Gian Pietro , Scapoli Chiara , Calura Giorgio
Published: March 2012

Twenty‐four (24) deep wide buccal gingival recessions were treated with ePTFE membrane according to guided tissue regeneration principles (GTR). Factors affecting the surgical outcome of the regenerative procedure were retrospectively analyzed. In 16 cases, the barrier membrane was used in conjunction with tetracycline root conditioning and fibrin‐fibronectin system application, and 8 cases were treated with the membrane alone. Healing response was evaluated 12 months after surgery. Since no difference was observed between the two treatment protocols, all available data were grouped. Mean recession depth was reduced from 4.6 mm to 1.3 mm postoperatively, which represents an average root coverage of 71.7%. Fifty percent (50%) of the cases showed clinical attachment gain greater than or equal to 4 mm and a mean increase of keratinized tissue of 1.0 mm was observed. Baseline recession depth and extent of membrane exposure at the reentry procedure significantly influenced the amount of newly‐formed tissue under the membrane. Recession reduction positively correlated with the preoperative recession depth and the regenerated tissue gain. Treatment was also affected by tooth location, recession reduction, and attachment gain, being significantly greater in upper than lower archs. Results suggest that GTR technique represents a predictable procedure to improve the soft tissue conditions of deep mucogingival defects. Randomized controlled trials of other forms of management of mucogingival defects as compared to the GTR technique will be necessary to fully evaluate the utility of the GTR technique. J Periodontol 1995; 66:14–22.
The Influence of Insulin‐Like Growth Factor (IGF) on C19 Steroid Conversions by Human Gingiva and in Cultured Gingival Fibroblasts
Authors: Kasasa S. , Soory M.
Published: March 2012

The metabolic conversion of 14C‐testosterone by human gingival tissue in response to IGF was studied. Androgen metabolic studies were also performed in 5 to 7 celllines of cultured gingival fibroblasts, using 14C‐testosterone and 14C‐4‐androstenedione as initial substrates. Duplicate incubations of gingival tissue were performed after establishing the wet weight, in Eagle's MEM + 10% FCS and optimal stimulatory concentrations of IGF for 24 hours. Similar incubations were performed in duplicate with cell‐line's of gingival fibroblasts, control/IGF, and 14C‐testosterone/14C4‐androstenedione. At the end of the incubation period, the radioactive metabolites were extracted, evaporated, subjected to thin layer chromatography for their separation, and quantified by scanning in a Berthold's linear analyzer. With the gingival tissue samples, IGF caused a 4‐fold increase in 5a‐dihydrotestosterone (DHT) synthesis (n = 5; P < 0.1, Wilcoxon signed rank test for paired observations) and a 3.5‐fold increase in 4‐androstenedione formation (n = 5; P < 0.1) from 14C‐testosterone. When similar incubations were performed with cell‐lines of fibroblasts and 14C‐testosterone, average values of duplicate incubations showed a 2.5‐fold increase in DHT synthesis in response to IGF (n = 7; P < 0.002) and a 2.3‐fold increase in 4‐androstenedione formation (n = 7; P < 0.002). With 14C‐4‐androstenedione as substrate, IGF stimulated a 2.7‐fold increase in DHT synthesis (n = 5; P < 0.1) compared with controls and a 1.8‐fold increase in testosterone formation (n = 5; P < 0.1). Since both DHT and IGF are implicated in protein turnover by fibroblasts, significant stimulation of DHT synthesis by IGF in gingiva and cultured fibroblasts is suggestive of a possible mechanism for mediating inflammatory repair via the androgen metabolic pathway. J Periodontol 1995;66:966–972.
Comparison of the Characteristics of Human Gingival Fibroblasts and Periodontal Ligament Cells
Authors: Ogata Yorimasa , Niisato Naomi , Sakurai Takeshi , Furuyama Shunsuke , Sugiya Hiroshi
Published: March 2012

To elucidate the characteristics of human periodontal ligament cells, we compared these cells with gingival fibroblasts isolated from the periodontal tissues of female human subjects. Human periodontal ligament (HPDL) cells had a sharper spindle shape and exhibited a higher growth rate than human gingival fibroblasts (HGF). HPDL cells had a high level of alkaline phosphatase (ALPase) activity, whereas HGF had a low level of such activity. Northern blot analysis demonstrated that HPDL cells produced ALPase mRNA. Decorin and biglycan mRNA were detected in both HPDL cells and HGF, whereas osteocalcin and bone sialoprotein mRNA was not detected in either cells. Both HPDL cells and HGF responded to Prostaglandin E2 (PGE2) and isoproterenol, and produced cyclic AMP (cAMP), but did not respond to human 1‐34 parathyroid hormone (PTH). Intracellular Ca2+ ([Ca2+]i) was measured in HPDL cells and HGF, using Fura 2‐AM. Bradykinin (BK) and histamine (HIS), which are major chemical mediators, caused a transient rise of [Ca2+]i in the presence of extracellular Ca2+. In HGF, but not HPDL cells, HIS induced a biphasic transient peak in [Ca2+]i. BK and HIS increased PGE2 release in both HPDL cells and HGF. However, HGF released a larger amount of PGE2 than HPDL cells. These results demonstrate that HPDL cells have quite different characteristics from HGF. HPDL cells proliferate at a higher rate than HGF, show higher levels of cAMP production and greater ALPase activity, and respond in a different fashion to chemical mediators (BK and HIS) compared with HGE J Periodontol 1995;66:1025–1031.
Periodontal Files—A Comparative Study
Authors: Pasquini Ricardo , Clark Stephen M. , Baradaran Sharyar , Adams Donald F.
Published: March 2012

Periodontal files are used by many dentists for instrumentation of root surfaces as a part of periodontal treatment. The purposes of this study were: 1) to examine, evaluate, and compare several periodontal files in 3 different conditions: new, used, and used/sharpened and 2) to evaluate the efficacy of 5 sharpening devices. The main characteristics observed included: the number, shape, and interval of blades; the active, rake, and lip angles; changes induced by wear; the influence of sharpening; and the type of metal surfaces comprising the blades. There was a wide range of active angles on each individual file, from a high of 75° to a low of 51°. The range of active angles for all blades on all new files was even greater, from a high of 87° to a low of 30°. Wear, observed on some but not all blades, was not extensive and appeared either as abrasion or, occasionally, as fracture of the blade edge. Sharpness scores (5 = sharpest and 1 = dullest) for new file blades were also extremely variable and spanned the full range of values, with a majority of blades scoring 3.5 and below. Attempts to sharpen files with several devices produced inconsistent results. All 5 sharpening devices had significant shortcomings. It was concluded that the extreme ranges both in active angles and in sharpness scores probably have a significant influence on effectiveness of root instrumentation. J Periodontol 1995;66:1040–1046.
The Apical Border Plaque in Severe Periodontitis. An Ultrastructural Study
Authors: Vrahopoulos Theofilos P. , Barber Pauline M. , Newman Hubert N.
Published: March 2012

This study concerns the apical border (AB) plaque in relation to severe forms of periodontitis (SP), including juvenile, post‐juvenile, and rapidly progressing periodontitis. Twenty‐four (24) teeth from 16 patients with SP were examined by transmission electron microscopy (TEM). The AB was not discrete, with islands of bacteria in the so‐called plaque‐free zone (PFZ). Coronal to the AB the established plaque consisted of a layer of Gram‐positive cocci and ghost cells and a superficial layer mainly of Gram‐negative morphotypes, including cocci, rods, filaments, fusiforms, and spirochetes. The most apical apparently intact organisms in the PFZ were in bacterial islands or in isolation and were predominantly Gram‐negative cocci and rods, with ghost cells in abundance. Ruthenium red, alcian blue‐lanthanum nitrate, and safranin O were used to label matrix polyanionic macromolecules, and periodic acid (thiosemicarbazide) silver proteinate for intracellular polysaccharide (IPS). The matrix components were mainly fibrillar. Many intact bacteria exhibited extracellular polysaccharides or glycocalyces associated with their cell wall, and cytoplasmic IPS granules. The latter varied in distribution and were evident even in the most apically advanced intact microorganisms. The results indicate that IPS and some matrix features of the apical border plaque in severe periodontitis in certain aspects resemble those of sub‐contact area plaque on children's teeth, in health or associated with early chronic gingivitis, and with those in chronic adult periodontitis. They also suggest the establishment of acidic regions in the microniche at the bottom of the periodontal pocket in the various forms of periodontitis differing in rate of progression. It was concluded that there was a limited range of intact bacterial morphotypes in the apical border plaque in severe periodontitis, similar to those in chronic adult periodontitis. J Periodontol 1995;66:113–124.
Mycoplasmas in Plaque and Saliva of Children and Their Relationship to Gingivitis
Authors: Holt Ruth D. , Wilson Michael , Musa Sabri
Published: March 2012

Gingivitis is common in children but its etiology is not well understood. Results of earlier studies have suggested that mycoplasmas may have a role in the disease. In this study two plaque samples and one stimulated saliva sample were taken from each of a group of sixty (60) 5 to 9 year‐old children and cultured selectively for mycoplasmas. Subjects had been selected on the basis of gingival status buccal to the most posterior tooth in an upper quadrant, 20 each having scores 0, 1, or 2 at this site using the Löe and Silness index. Plaque samples were taken from the adjacent tooth surface and from a second posterior site where the adjacent gingiva was free of signs of inflammation. Mycoplasmas were cultured from 54 saliva samples and from 57 plaque samples. Isolation frequency and numbers of mycoplasmas in relation to total anaerobic counts were consistently related to gingivitis scores in both plaque and saliva samples, with higher frequencies and proportions with increasing levels of gingival inflammation at the selected site. In plaque samples this finding held good for both comparisons between groups of subjects and for those between test and control sites within subjects. Findings would appear to confirm the suggestions of earlier studies that mycoplasmas in the oral cavity are associated with gingivitis in children. J Periodontol 1995;66:97–101.
Guided Tissue Regeneration in Severe Periodontal Defects in Anterior Teeth. Case Reports
Authors: Echeverría José J. , Manzanares Cristina
Published: March 2012

Four consecutive chronic, severe periodontal bone defects in anterior teeth were treated by guided tissue regeneration, using a polytetrafluoroethylene periodontal membrane. The root surface was not specifically conditioned, and osseous grafts were not used. However the membrane was manipulated so that space under it was maintained. This was accomplished by painting the outer surface of the membrane with butyl‐cyanoacrylate, so that it became rigid. The membranes were removed after 4 weeks and a bone‐like tissue was found in all cases. The clinical results suggest that there was a relationship between the amount and quality of the new tissue and the volumetric characteristics of the available space. J Periodontol 1995; 66:295–300.
Successful Bone Fill in Late Peri‐Implant Defects Using Guided Tissue Regeneration. A Short Communication
Authors: Hämmerle Christoph H.F. , Fourmousis Ioannis , Winkler James R. , Weigel Christian , Brägger Urs , Lang Nikiaus P.
Published: March 2012

Severe loss of peri‐implant supporting bone traditionally leads to the removal of the affected implant, but this may not be necessary in all cases. This paper presents a novel treatment approach aimed at the successful regeneration of bone lost to peri‐implantitis using guided tissue regeneration (GTR). Four years after implant placement two patients presented with severe peri‐implant tissue breakdown. Clinical signs of disease included bleeding on probing, suppuration, increased probeable pocket depth (4 to 9 mm) and a decreased level of clinical attachment (2 to 10 mm). Radiographic analysis revealed 2.6 to 7.1 mm loss of supporting bone. Treatment of these lesions included raising flaps, wound debridement, and rinsing with sterile saline and 0.2% Chlorhexidine digluconate. Subsequently, ePTFE membranes were adapted around the necks of the implants and the flaps sutured around the necks of the implants, allowing for transmucosal healing. Both patients were placed on a 10‐day antibiotic regimen and instructed to rinse twice daily with a 0.12% Chlorhexidine solution. They were reevaluated every 3 weeks at which time professional plaque control was performed. After 4 1/2 and 6 1/2 months, respectively, the membranes required removal due to infection. The radiographic analysis 1 year after membrane removal revealed 1.5 to 3.6 mm of bone gain. As a result of regenerative therapy the implants in both these patients were successfully maintained. It can be concluded that implants with severe loss of bone resulting from peri‐implantitis need not always be extracted. A potential approach for the treatment of peri‐implant bone destruction is GTR therapy using strict attention to good antimicrobial therapy. J Periodontol 1995; 66:303–308.
Periodontal Microbiota of Mobile and Non‐Mobile Teeth
Authors: Grant Daniel A. , Grant Danielle A. , Flynn M. Jane , Slots Jørgen
Published: March 2012

The mechanism of accelerated periodontal destruction around teeth with occlusal trauma and increased mobility remains unclear. One possibility is that tooth mobility creates a subgingival environment conducive to overgrowth by periodontal pathogens. This study compared the subgingival microflora in mobile and non‐mobile teeth of 35 adults on supportive maintenance therapy and 15 with untreated adult periodontitis. In each subject, subgingival paper‐point samples were obtained from a mobile tooth with a probing depth of 4 mm or greater and from a non‐mobile tooth with similar probing depth and gingival index. Samples were transported in VMGA III medium. Pockets around mobile teeth harbored significantly higher proportions of Campylobacter rectus (P = 0.001) and Peptostreptococcus micros (P = 0.05) than pockets with non‐mobile teeth: Mobile teeth also tended to show elevated levels of Porphyromonas gingivalis, but this did not reach statistical significance. This study suggests that tooth mobility may constitute a risk for periodontal breakdown due to an increased subgingival occurrence of specific periodontopathogens. This hypothesis needs to be verified in longitudinal clinical and microbiological studies. J Periodontol 1995; 66:386–390.
The Possible Association Between Localized Juvenile Periodontitis and Supernumerary Teeth
Authors: Odell Edward W. , Hughes Francis J.
Published: March 2012

Supernumerary teeth and localized juvenile periodontitis in the same patient is a very unusual finding. Only 5 cases are reported, 2 of which were identical twins. An additional 2 cases are presented in which localized juvenile periodontitis was associated with multiple supernumerary premolars. These cases are strikingly similar to 3 of the previously reported cases, raising the possibility that this combination of disorders may be more than a chance association. J Periodontol 1995;66:449–451.
Devices for Dentoalveolar Regeneration: An Up‐To‐Date Literature Review
Authors: Hardwick Ross , Hayes Byron K. , Flynn Charles
Published: March 2012

Regeneration of periodontal and alveolar ridge defects utilizing barrier membranes has become well established in clinical dentoalveolar reconstruction. Application of this technique has evolved from the concept of separating tissues during healing to that of providing a healing environment capable of regeneration of functional structures. The biomaterial characteristics and design of membranes employed in this technique play an important role in establishing and maintaining this environment. Barrier membranes must incorporate specific features that address the biological, mechanical, and clinical use requirements involved in regenerative treatment. Although nondegradable materials require a second surgical procedure for removal, these materials simplify certain aspects of development, production, and clinical regenerative treatment for some applications. Degradable materials introduce specific considerations and limitations regarding material selection, design, and clinical application. The progressive breakdown of degradable membranes results in dynamic changes in the mechanical and biocompatibility profiles of these materials. With present technology, these factors may limit use of degradable materials to specific applications. Membrane materials, therefore, should be selected based on a thorough understanding of the benefits and limitations inherent to the material(s) in relation to the functional requirements of specific clinical applications. J Periodontol 1995;66:495–505.
Immunohistochemical Expression of Extracellular Matrix Components of Normal and Healing Periodontal Tissues in the Beagle Dog
Authors: Matsuura Masahiro , Herr Yeek , Han Kyung‐Yun , Lin Wen‐Lang , Genco Robert J. , Cho Moon‐Il
Published: March 2012

Periodontal regeneration requires formation of periodontal tissues lost due to periodontal disease. To better understand the formation of new periodontal tissues during periodontal repair and regeneration, immunohistochemical expression of extracellular matrix components of normal as well as healing periodontal tissues was evaluated and compared using the avidin‐biotin complex immunohistochemical technique. For this purpose, horizontal furcation defects were created around mandibular P2 and P4 of 6 dogs after extraction of P1 and P3. The root surfaces were conditioned with citric acid and expanded polytetrafluoroethylene (ePTFE) membranes were placed and retained 0.5 mm above the cemento‐enamel junction. The mucoperiosteal flaps were sutured in a coronal position. Two animals were sacrificed at 2, 4, and 8 weeks, and mesio‐distal tissue slices containing normal or healing periodontal tissues were demineralized, dehydrated, and embedded in paraffin. Immunohistochemical localization of type I collagen (CI), fibronectin (FN), secreted protein, acidic and rich in cysteine (SPARC), vitronectin (VN), and bone sialoprotein (BSP) was performed on 6 μm thick sections. Morphological results demonstrated that at 2 weeks after defect creation, lesions were filled primarily with granulation tissue which was gradually replaced by newly‐formed fibrous connective tissue, periodontal ligament (PDL), cementum, and bone between 4 and 8 weeks. The results of immunohistochemical study revealed that at 2 weeks the granulation tissue, especially in the intercellular spaces of inflammatory cells, was intensively stained for FN and VN. At 4 and 8 weeks, staining for CI, FN, and VN was found in fibrous connective tissue, the newly‐formed PDL, cementum, and osteoid. Further the attachment zone of the PDL collagen fibers to cementum showed intense staining for FN. Immunostaining for SPARC was positive in the new PDL, cementum, and bone, while staining for BSP was restricted to the new cementum and bone. Interestingly, the PDL, especially in areas adjacent to active bone formation, demonstrated intense staining for BSP. However, fibrous connective tissue and PDL proper were unstained for BSP. These results indicate that FN and VN are involved in the early stages of periodontal repair, and periodontal regeneration is achieved through formation of periodontal tissues that are composed of different matrix components specific to different types of periodontal tissues. J Periodontol 1995; 66:579–593.
Planning for the Manpower Needs for the Next Generation of Periodontal Patients
Authors: Waldman H. Barry
Published: March 2012

Projections by the bureau of the census indicate that there will be an additional 55.6 million people 20 years and older living in this country by the year 2020. Estimates are developed for each state and region of the needed numbers of periodontists to maintain current practitioner levels. The availability of needed practitioners is considered in terms of the number of graduates from periodontal training programs. A short‐fall is projected in the number of training program graduates needed to maintain current periodontist‐to‐population ratios by 2020. J Periodontol 1995;66:599–604.
A Comparative Study of ePTFE Periodontal Membranes With and Without Decalcified Freeze‐Dried Bone Allografts for the Regeneration of Interproximal Intraosseous Defects
Authors: Mellado Jose R. , Salkin Leslie M. , Freedman Arnold L. , Stein Marc D.
Published: March 2012

A comparative study which evaluated two treatment modalities for regeneration of interproximal periodontal lesions was conducted. Eleven pairs of advanced periodontal lesions in 11 human subjects (6 male and 5 female) were treated in a split mouth design with expanded polytetrafluoroethylene (ePTFE) interproximal membranes alone (control) in one lesion and ePTFE interproximal membranes in combination with decalcified freeze‐dried bone (test) in the other lesion. At 1 year posttreatment, both treatment modalities revealed a significant increase in clinical attachment levels from baseline (2.0 ± 1.37 mm test, 2.0 ± 0.88 mm control) with no significant differences between the two modalities. When the amount of new bone formed in these lesions was assessed using re‐entry procedures, a significant difference in new bone formation from baseline was found only for lesions treated with ePTFE alone (0.4 ± 0.78 mm test, 1.3 ± 0.96 mm control). It was concluded that at 1 year post‐treatment, significant clinical attachment gains could be obtained by the use of ePTFE barriers with or without DFDBA. Statistically significant results in bone fill were only found when ePTFE barriers were used alone. J Periodontol 1995;66:751–755.
Interleukin‐1β Gene Expression in Human Oral Polymorphonuclear Leukocytes
Authors: Hendley Thomas M. , Steed R. Britt , Galbraith Gillian M.P.
Published: March 2012

Oral polymorphonuclear leukocytes (pmn) were obtained from 10 adult donors in good oral health using a method employing repeated mouth rinse collection. Interleukin‐1β (IL‐1β) mRNA was detected in freshly obtained cells by blot hybridization of total cellular RNA with a biotin labeled cDNA probe. Supernates from oral PMN placed in culture for 3 hours contained substantial amounts of IL‐1β measured by ELISA. Significantly greater numbers of PMN and amounts of PMN‐derived IL‐1β were obtained from the same donors 2 hours subsequent to an oral sucrose challenge (3.23 × 106 vs. 1.57 × 106 mean PMN number, P = 0.004; 59.80 vs. 20.05 mean pg/ml IL‐1β, P = 0.036, respectively). However, the elevated levels of IL‐1β were due to the higher cell number rather than to increased production by individual cells. Stimulation of oral PMN with recombinant granulocyte‐macrophage colony stimulating factor did not enhance their cytokine production. In most instances, IL‐1β production by oral PMN was dramatically greater than that of their blood counterparts. These findings suggest that oral PMN are an important source of IL‐1β, which plays a central role in oral immunity and inflammatory disease states. J Periodontol 1995; 66:761–765.
Clinical and Microbiological Observations of Early Polytetrafluoroethylene Membrane Exposure in Guided Bone Regeneration. Case Reports in Primates
Authors: Fritz Michael E. , Eke Paul I. , Malmquist Jay , Hardwick Ross
Published: March 2012

Premature membrane exposure at one week is described in 3 Macaca mulatta monkeys as part of a sequence of experiments on guided bone regeneration. Clinical sequelae include redness, edema, and tissue slough. Bacteroides fragilis, Streptococcus pneumoniae, Prevotella intermedia, and Staphylococcus intermedius were detected at all prematurely exposed sites. Pseudomonas maltophilia, Strepi, pneumoniae, and P. intermedia were the predominant organisms detected and consisted of more than 10% of the total anaerobic count. J Periodontol 1996;67:245–249.
Effectiveness of Subgingival Scaling and Root Planing: Single Versus Multiple Episodes of Instrumentation
Authors: Anderson Gissela B. , Palmer John A. , Bye Fred L. , Smith Billy A. , Caffesse Raul G.
Published: March 2012

This study evaluates the effectiveness of subgingival scaling and root planing comparing the effect of a single instrumentation to the effect of three instrumentations. A total of 35 teeth in 15 patients were selected; 15 were scaled once (Group A), 15 were scaled three times (Group B), and 5 were used as controls (Group C), representing teeth that were not instrumented. The Group A and B teeth were chosen in the same patient based on random selection. All the teeth were scored by the calculus index of the periodontal disease index. Six surface locations were probed to determine probing depth. The level of the gingival margin was marked on the teeth to locate supra‐ and subgingival calculus after extraction. The Group A and B teeth received the initial episode of scaling and root planing for not more than 10 minutes, then only the Group B teeth received two additional instrumentations of not more than 5 minutes each. The additional instrumentations were performed 24 hours after the initial scaling. The scaled and control teeth were extracted immediately after the third instrumentation period. The teeth were washed with water and stained with methylene blue. They were viewed under a stereomicroscope which had a tenth grid on its eyepiece. Assessments were made involving the total counts and percents of the surfaces covered with calculus on the scaled and unsealed teeth. The results demonstrated no significant difference in the effectiveness of calculus removal between single and multiple episodes of scaling and root planing. Similar results were found for the total amount of calculus removed, the calculus removed from individual surfaces, and the calculus removed from various probing depth levels. J Periodontol 1996;67:367–373.
Alveolar Ridge Preservation Following Extraction of Maxillary Anterior Teeth. Report on 23 Consecutive Cases
Authors: Nemcovsky Carlos E. , Serfaty Vidal
Published: March 2012

The purpose of this article was to clinically evaluate the predictability of a surgical procedure to preserve the alveolar ridge after extracting maxillary anterior teeth with advanced bone loss. This procedure is indicated when a tooth‐supported fixed partial denture will rehabilitate the area. Non‐resorbable hydroxyapatite crystals are used as graft material and a rotated pediculated split thickness palatal flap covers them. Twenty‐three patients who were treated with this procedure were followed for 12 to 24 months. Results were predictable with minimal postoperative ridge deformation. Indications for this procedure are discussed. J Periodontol 1996;67:390–395.
The Effect of Periodontal Treatment on Periodontal Bacteria on the Oral Mucous Membranes
Authors: Danser Monique M. , Timmerman Mark F. , van Winkelhoff Arie J. , van der Yelden Obele
Published: March 2012

The aim of this study was to investigate the effect of conventional periodontal treatment on the prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia on oral mucous membranes in patients with periodontitis. Fifteen patients were selected with moderate to severe periodontitis (mean age: 39.8 years, range: 26 to 58). From each patient the 4 deepest sites with bleeding on probing were selected for clinical and microbiological evaluation. At baseline, 6 weeks after oral hygiene instruction and extensive scaling and root planing, and 3 months after periodontal surgery, clinical parameters and microbiological samples including saliva, oral mucous membranes, and supra‐ and subgingival plaque were evaluated for the presence of the 3 test bacteria using indirect immunofluorescence. All clinical variables, except redness, showed a significant improvement after surgery. After treatment, the subgingival prevalence of the 3 putative periodontal pathogens had decreased significantly. However, almost no concomitant reduction in the prevalence of the bacteria was seen on the oral mucous membranes. This suggests that the oral mucous membranes may serve as a source for reinfection of the periodontium after treatment. J Periodontol 1996;67:478–485.
Human Papillomavirus in a Patient With Severe Gingival Overgrowth Associated With Cyclosporine Therapy.
Authors: Sağlam Funda , Onan Utku , Soydinç Mahtaban , Yilmaz Oya , Kiraç Kaan , Sever Mehmet Şükrü
Published: March 2012

Cyclosporin A is an endecapeptide that has been used clinically since 1978 as an immunosuppressant agent. Although cyclosporine appears to be uniformly beneficial in the treatment of a wide variety of disorders, its use may result in a number of side effects. One of the most important adverse effects is gingival overgrowth. This report relates a case of severe gingival overgrowth in a 31‐year‐old female who had received cyclosporine therapy in conjunction with a kidney transplant. Because of the severe gingival overgrowth, we analyzed a biopsy, which was positive for human papillomavirus. The case was treated and followed for 18 months. J Periodontol 1996;67:528–531.
Papillon‐Lefèvre Syndrome. Analysis of Neutrophil Chemotaxis
Authors: Firatli Erhan , Tüzün Binnur , Efeoğlu Ahmet
Published: March 2012

Papillon‐Lefèvre syndrome (PLS) is described as the association of palmar‐plantar hyperkeratosis with precocious periodontal disease which results in exfoliation of primary and permanent dentitions. This study was planned to assess the Chemotaxis of peripheral blood neutrophils in 7 patients (3 females and 4 males) with Papillon‐Lefèvre syndrome. The neutrophil Chemotaxis was analyzed using the zymosan activated serum (ZAS) assay. Chemotaxis and spontaneous migration measurements were compared to those of the healthy control subjects. The peripheral blood neutrophil Chemotaxis and spontaneous migration were depressed in all patients with Papillon‐Lefèvre syndrome. The decreased Chemotaxis of peripheral blood neutrophils strongly suggests that the neutrophils may act as one of the important key determinants in the pathogenesis of severe periodontal destruction in patients with PLS. J Periodontol 1996;67:617–620.
The Use of a Resorbable Membrane in Mucogingival Surgery. Case Series
Authors: Rachlin G. , Koubi G. , Dejou J. , Franquin J.C.
Published: March 2012

A surgical technique involving a resorbable membrane was used to treat 3 to 7 mm localized human buccal recessions on 10 consecutive patients. The exposed root surface was scaled and a trapezoidal mucoperiosteal flap was elevated after de‐epithelization of the papillae. The space between the root and the membrane was created using a bur to form a concavity on the root and by bending the membrane with a suture. The flap was positioned as coronally as possible covering the membrane. The sutures were removed 15 days postsurgery and tetracycline therapy prescribed for 10 days. The results were evaluated at 12 months. The surgical procedure resulted in a significant reduction in recession (2.9 mm ± 1.3) as well as a gain in attachment (3.4 mm ± 2.1). Calculation of mean root coverage was 59.6%. There was no significant change of the keratinized tissue width. For therapeutic reasons, re‐entry was performed in 2 cases: newly formed tissue was observed on the previously exposed roots. Guided tissue regeneration using a resorbable membrane appears to provide good results in cases of localized buccal recession. J Periodontol 1996;67:621–626.
Osseointegrated Implants in Patients Treated for Generalized Severe Adult Periodontitis. An Interim Report
Authors: Mengel Reiner , Stelzel Michael , Hasse Christof , Flores‐de‐Jacoby Lavin
Published: March 2012

This study presents oral rehabilitation with osseointegrated implants in partially edentulous patients treated for generalized severe adult periodontitis. Five female patients aged between 31 and 44 received a total of 36 implants and were observed for 1 year after insertion of the superstructure. Three months before implantation, venous blood samples were taken from the patients and five periodontally healthy controls, and the serum examined with highly sensitive ELISA test kits for interleukin 1ב (IL1β) and interleukin 6 (IL‐6). Clinical examination covered the plaque index (PI) and gingival index (GI) at teeth and implants plus probing depth (PD) and clinical attachment level (CAL) at the teeth. Microbiological evaluation of teeth and implants was performed by dark‐field analysis, and DNA analysis was performed in addition 1 year after insertion of the superstructure. Radiological controls of the teeth were carried out with standard single‐tooth films in the 2 years preceding implantation and at baseline. Following implantation, further controls of the teeth and implants were undertaken immediately after insertion of the superstructure and 1 year thereafter. The immunological examination revealed that the IL‐1β (0.22 ± 0.2 pg/ml) (means ± SD) and IL‐6 (2.27 ± 2.8 pg/ml) level was slightly, but not significantly, higher in the patients than in the control group (IL‐1β: 0.06 ± 0.06 pg/ml and IL‐6: 0.64 ± 0.2 pg/ml) (P > 0.05). The clinical results show that the GI at the teeth rose slightly from 0.0 to 0.2, and at the implants from 0.3 to 0.4. The PI rose slightly from 0.3 to 0.7 at the teeth and from 0.2 to 0.9 at the implants. Neither the GI nor the PI revealed any significant difference between teeth and implants. Clinical attachment loss at the teeth was minimal at 4.7 to 4.8 mm. Comparison between the teeth and the implants revealed no essential difference in bacterial flora; neither Actinobacillus actinomycetemcomitans nor Porphyromonas gingivalis was recorded at any location. Small quantities of Prevotella intermedia were detected at the teeth and implants of one patient. Radiological evaluation 1 year after insertion of the superstructure revealed a mean bone loss of 0.62 mm at the implants. The bone loss at the teeth during the same period was 0.3%, whereas it had been 1.5% in each of the 2 previous years. These results suggest that there is only a slight difference between the periodontal and periimplant areas in patients with generalized severe adult periodontitis. The full potential for implants in these patients, however, needs to be shown in controlled longitudinal studies. J Periodontol 1996;67:782–787.
Clinical Evaluation of Demineralized‐Unicortical‐Ilium‐Strips for Guided Tissue Regeneration
Authors: Yamaoka Scott B. , Mellonig James T. , Meffert Roland M. , Arnold Ralph M. , Nummikoski Pirkka V. , Mealey Brian L.
Published: March 2012

This study compared demineralized‐unicortical‐ilium‐strips (DUIS) and an expanded polytetrafluoroethylene (ePTFE) physical barrier in combination with decalcified freeze‐dried bone allograft (DFDBA) for treatment of Class II mandibular furcations. Twenty patients with adult periodontitis and at least 2 furcation invasions participated in this study. Probing depth (PD), clinical attachment level (CAL), and bone fill were measured at 6 and 12 months. Standardized radiographs were analyzed using computer assisted densitometric image analysis (CADIA). Fifteen of 20 patients completed the 12‐month evaluation. At 6 months both control and test groups showed significant reductions in PD from baseline (P < 0.01). PD reduction for the ePTFE + DFDBA sites was 2.13 mm ± 1.25, and the DUIS + DFDBA, 1.77 mm ± 1.21. CAL at 6 months was sustained to 12 months when the net gains in CAL for ePTFE + DFDBA being 1.30 mm ± 1.45 (P < 0.01) and for DUIS + DFDBA sites 1.13 mm ± 1.68 (P < 0.02). The horizontal furcation PD decreased 2.87 mm ± 1.68 (P < 0.01) in the ePTFE + DFDBA and 1.70 mm ± 1.69 (P < 0.01) for DUIS + DFDBA sites over 12 months. The evaluation of the hard tissue response at the 12‐month re‐entry demonstrated a bone fill of 2.37 mm (75%) ± 2.04 (P < 0.01) with ePTFE + DFDBA and 1.83 mm (79%) ± 1.57 (P < 0.01) with DUIS + DFDBA. DUIS material and ePTFE showed significant improvements in clinical parameters and neither material proved to be significantly better. However, a larger sample size may have permitted us to demonstrate statistically significant differences between the materials. The positive results from the utilization of DUIS for GTR and the advantage of its bioresorbability warrant further investigation. The study found limitations in the use of CADIA for evaluation of guided tissue regeneration in furcations. J Periodontol 1996;67:803–815.
Waterflood Management Based on Well Allocation Factors for Improved Sweep Efficiency: Model Based or Data Based?
Authors: Shahvali M. , Shirzadi S. G. , Ballin P. R. , Ziegel E.
Published: March 2012

Streamline-based methods provide an effective model-based tool for assessing flow patterns and well allocation factors. This type of diagnostic information is a key enabler in model-based waterflood management. Alternatively, data-driven techniques are available for waterflood diagnostics and estimating injector/producer connectivity, including one based on the Capacitance-Resistivity Model (CRM). The purpose of this paper is to compare the results of these two complementary approaches using a sector area representative of a mature field.

In the first part of the paper, a workflow which allows a comparison of the streamlines and the CRM methodologies, regardless of the uncertainty of the simulation model, is introduced. The limitations of both approaches are discussed.

In the second part of the paper, the CRM data-driven approach is used to determine the statistically significant allocation factors for the injection and production data from the sector reservoir model, and they are compared with the streamline-based factors. The results and guidance for the integration of the two approaches are presented.
Creating Digital Thermal EOR Projects Using Wireless Technology and New Data Integration Solutions
Authors: Angelo Christopher , Mershon Kevin
Published: March 2012

Technology over the last decade has revolutionized information systems and how data are collected and shared in our daily lives. An extraordinary amount of data is being collected, stored, analyzed, and shared every day. The oil and gas industry is no stranger to data collection and analysis, but data acquisition and management has historically been complex and expensive and, thus, slowly implemented. With recent advances in hardware and software, costs have plummeted to yield rapid implementation of sophisticated monitoring, analysis, and easy sharing of information in oilfield projects.

The thermal-enhanced oil recovery (TEOR) process requires constant monitoring and analytical management of wells and facilities. This data management process requires large amounts of data to be collected, correlated and acted-upon on a very frequent basis, resulting in easily-recognizable business benefits by oil producers. This paper reviews the use of wireless instrumentation and integrated data collection systems for digitally managing oilfields, with one such implementation being reviewed.

An independent oil producer using wireless instrumentation and state-of-the-art data integration technology has beenoperating the largest Wireless HART network in the United States since the beginning of 2010. This independent oil producer is wirelessly monitoring all of their steam injectors in three thermal oil fields located in western Kern County, California.
Monobore Well Design: Utilizing Technology to Improve Well Execution Efficiency
Authors: Randell Ben
Published: March 2012

Chevron has piloted a new well design for near-vertical steamflood producers in the MWSS field. This new design simplifies the well construction process by replacing two hole sizes and two casing strings with a single hole size and single combo casing string. Doing so requires utilizing technologies such as: expansion joint, annular casing packer and cementing stage tool to allow only the top portion of the casing string to be cemented while the slotted casing remains un-cemented.

This well design has been piloted in MWSS to replace the previous two-string slotted liner well design. At the time of writing, 26 monobore wells have been installed incident-free and all are a technical success. Chevron has committed to 11 more monobore wells in the nearby Cymric field and is planning to adopt the design throughout its San Joaquin Valley (SJV) fields, with over 70 wells expected by Q3 2012.

The monobore design has reduced overall well construction cycle time by 25% and capital expenditure has also been reduced. The implications to well deliverability and accelerated production are obvious and Chevron has begun to increase the well count in specific campaigns to reflect the time and cost savings. Furthermore, the monobore design increases the probability of logs and casing reaching bottom in a single trip, and enhances formation evaluation to include upper zones that would have been behind casing with the previous design. By implementing the monobore design, Chevron will be able to extend the economic development life of the region.

The subject matter will be of interest to other operators drilling similar, shallow, low-pressure, heavy-oil reservoirs.
Detecting Shale Discontinuity between Different Layers Using Waterflood Tomography
Authors: Lin Yenting , Ortega Antonio , Tafti Tayeb Ayatollahy , Ershaghi Iraj
Published: March 2012

This paper presents a novel signal processing method to detect the existence and location of shale discontinuities between layers with distinct permeabilities by using only waterflood injection and production data. Continuing the work by Y. Lin, et. al (SPE-132699-PP), we use a new waterflood tomography concept to analyze cross-flow behavior among different layers and estimate the hydraulic transmissivity via tomography mapping. With designed injection rates, we estimate the response times at the producers by monitoring production rates. The response time represents the ‘cost’ for the fluid to travel between well-pairs and we can use it to model the virtual path through different layers. We consider the case of waterflooding in the presence of permeability contrast in different layers. The fluid in the low permeability layer tends to flow through the shale discontinuity to the higher permeability layer thus forming vertical `high permeability cross-flow channels between the wells. With the response time, we are able to identify these 3D high perm channels to estimate the location of shale discontinuities causing the cross-flow. To the best of our knowledge, we are the first to propose this waterflood tomography method. Without significantly affecting daily operation and without the cost associated with tracer testing and seismic tomography, our technique only involves applying scheduled changes to the injection rates and analyzing the relationship between these changes and those in production rates.

To demonstrate the application, using a commercial simulator, we build a double layer reservoir model with different permeabilities. We test a line drive case with injectors and producers having perforations in both lower and upper layers. By applying our designed injection and shut-in schedule, we show our method can provide a very accurate estimate of shale discontinuity location by recording accurate response times between well-pairs.