bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Associated With Radiographic Vertical Bone Loss Around Implants Placed in a Clinical Study
Authors: Manz Michael C.
Published: February 2005

The loss of vertical bone height over time has been assessed radiographically as part of the Dental Implant Clinical Research Group studies. Radiographs were assessed from implant placement, uncovering surgeries, and recall appointments. Overall, the study implants experienced most peri‐implant vertical bone loss in the first year after placement, followed by a dramatic decrease in bone loss rate through the subsequent study intervals. Stratified analysis of data up to 72 months after implant uncovering indicates different bone loss patterns by: 1) arch; 2) jaw region; 3) case type; 4) bone quality; 5) surface type; 6) implant design; 7) smoking status; and 8) postoperative antibiotic treatment. These results will be used to build statistical mixed models to indicate which clinical factors are most predictive of peri‐implant vertical bone loss, controlling for confounding and accounting for correlation of data over time and within study patients. Ann Periodontol 2000;5:137‐151.
Implant Survival in Patients With Type 2 Diabetes: Placement to 36 Months
Authors: Morris Harold F. , Ochi Shigeru , Winkler Sheldon
Published: February 2005

Background: Because the life expectancy of individuals continues to increase, dentists providing dental implant treatment can expect to see an increasing number of patients with diabetes mellitus. Today, there are little data available concerning the clinical outcomes involving the use of implant treatment for patients with diabetes mellitus. There are three types of diabetes mellitus: Type 1 (insulin dependent), Type 2 (non‐insulin dependent), and gestational. Because of possible complications from patients with diabetes mellitus, they are excluded from participation in most clinical studies of endosseous dental implant survival.

Methods: This study attempted to determine if Type 2 diabetes represents a significant risk factor to the long‐term clinical performance of dental implants, using the comprehensive DICRG database. Diabetes was a possible exclusion criterion; however, the final decision on Type 2 patients was left to the dental implant team at the research center. A total of 2,887 implants (663 patients) were surgically placed, restored, and followed for a period of 36 months. Of these, 2,632 (91%) implants were placed in nondiabetic patients and 255 (8.8%) in Type 2 patients. Failures (survival) were compared using descriptive data. Possible clustering was also studied.

Results: A model assuming independence showed that implants in Type 2 patients have significantly more failures (P = 0.020). However, if correlations among implants within the patient are considered, the significance level becomes marginal (P = 0.046). The experience of the surgeon did not produce a clinically significant improvement in implant survival. The use of chlorhexidine rinses following implant placement resulted in a slight improvement (2.5%) in survival in non‐Type 2 patients and a greater improvement in Type 2 patients (9.1%); the use of preoperative antibiotics improved survival by 4.5% in non‐Type 2 patients and 10.5% in Type 2 patients. The use of HA‐coated implants improved survival by 13.2% in Type 2 diabetics.

Conclusion: Type 2 diabetic patients tend to have more failures than non‐diabetic patients; however, the influence was marginally significant. These findings need to be confirmed by other scientific clinical studies with a larger Type 2 diabetic sample size.Ann Periodontol 2000;5:157‐165.
The Influence of Preoperative Antibiotics on Success of Endosseous Implants at 36 Months
Authors: Laskin Daniel M. , Dent C. Daniel , Morris Harold F. , Ochi Shigeru , Olson John W.
Published: February 2005

The benefits of prophylactic antibiotics are well recognized in dentistry. However, their routine use in the placement of endosseous dental implants remains controversial. As part of the comprehensive Dental Implant Clinical Research Group (DICRG) clinical implant study, the preoperative or postoperative use of antibiotics, the type used, and the duration of coverage were left to the discretion of the surgeon. These data for 2,973 implants were recorded and correlated with failure of osseointegration during healing (Stage 1), at surgical uncovering (Stage 2), before loading the prosthesis (Stage 3), and from prosthesis loading to 36 months (Stage 4). The results showed a significantly higher survival rate at each stage of treatment in patients who had received preoperative antibiotics. Ann Periodontol 2000;5:166‐174.
Periodontal Diseases and Osteoporosis: Association and Mechanisms
Authors: Wactawski‐Wende Jean
Published: February 2005

There is increasing evidence that osteoporosis, and the underlying loss of bone mass characteristic of this disease, is associated with periodontal disease and tooth loss. Periodontitis has long been defined as an infection‐mediated destruction of the alveolar bone and soft tissue attachment to the tooth, responsible for most tooth loss in adult populations. Current evidence including several prospective studies supports an association of osteoporosis with the onset and progression of periodontal disease in humans. The majority of studies have shown low bone mass to be independently associated with loss of alveolar crestal height and tooth loss. However studies that focus on the relation of clinical attachment loss and osteoporosis are less consistent. To date, the majority of studies on the relationship between periodontal disease and osteoporosis have been hindered by small sample sizes, limited control of other potential confounding factors, varying definitions of both periodontal disease and osteoporosis, and few prospective studies where the temporality of the association can be established. Potential mechanisms by which host factors may influence onset and progression of periodontal disease directly or indirectly include underlying low bone density in the oral cavity, bone loss as an inflammatory response to infection, genetic susceptibility, and shared exposure to risk factors. Systemic loss of bone density in osteoporosis, including that of the oral cavity, may provide a host system that is increasingly susceptible to infectious destruction of periodontal tissue. Studies have provided evidence that hormones, heredity, and other host factors influence periodontal disease incidence and severity. Both periodontal disease and osteoporosis are serious public‐health concerns in the United States. Prevalence of both osteoporosis and tooth loss increase with advancing age in both women and men. Understanding the association between these common diseases and the mechanisms underlying those associations will aid health professionals to provide improved means to prevent, diagnose, and treat these very common diseases. This paper reviews the current evidence on the association between periodontal disease and osteoporosis. Ann Periodontol 2001;6:197‐208.
The Periodontal‐Systemic Connection: Implications for Treatment of Patients With Osteoporosis and Periodontal Disease
Authors: Krall Elizabeth A.
Published: February 2005

Osteoporosis and osteopenia may influence periodontal disease and tooth loss. Medications such as hormone replacement therapy and nutritional supplements that are used to prevent or treat osteoporosis have been evaluated for beneficial effects on oral health in a small number of human studies. Hormone replacement therapy (HRT), which slows the rate of bone loss at skeletal sites such as the hip and spine, also appears to reduce the rate of alveolar bone loss in postmenopausal women. HRT use is consistently associated with greater tooth retention and a reduced likelihood of edentulism in studies of elderly women. The number of studies on the effects of calcium or vitamin D intake on oral outcomes is limited, but suggest that higher intake levels are associated with reduced prevalence of clinical attachment loss and lower risk of tooth loss. Data from a prospective study of oral health in men show a similar association between higher calcium intake and reduced alveolar bone loss. The number of teeth with progression of alveolar bone loss over a 7‐year period was significantly lower among men whose calcium intake was at least 1,000 mg per day, compared to men with a calcium intake below this level. Future studies should confirm these findings and evaluate the oral effects of new medications for osteoporosis. If confirmed, the implications for dental professionals may include an expanded array of medications for the treatment of periodontal disease and a greater emphasis on nutrition education for patients. Ann Periodontol 2001;6:209‐213
The Role of Inflammatory and Immunological Mediators in Periodontitis and Cardiovascular Disease
Authors: De Nardin Ernesto
Published: February 2005

Epidemiological studies have implicated periodontitis (PD) as a risk factor for development of cardiovascular disease (CVD). Persistent infections such as periodontitis induce inflammatory and immune responses which may contribute to coronary atherogenesis, and, in conjunction with other risk factors, may lead to coronary heart disease (CHD). In this review, mechanisms are described that may help explain the association between periodontal infections and CHD. Periodontal diseases are bacterial infections associated with bacteremia, inflammation, and a strong immune response, all of which may represent significant risk factors for the development of atherogenesis, CHD, and myocardial infarction (MI). Several mechanisms may participate in this association, including those induced by oral organisms, and those associated with host response factors. This review will focus on host factors. Oral pathogens and inflammatory mediators (such as interleukin [IL]‐1 and tumor necrosis factor [TNF]‐α) from periodontal lesions intermittently reach the bloodstream inducing systemic inflammatory reactants such as acute‐phase proteins, and immune effectors including systemic antibodies to periodontal bacteria. This review will describe the potential role of various inflammatory as well as immunologic factors that may play a role in periodontitis as a possible risk factor for CHD. Ann Periodontol 2001;6:30‐40.
Role for Periodontal Bacteria in Cardiovascular Diseases
Authors: Kuramitsu Howard K. , Qi Mingshan , Kang In‐chol , Chen Wen
Published: February 2005

Background: Several epidemiological studies as well as a recent animal model approach have suggested a role for periodontal diseases in the development of cardiovascular disease (CVD). This relationship could be mediated by inflammatory responses induced by periodontal pathogens as well as direct interaction of these organisms with cardiac tissue.

Methods: In order to explore these possibilities, the effects of the periodontal pathogen Porphyromonas gingivalis on cellular events proposed to play a role in CVD were investigated.

Results: P. gingivalis, as well as its outer membrane vesicles (OMV), was able to induce foam cell formation (an important characteristic of CVD) in the murine macrophage cell line J774 A.1. This property appears to be mediated by the lipopolysaccharide (LPS) fraction of the cells. Several other oral bacteria were also able to induce foam cell formation. Furthermore, since the rupture of the fibrous cap of plaque appears to be an important factor in acute coronary syndrome, it was demonstrated that P. gingivalis 381 degraded fibrous caps isolated from autopsy samples. In addition, it was observed that strain 381 strongly induced matrix metalloproteinase (MMP)‐9 protease activity, implicated in plaque rupture, from the J774 A.1 macrophages. Finally, strain 381 was able to enhance monocyte chemoattractant protein‐1 (MCP‐1) and NADH oxidase expression from endothelial cells.

Conclusions: Therefore, P. gingivalis exhibits several properties which could play a role in CVD as mediators of LDL oxidation, foam cell formation, and rupture of atherosclerotic plaque. Ann Periodontol 2001;6:41‐47.
Oral Bacteria and Respiratory Infection: Effects on Respiratory Pathogen Adhesion and Epithelial Cell Proinflammatory Cytokine Production
Authors: Scannapieco Frank A. , Wang Bingyan , Shiau Harlan J.
Published: February 2005

Several microbiologic and epidemiologic studies have suggested an association between dental plaque, poor oral health, and respiratory diseases such as nosocomial pneumonia and chronic obstructive pulmonary disease (COPD). A number of hypotheses are suggested to help explain how oral bacteria may participate in the pathogenesis of respiratory infection. Resident bacteria in oral secretions are likely aspirated along with respiratory pathogens and may affect the adhesion of the later organisms to the respiratory epithelium. Preliminary studies performed in our laboratory suggest that oral bacteria may modulate the adhesion of respiratory pathogens to epithelial cell lines. In addition, oral bacterial products or cytokines in oral/pharyngeal aspirates may stimulate cytokine production from respiratory epithelial cells, resulting in recruitment of inflammatory cells. The resulting inflamed epithelium may be more susceptible to respiratory infection. Further preliminary data are presented that some species of oral bacteria may induce the release of proinflammatory cytokines from epithelial cell lines to an extent similar to that seen for respiratory pathogens. Ann Periodontol 2001;6:78‐86.
Bidirectional Interrelationships Between Diabetes and Periodontal Diseases: An Epidemiologic Perspective
Authors: Taylor George W.
Published: February 2005

This review evaluates evidence for a bidirectional relationship between diabetes and periodontal diseases. A comprehensive Medline search of the post‐1960 English language literature was employed to identify primary research reports of relationships between diabetes and periodontal diseases. Reports included in the review on the adverse effects of diabetes on periodontal health (DM→PD) were restricted to those comparing periodontal health in subjects with and without diabetes. Review of adverse affects of periodontal infection on glycemic control included reports of periodontal treatment studies and follow‐up observational studies in which changes in glycemic control could be assessed. Observational studies reporting DM→PD provided consistent evidence of greater prevalence, severity, extent, or progression of at least one manifestation of periodontal diseases in the large majority of reports (supportive evidence in 44/48 total reviewed; 37/41 cross‐sectional and 7/7 cohort). Additionally, there were no studies reviewed with superior design features to refute this association. Treatment studies provided direct evidence to support periodontal infection having an adverse, yet modifiable, effect on glycemic control. However, not all investigations reported an improvement in glycemic control after periodontal treatment. Additional evidence to support the effect of severe periodontitis on increased risk for poorer glycemic control comes from 2 follow‐up observational studies. The evidence reviewed supports viewing the relationship between diabetes and periodontal diseases as bidirectional. Further rigorous, systematic study is warranted to establish that treating periodontal infections can be influential in contributing to glycemic control management and possibly to the reduction of the burden of complications of diabetes mellitus. Ann Periodontol 2001;6:99‐112.
Bioinformatics and Approaches to Identifying Polygenic Susceptibility Traits
Authors: Weir Bruce S.
Published: February 2005

The role of genetic factors in periodontal disease is now well recognized, although details for the genetic mechanisms of the disease and implications for therapy can be as obscure as they are for other human traits. This paper addresses the role that the analysis of genome‐wide data might play in helping to understand the molecular determinants of periodontal risk. Very few human diseases are not polygenic, in that an individual's susceptibility depends on his or her constitution at many genetic loci, each of which may have a small effect. Not only do these loci interact, but also their actions and interactions depend on nongenetic factors. Much of the statistical machinery to handle this complexity was developed in the plant and animal breeding context, where crosses between inbred lines selected for trait differences could be conducted. Human polygenic studies began with studies on large pedigrees, but have expanded to include case‐control analyses of random samples of individuals who differ in disease status, and studies of marker transmissions within nuclear families. In the area of characterizing the genetic architecture of complex traits, the relatively new field of bioinformatics is distinguished from the more mature fields of statistical genetics or genetic epidemiology by its focus on genome‐wide data. The very dense sets of genetic markers now available, particularly those at single nucleotide positions (SNPs), have meant that it is possible to seek linkages or associations between chromosomal position and disease from the whole genome in a single study. Apart from the obvious problems of scale, there are real issues involved with multiple testing and recognizing interactions. Current thinking tends to focus on relatively conserved “haplotype blocks” instead of single genetic markers, although there is no consensus on the utility of this emphasis. Ann Periodontol 2002;7:1‐7.
Interactions of Oral Pathogens With Toll‐Like Receptors: Possible Role in Atherosclerosis
Authors: Hajishengallis George , Sharma Ashu , Russell Michael W. , Genco Robert J.
Published: February 2005

Toll‐like receptors (TLR) function as important signal transducers that mediate innate immune and inflammatory responses to pathogens through pattern recognition of virulence molecules. Although TLRs mediate protection against infection, it is also likely that they may have a pathophysiologic role in certain inflammatory diseases, such as atherosclerosis. In atherosclerotic lesions, endothelial cells and macrophages have been shown to upregulate TLR expression and may respond to TLR agonists of microbial origin, resulting in detrimental inflammatory reactions. Some of these potential TLR‐activating virulence factors may be of oral origin. The detection in atherosclerotic plaques of DNA specific for Porphyromonas gingivalis and other periodontal pathogens suggests that these pathogens disseminate into the systemic circulation and localize in atheromas. The potential of periodontal and some other oral pathogens to activate TLRs in vivo is suggested by findings from cell culture experiments on interactions of selected virulence protein adhesins with TLRs and their coreceptors. Specifically, we have shown that proinflammatory cytokine induction by P. gingivalis fimbriae was inhibited by monoclonal antibodies to TLR2, TLR4, CD14, and β2 integrins, but not by immunoglobulin isotype controls. Cytokine induction by Bacteroides forsythus protein A depended heavily on CD14 and TLR2. We also found that the ability of Streptococcus mutans protein AgI/II to stimulate cytokine release was partially dependent on CD14 and TLR4. Moreover, P. gingivalis fimbriae induced TLR‐dependent activation of nuclear factor‐κB and upregulation of costimulatory molecules in monocytic cells. These proinflammatory activities have been implicated in the pathogenesis of periodontitis, and similar inflammatory mechanisms could potentially operate in atherosclerosis. Studies by other groups have shown that P. gingivalis is capable of stimulating low‐density lipoprotein oxidation, foam cell formation, and rupture of atherosclerotic plaque through induction of matrix metalloproteinases. Interestingly, at least some of these activities can be induced by TLR agonists (lipopolysaccharide and heat‐shock protein‐60) from Chlamydia pneumoniae, a major risk factor in atherosclerosis. Future research in animal models and in vitro cellular systems with defined mutations in TLRs may implicate TLR participation in oral pathogenmediated atherosclerotic processes, thereby providing a mechanistic basis for the epidemiological findings linking oral pathogens to atherosclerotic disease. Ann Periodontol 2002;7:72‐78.
Associations Between Periodontal Disease and Risk for Atherosclerosis, Cardiovascular Disease, and Stroke. A Systematic Review
Authors: Scannapieco Frank A. , Bush Renee B. , Paju Susanna
Published: February 2005

Background: Recent studies implicate exposure to systemic conditions involving chronic inflammation, including chronic periodontitis, in the etiology of atherosclerosis

Rationale: A systematic review of the literature was conducted to assess the association between chronic inflammatory periodontal disease and atherosclerosis.

Focused Question:Does periodontal disease influence the initiation/ progression of atherosclerosis and, therefore, cardiovascular disease (CVD), stroke, and peripheral vascular disease (PVD)?

Search Protocol: MEDLINE, pre‐MEDLINE, MEDLINE Daily Update, and the Cochrane Controlled Trials Register were searched to identify human studies that related variables associated with atherosclerosis to periodontal disease. Searches were made for papers published from 1966 through March 2002.

Inclusion criteria: Published randomized controlled clinical trials (RCTs), longitudinal, cohort, and case‐control studies were included. Study participants included those with atherosclerosis, myocardial infarction (MI), stroke, or PVD. Oral conditions included periodontal disease.

Exclusion criteria: Only studies on humans were included. Data Collection and Analysis: Because the studies used different oral assessment measures, it was not possible to perform a metaanalysis of the data reported. Weighted mean differences, relative risks, or odds ratios were compared for cohort studies.

Main Results

Of the initial 1,526 studies identified, 31 (including 8 case‐control and 18 cross‐sectional reports) were included in the analysis. Taken together, most of the literature supports a modest association between periodontal disease and atherosclerosis. However, data reported in several studies do not show this association.

The absence of a standard definition and measures for periodontal disease complicates interpretation of results, as do potential confounding risk factors common to both conditions.

Reviewers' Conclusions

Periodontal disease may be modestly associated with atherosclerosis, MI, and CVD.

Additional large‐scale longitudinal epidemiologic and intervention studies are necessary to validate this association and to determine causality.

Ann Periodontol 2003;8:38‐53.
Effective Laser Ablation of Bone Based on the Absorption Characteristics of Water and Proteins
Authors: Spencer Paulette , Payne John M. , Cobb Charles M. , Reinisch Lou , Peavy George M. , Drummer Dino D. , Suchman David L. , Swafford James R.
Published: February 2005

Background: Collateral thermal damage and residual char formation have severely limited the use of conventional lasers in the surgical preparation of bony tissue. Thermal damage from lasers can be minimized by selecting a wavelength that is strongly absorbed and by reducing the laser pulse duration. In contrast to the fixed wavelengths and microsecond pulse intervals of conventional lasers, the Vanderbilt free electron laser (FEL) can be set at wavelengths ranging from 2.1 to 9.8 μm, and the pulse duration can be reduced to a series of 1 to 2 picosecond (ps) micropulses delivered in succession over intervals of 4 microsecond macropulses. The purpose of this study was to compare the morphologic and chemical changes induced in the near‐surface region of bone following exposure to the FEL at 3.0, 6.1, and 6.45 μm wavelengths. The selected wavelengths coincide with the vibrational modes of proteins and water within bone.

Methods: Under general anesthesia, laser incisions were made in the tibias of 14 skeletally mature rabbits. Laser parameters included 22.5 ± 2.5 mJ/pulse delivered in individual 4 microsecond macropulses at a repetition rate of 30 Hz, focused to 200 μm and 500 μm spot sizes. Laser incisions were made using a computer‐assisted surgical program, and control incisions were created with a bone saw. Rabbits were euthanized after the final incision, tibias recovered, and non‐decalcified specimens processed for light microscopy. Separate samples were prepared for FTIR (Fourier transform infrared) photoacoustic spectroscopic analysis.

Results: The light microscopy sections of the ablation defects created at the differing wavelengths showed similar features, i.e., 2 zones of collateral damage, a zone generally <10mm of extensive thermal damage, and a wider zone of empty lacunae. In comparing treated and untreated surfaces, the spectral differences were limited to a relative decrease in intensity of the amide II and III absorption peaks in all laser‐treated surfaces.

Conclusions: Spectroscopic and histologic results indicated minimal thermal damage to bone ablated at 3.0, 6.1, and 6.45 μm wavelengths using the FEL (Fourier transform infrared) at the specified parameters. The FTIR photoacoustic spectroscopic results suggest that the char layer is limited to an area less than approximately 6 µm from the surface. J Periodontol 1999; 70: 68‐74.
Clinical Evaluation of the Treatment of Class II Furcation Involvements With Bioabsorbable Barriers Alone or Associated With Demineralized Freeze‐Dried Bone Allografts
Authors: De Leonardis D. , Garg A.K. , Pedrazzoli V. , Pecora G.E.
Published: February 2005

Background: Class II furcation lesions are a challenging scenario for periodontal therapy and a serious threat for tooth prognosis. Guided tissue regeneration represents a viable treatment option, but some aspects remain to be clarified as to the efficacy of bone substitutes used in GTR procedures. The clinical efficacy of demineralized freeze‐dried bone allografts (DFDBA) for regenerative procedures is presently under scrutiny.

Methods: This study evaluated the adjunctive clinical effects of DFDBA associated with a bioabsorbable (polylactic acid) barrier membrane in the regenerative treatment of human Class II furcation lesions as compared to the same type of barrier alone. Twelve patients with bilateral Class II furcation defects on lower first molars participated in the study. In each patient, one tooth was randomly assigned to treatment consisting of open surgical debridement followed by the placement of DFDBA (GTR+DFDBA, or test group) and a bioabsorbable barrier, while the contralateral side received the same flap surgery followed by use of the bioabsorbable membrane alone (GTR, or control group). The clinical efficacy of the 2 treatment modalities was evaluated at 6 and 12 months postoperatively. Measurements included vertical probing depth (VPD), horizontal probing depth (HPD), clinical attachment level (CAL), amount of gingival recession (GR), and change in class of clinically detectable furcation involvement (FC).

Results: Both treatments yielded significant improvements for all clinical parameters between baseline and 6 and 12 months (P<0.05). The comparison between test and control groups revealed significantly greater reduction in HPD (P=0.01) and higher values of GR (P=0.008) for the test group. The mean gain in HPD for test sites was 2.3 mm, while it amounted to 1.7 mm for controls. A significantly greater proportion of test sites could be classified postoperatively as Class I defects compared to controls (91% versus 50%, respectively).

Conclusions: The results of this study indicate that significant improvements from baseline occurred in VPD, HPD, CAL, and clinically detectable furcation involvement after the treatment of Class II furcation lesions with a bioabsorbable membrane with or without the adjunctive use of DFDBA. In addition, the placement of DFDBA in the furcation defect under the bioabsorbable membrane resulted in a greater mean reduction of horizontal probing depth when compared to the regenerative therapy alone. J Periodontol 1999; 70: 8‐12.
Spontaneous Repositioning of Pathologically Migrated Teeth
Authors: Gaumet Pierre E. , Brunsvold Michael I. , McMahan C. Alex
Published: February 2005

Background: There is limited clinical evidence that pathologically migrated teeth may reposition themselves after conventional periodontal treatment. The current research was carried out to determine the frequency of spontaneous repositioning of pathologically migrated teeth after routine periodontal therapy, and to study the relation between the severity of migration and the degree of repositioning following treatment.

Methods: Sixteen patients with moderate to severe periodontal disease and presenting 33 diastema sites secondary to pathologic migration participated in this study. After conventional periodontal treatment had been performed, reactive repositioning was assessed by measuring the space between pathologically migrated teeth and adjacent teeth on study models obtained at baseline, re‐evaluation at 6 weeks after scaling and root planing, and 4 months after surgery.

Results: After scaling and root planing only, 48.5% of all sites exhibited some degree of repositioning with 36.4% of all sites closing completely. After surgery (6 months after baseline observations), 69.7% of all sites exhibited some degree of repositioning with 51.5% of all sites closing completely. When only small to moderate diastemata were considered (<1 mm), 77.8% of sites closed completely.

Conclusions: The findings of this study support the hypothesis that spontaneous repositioning after conventional periodontal treatment is likely, particularly when only light to moderate degrees of pathologic migration are considered. We hypothesize that this spontaneous movement is due to wound contraction during healing. J Periodontol 1999;70:1177‐1184.
Qualitative Analysis of Peripheral Peri‐Implant Bone and Influence of Alendronate Sodium on Early Bone Regeneration
Authors: Meraw Stephen J. , Reeve Charles M.
Published: February 2005

Background: Alendronate sodium increases alveolar bone density with systemic use. It inhibits osteoclast activity and is thought to result in a net increase in osteoblastic activity. However, little is known about local in vivo use. The purpose of this study was to evaluate the effect of local delivery of alendronate on bone regeneration within peri‐implant defects. Peri‐implant bone was examined histomorphometrically to evaluate the amount of supporting bone peripheral to the bone‐implant interface.

Methods: Six adult hound dogs were evenly divided into 2 groups, with one group receiving alendronate‐coated dental implants and the other group serving as controls. Dental implants were placed immediately after extraction of right and left second, third, and fourth mandibular premolars. Forty‐eight dental implants were placed (2 types in each dog: 24 hydroxyapatite [HA]‐coated and 24 titanium machine‐polished [TMP]), for a total of 4 variables. A bioabsorbable collagen membrane was secured over the implants and defects, and the flaps closed primarily. The dogs were sacrificed on day 28. Specimens were sectioned, mounted, and stained with Stevenel's blue and van Gieson's picric fuchsin. The amount of bone adjacent and 1 mm peripheral to the implant surface was recorded with a computerized microscopic digitizer.

Results: Locally applied alendronate resulted in significantly increased amounts of bone (P <0.0002, ANOVA) in the peripheral area with both HA and TMP implants. However, the most influential factor in the amount of peripheral bone was the type of implant surface (P <0.0001).

Conclusions: Local application of alendronate is useful in increasing the amount of peripheral peri‐implant bone. Also, the amount of supporting bone was not related to the bone‐to‐implant contact but to the surface characteristics of the implant. The findings of the present study indicate that the evaluation of dental implant‐supporting bone should include peripheral bone as well as bone‐to‐implant interface. J Periodontol 1999;70:1228‐1233.
Culture of Gingival Fibroblasts on Bioabsorbable Regenerative Materials In Vitro
Authors: Simain‐Sato F. , Lahmouzi J. , Kalykakis G.K. , Heinen E. , Defresne M.P. , De Pauw M.C. , Grisar T. , Legros J. J. , Legrand R.
Published: February 2005

Background: The use of membranes in guided tissue regeneration (GTR) can limit the apical migration of gingival cells and favor the establishment of new attachment by periodontal ligament fibroblasts. However, gingival recession during healing following GTR has been described as a frequent complication. The purpose of this study was to determine if gingival fibroblasts are affected by the composition of the bioabsorbable membranes used in mucogingival surgery.

Methods: Two type of bioabsorbable regenerative materials were used as cell carriers. Wistar rat gingival fibroblasts (RGF) were obtained from attached gingiva, cut into small fragments, and placed in culture dishes. When confluent, cells were detached using trypsin and identified as “first transferred cells” (P1). At the third passage (P3), cell count, trypan blue exclusion test, acid phosphatase activity, DNA synthesis, phase contrast microscopy, and scanning electron microscopy were performed. The cells were then placed in wells containing the membranes and incubated for 72 hours.

Results: When examined under microscopy, the control wells (without membranes) showed one cell type with the elongated appearance characteristic of fibroblasts. The wells with membranes showed an altered cell morphology with a high proportion of cell fragments regardless of the type of membrane used.

Conclusions: These results suggest that cell carrier membranes could affect RGF morphology and thus alter gingival tissue healing following GTR. J Periodontol 1999;70:1234‐1239.
The Effect of Smoking and Periodontal Treatment on Salivary Composition in Patients With Established Periodontitis
Authors: Zuabi Otman , Machtei Eli E. , Ben‐Aryeh Hanna , Ardekian Leon , Peled Micha , Laufer Dov
Published: February 2005

Background: The purpose of this study was to evaluate the effect of smoking on the periodontal status and the salivary composition in subjects with established periodontitis before and after periodontal therapy.

Methods: Our study group included 26 healthy subjects, 12 smokers and 14 non‐smokers with established periodontitis. Clinical measurements and non‐stimulated whole saliva were obtained and analyzed at baseline and after scaling and root planing. Smokers presented at baseline with significantly greater probing depth (4.16 ± 0.26) compared to non‐smokers (3.52 ± 0.32) which was statistically significant (P = 0.0268); likewise, baseline clinical attachment level was greater in smokers (4.49 ± 0.31 compared to non‐smokers 3.87 ± 0.13; P = 0.0620). Mean plaque index was also greater in smokers compared to non‐smokers (0.86 and 0.65, respectively; P = 0.0834). Baseline pretreatment sodium values were significantly greater in non‐smokers (14.36 mEq/l compared to 9.31 mEq/l in smokers; P = 0.0662); likewise non‐smokers exhibited 50% greater salivary calcium levels (6.04 mg/100 ml compared to 4.32 mg/100 ml in smokers; P = 0.0133).

Results: Post‐treatment probing depth and clinical attachment level were not different between smokers and non‐smokers; this in spite of significant difference in plaque index in smokers (0.35 compared to 0.13 in non‐smokers; P = 0.0135). Post‐treatment, smokers had reduced calcium concentration (3.58 mg/100 ml compared to 5.11 mg/100 ml in non‐smokers; P = 0.0438). Treatment affected albumin level in smokers only, consequently non‐smokers had significantly greater salivary albumin concentration (1.1 mg/100 ml compared to 0.38 mg/100 ml in smokers; P = 0.0274).

Conclusions: Subjects with established periodontitis exhibited elevated concentrations of salivary electrolytes and proteins. Within this study group, smokers exhibited greater disease level but reduced sodium, calcium, and magnesium concentrations. Smokers responded favorably to treatment. The clinical improvement eliminated the differences in salivary composition. J Periodontol 1999;70:1240‐1246.
Comparison of Nd:YAG Laser Versus Scaling and Root Planing in Periodontal Therapy
Authors: Liu Cheing‐Meei , Hou Lein‐Tuan , Wong Man‐Ying , Lan Wan–Hong
Published: February 2005

Background: The Nd:YAG laser has recently been used in the treatment of periodontal disease. However, although a clinical reduction of probing depth and gingival inflammation to this new approach has been reported, it has not been fully evaluated. Interleukin‐1 beta (IL‐1β), a potent stimulator of bone resorption, has been identified in gingival crevicular fluid (GCF), which is closely associated with periodontal destruction. The aim of this study was to compare the effects of Nd:YAG laser treatment versus scaling/root planing (SRP) treatment on crevicular IL‐1β levels in 52 sampled sites obtained from 8 periodontitis patients

Methods: One or 2 periodontitis‐affected sites with a 4 to 6 mm probing depth and horizontal bone loss from 3 adjacent single‐root teeth in each of 4 separate quadrants were selected from patients for clinical documentation and IL‐1β assay. Sampling site(s) from each diseased quadrant was randomly assigned to one of the following groups: 1) subgingival laser treatment (20 pps, 150 mJ) only; 2) SRP only; 3) laser treatment first, followed by SRP 6 weeks later; or 4) SRP first, followed by laser therapy 6 weeks later. The GCF was collected and the amount of IL‐1β was assayed by enzyme‐linked immunosorbent assay (ELISA). Clinical parameters and GCF were measured at baseline and biweekly after therapy for 12 weeks.

Results: An obvious clinical improvement (marked decrease in the number of diseased sites with gingival index ≥2) and reduction of crevicular IL‐1β were found in all groups. The level of IL‐1β was significantly lower in the SRP group (P = 0.035) than in the laser therapy group for the duration of the 12 weeks. The laser combined SRP therapy group showed a further reduction of IL‐1β (6 to 12 weeks after treatment) than either laser therapy alone or SRP combined laser therapy.

Conclusions: Our data suggest that laser therapy appeared to be less effective than traditional SRP treatment. Of the 4 treatment modalities, inclusion of SRP was found to have a superior IL‐1β response, when compared to other therapies without it. In addition, no additional benefit was found when laser treatment was used secondary to traditional SRP therapy. J Periodontol 1999;70:1276‐1282.
Merits of Soft Nitriding Scalers
Authors: Fujimura Tetsuyuki , Nagai Atsushi , Kaneko Noriaki , Morishita Kouichiro , Ohta Norio , Kaya Hidehiro
Published: February 2005

Background: It has been demonstrated that nitriding modifies the physical characteristics of metals. The purpose of this study was to evaluate the changes induced by 3 levels of inexpensive soft nitriding treatments on commercial sickle scalers. Methods: Taglite scalers (NT) were soft nitrided for 30 (SN30), 60 (SN60), or 90 (SN90) minutes. The cumulated scaled material was weighed every 10 strokes × 10 and thereafter every 1,000 to 8,000 strokes by an automatic scaling apparatus against epoxy resin. Weight differences were used to indicate abrasion resistance; the relative efficiency (RE) was calculated as the ratio of scaled amount at a given number of strokes (SN/NT). The hardness and the tensile strengths were determined for each soft nitriding treatment level. The nitrided layer thickness of representative SN scalers was observed by electron probe x‐ray microanalysis.

Results: The SN60 was not significantly different from SN30 or SN90, but the SN90 was more efficient than SN30 for the first 100 strokes (P <0.01). The RE of all SN scalers was significantly greater (2.3 to 2.7 times) than the NT scalers from the beginning of the study and throughout all time periods (SN90> SN60 > SN30); it increased further during the first 100 strokes (9.7 to 15.5 times), indicating the NT scalers wore out faster than SN scalers. The untreated scalers' performance decreased to 10% of baseline after 100 strokes; but even after 1,000 strokes, the SN60 and SN90 performed better than new untreated scalers. Thereafter, all scalers' performance, including SN scalers, decreased. While the NT blades ceased to cut measurable amounts after 7,000 to 8,000 strokes, all SN scalers continued to cut. Although SN90 scalers had the thickest soft layer and were the hardest (P <0.01), the SN60 had the highest tensile strength (P <0.01), suggesting that it might be the safest in practice.

Conclusions: Sixty minutes of soft nitriding treatment of commercially available taglite scalers seem to be the optimal treatment duration to increase their durability, on the order of 100 to 1,000 times, without jeopardizing safety for clinical use. J Periodontol 1999;70:1339‐1344.
Growth Factors Regulate Expression of Osteoblast‐Associated Genes
Authors: Strayhorn Christopher L. , Garrett J. Stephen , Dunn Richard L. , Benedict James J. , Somerman Martha J.
Published: February 2005

Background: The goal of periodontal regenerative therapies is to reconstruct periodontal tissues such as bone, cementum, and periodontal ligament cells (PDL). The need to establish predictable treatment modalities is important for reconstruction of these tissues. The aim of this study was to determine the effects of a low molecular extract of bovine bone protein (BP) containing bone morphogenetic proteins (BMPs) 2, 3, 4, 6, 7, 12, and 13, alone or in combination with platelet‐derived growth factor (PDGF) and/or insulin‐like growth factor (IGF) on osteoblast differentiation in vitro.

Methods: BP, mixed with a collagen matrix, was added to a poly (DL‐lactide‐co‐glycolide) polymer (PLG) and placed at orthotopic sites in the skullcaps of Sprague‐Dawleys rats. At day 28, rats were sacrificed for histological analysis. All sites treated with the polymer/BP produced bone while control sites (without BP) showed no bone formation. Having established the biological activity of BP, in vitro studies were initiated using MC3T3‐E1 cells, a mouse osteoprogenitor cell line. The ability of BP and other growth factors to alter cell proliferation was determined by Coulter counter, and differentiation was determined by Northern analysis for specific genes.

Results: When compared with cells treated with 2% serum alone, PDGF enhanced cell numbers at 10 and 20 ng/ml; IGF produced no significant effect at these doses; and BP at 10 and 20 µg/ml decreased cell proliferation. Northern analysis revealed that PDGF blocked gene expression of osteopontin (OPN) and osteocalcin (OCN), while BP and IGF promoted gene expression of bone sialoprotein (BSP) and OPN. The combination of BP and IGF enhanced expression of OPN beyond that of either BP or IGF alone. PDGF was able to block the effects of IGF on gene expression, but not those of BP.

Conclusions: These results indicate that BP, PDGF, and IGF influence cell activity differently, and thus raise the possibility that combining factors may enhance the biological activity of cells. J Periodontol 1999;70:1345‐1354
Immunohistologic and Morphometric Analysis of Cytotoxic T Lymphocytes in Gingivitis
Authors: Séguier Sylvie , Godeau Gaston , Leborgne Michelle , Pivert Gérard , Brousse Nicole
Published: February 2005

Background: Gingivitis is an inflammatory phenomenon localized in gingival tissues and histologically characterized by an infiltration of several inflammatory cell populations. The purpose of this study was to characterize, localize, and quantify in situ inflammatory and cytotoxic T lymphocytes using immunolabeled gingival tissue sections in order to specify their implication during human gingivitis, since it is well known that such cells play an important role in the defense against bacterial elements.

Methods: Paraffin gingival tissue sections from 7 patients with gingivitis (G) and from 7 clinically and histologically healthy controls (C) were immunohistochemically stained by specific antibodies (anti‐CD45, anti‐CD3, anti‐CD8, anti‐CD20, anti‐TIA‐1, anti‐GrB, and anti‐CD68), allowing the quantification of inflammatory cells in upper gingival epithelium (Ep), in the basal epithelium layer (BEp), and in upper connective tissue (CT). Collagen fibers were stained by sirius red F3Ba in order to evaluate, by morphometric and automated image analysis, the surface occupied by collagen bundles and to histologically confirm the absence of pathology of the clinically selected healthy controls.

Results: In the gingivitis group, CD45+, CD3+, CD8+, TIA‐1+, and GrB+ lymphocyte numbers were significantly increased in Ep (P <0.05); and CD45+, CD3+, and TIA‐1+ lymphocyte numbers were significantly increased in BEp (P <0.05) compared respectively to Ep and BEp of group C. In Ep of group G, mean CD8+/CD3+ cell ratio was significantly increased (P <0.05) compared to BEp and CT, and 25% of TIA‐1+ cytotoxic cells were activated GrB+ cells.

Conclusions: The present study suggests that intraepithelial cytotoxic T lymphocytes play an important role during gingivitis and CD8 expression and that activation of TIA‐1+ cytotoxic cells could be induced in Ep in response to epithelial environment. Thus, gingival epithelial tissue, which is generally only considered as a physical barrier, in fact contains numerous immune cell populations preventing the infiltration of pathogenic elements into the connective tissue. Particular clinical attention must be taken for the preservation of the epithelial tissue integrity. J Periodontol 1999;70:1383‐1391.
Periodontal Plastic Surgery in a Dystrophic Epidermolysis Bullosa Patient: Review and Case Report
Authors: Brain Jeffrey H. , Paul Brian F. , Assad Daniel A.
Published: February 2005

Epidermolysis bullosa (EB) is a group of genetic disorders in which patients frequently present with fragile skin and mucosal surfaces that blister following minor trauma; 23 subtypes have been recognized, but their precise pathogenesis and etiology remain obscure. There is no treatment for EB, only palliative therapy. Oral bullae are the most common oral finding and affect all surfaces. Patients with EB present a unique challenge in terms of periodontal therapy. The following article reviews this disorder and describes the complications encountered when providing periodontal plastic surgery to a patient exhibiting this condition. A 36‐year‐old female with dystrophic EB presented for treatment of a 3 mm recession area with minimal attached gingiva on the facial of #24 and 25. Oral evaluation revealed multiple ulcers. The treatment consisted of a subepithelial connective tissue graft in conjunction with a coronally positioned flap and buccal frenectomy. Most of the epithelium associated with the surgical area and buccal vestibule sloughed. During the postoperative course, the frenum had regenerated at a more coronal level and was applying tension on the gingival tissues. It appeared that a connective tissue union had formed between the de‐epithelialized surface of the facial flap and the buccal mucosa of the vestibule. A second frenectomy was performed, and a clear acrylic stent was fabricated to prevent the union of the connective tissue of the facial flap to the buccal mucosa. The stent prevented the fusion of both connective tissue layers and allowed time for epithelium migration. J Periodontol 1999;70:1392‐1396.