Abstracts - Periodontics
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Generalized cervical root resorption associated with periodontal disease
1. A patient-based assessment of implant-stabilized and conventional
complete dentures
2. Freestanding and multiunit immediate loading of the expandable implant:
An up-to-40-month prospective survival study
3. Link may exist between passive smoking and Periodontal Disease,
4 Interleukin-8 and Intercellular Adhesion Molecule 1 Regulation in Oral
Epithelial Cells by Selected Periodontal Bacteria: Multiple Effects of Porphyromonas
gingivalis via Antagonistic Mechanisms
5 Continuous and intermittent bone distraction using a microhydraulic cylinder:
an experimental study in minipigs - British Journal of Oral & Maxillofacial Surgery
6 Study links periodontal health with obstructive pulmonary disease - ADA News
7 Tissue differentiation and cytokine synthesis during strain-related
bone formation in distraction osteogenesis - British Journal of Oral & Maxillofacial Surgery
1. A patient-based assessment of implant-stabilized and conventional
complete dentures - Journal of Prosthetic Dentistry
P. Finbarr Allen, BDS, PhD, MSca
Anne S. McMillan, BDS, PhDb
David Walshaw, BSc, PhD, MScc
The Dental School, University of Newcastle upon Tyne, United Kingdom,
and Faculty of Dentistry, University of Hong Kong, Hong Kong
Abstract
Statement of problem. Outcomes of oral implant therapy have been described primarily in terms
of implant survival rates and the durability of implant superstructures. Reports of
patient-based outcomes of implant therapy have been sparse, and none of these studies
have used oral-specific health status measures.
Purpose. This study assessed the impact of implant-stabilized prostheses on the health
status of complete denture wearers using patient-based, oral-specific health status measures.
It also assessed the influence of preoperative expectations on outcome.
Material and methods. Three experimental groups requesting replacement of their conventional
complete dentures completed an Oral Health Impact Profile (OHIP) and a validated denture
satisfaction scale before treatment. One group received an implant-stabilized
prosthesis (IG), and 2 groups received new conventional complete dentures (CDG1 and CDG2).
After treatment, all subjects completed the health status measures again; preoperative
data were compared with postoperative data.
Results. Before treatment, satisfaction with complete dentures was low in all 3 groups.
Subjects requesting implants (IG and CDG1) had high expectations for implant-stabilized
prostheses. Improvement in denture satisfaction and OHIP scores was reported by all
3 groups after treatment. Subjects who received their preferred treatment (
IG and CDG2 subjects) reported a much greater improvement than CDG1 subjects.
Preoperative expectation levels did not appear to influence satisfaction with the
outcomes of implant therapy in IG subjects.
Conclusion. Subjects who received implants (IG) that replaced conventional complete
dentures reported significant improvement after treatment, as did subjects who requested
conventional replacement dentures (CDG2). The OHIP appears useful in identifying patients
likely to benefit from implant-stabilized prostheses. (J Prosthet Dent 2001;85:141-7.)
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2. Freestanding and multiunit immediate loading of the expandable implant:
An up-to-40-month prospective survival study - Journal of Prosthetic Dentistry
Freestanding and multiunit immediate loading of the expandable implant:
An up-to-40-month prospective survival study
Hwan Young Jo, DDS, MSD, PhDa
Peter K. Hobo, DDSb
Sumiya Hobo, DDS, MSD, PhDc
Seoul Dental Institute, Seoul, Korea, and International Dental Academy, Tokyo, Japan
Abstract
Statement of problem. The subject of immediate loading of dental implants has received
substantial attention, although it appears to conflict with the basic principles of
dental implant therapies developed and established over the past 20 years. Clinicians
would welcome the use of a reliable, immediate-loading implant system.
Purpose. The purpose of this study was to evaluate the effectiveness of an expandable
implant design for immediate and delayed loading and for freestanding and multiunit
situations.
Material and methods. Two hundred eighty-six immediate-load Sargon implants were
placed in 75 patients during a 40-month period. Of the 273 implants that survived,
81 were placed into fresh extraction sockets and immediately loaded, 162 were placed
into healed sites and immediately loaded, and 30 were delay loaded. Some implants that
had failed to remain stable after immediate loading became stable and osseointegrated
after the load was removed and their expansion mechanisms were reactivated.
Results. The overall survival rate during the 40-month period was 96.0% in the maxilla
and 94.8% in the mandible. Implants placed in fresh extraction sockets showed a
98.9% survival rate. Healed sites showed a 93.9% survival rate. Immediate loading
of 52 fresh extraction socket implants in the maxilla showed a 100% survival rate
during the evaluation period.
Conclusion. Within the limitations of this study, it was shown that the feature of
mechanical expandability may provide operators some control over implant stability
during the vulnerable period after immediate loading of single, freestanding implants. (
J Prosthet Dent 2001;85:148-55.)
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3. Link may exist between passive smoking and Periodontal Disease,
Researchers Say - ScienceDaily
Source: University Of North Carolina At Chapel Hill (http://www.unc.edu/)
Date: Posted 2/16/2001
Link May Exist Between Passive Smoking And Periodontal Disease, Researchers Say
Chapel Hill -- Among U.S. residents who have never used tobacco products, those exposed
regularly to environmental tobacco smoke are more likely to develop gum disease than
others not exposed to such second-hand smoke, a new University of North Carolina at
Chapel Hill study suggests.
The study, which involved analyzing data from the Third National Health and Nutrition
Examination Survey from 1988 to 1994, or NHANES III, revealed between a 50 percent
and 60 percent increased risk of periodontal disease among non-smokers who are around
smokers than those who are not.
Researchers, who are affiliated with the UNC School of Dentistry, said their findings
provide evidence of an association but do not prove it.
A report on the research appears in the February issue of the American Journal of
Public Health. Authors are Drs. Samuel J. Arbes Jr. and Helga Agustsdottir, former
postdoctoral fellows with the Center for Oral and Systemic Diseases,
and Dr. Gary D. Slade, associate professor of dental ecology. "We found that among
adults in the United States who had never smoked cigarettes, 11 percent of those
exposed to environmental tobacco smoke in their homes or at work had periodontal
disease, and their risk was about 1.5 times higher than for people not exposed,"
Arbes said. "Even though this increase in risk is much smaller than the increase
in risk associated with active cigarette smoking - up to five times greater -
environmental tobacco smoke could account for many cases of gum disease nationwide."
Researchers evaluated NHANES III data on a subset of 6,611 U.S. residents age 18
and older who had never smoked or used other forms of tobacco. The survey is the
most recent in a series of national surveys conducted by the federal government
to help assess the health in this country. "One advantage to using the NHANES III
data is that it is a sample of the total civilian, non-institutionalized population
of the nation," Arbes said. "Therefore, our results can be generalized to the
U.S. population."
About a third of non-smoking adults in the study were exposed to environmental
tobacco smoke, which also is called "passive smoking," at home or at work, he said.
Investigators did not measure the amount.
How could the smoke cause gum disease? "Active smoking is one of the most important,
if not the most important, risk factor for periodontal disease, and many studies
have examined its effects," Arbes said. "One of the many chemicals that gets into
the body when a person actively smokes or breathes someone else's smoke is nicotine.
"Earlier studies have suggested that nicotine in cigarette smoke impairs the immune
system and causes blood vessels to constrict, including blood vessels in the tissues
around the teeth. This causes a decrease in oxygen in these tissues which, along with
an impaired immune system response, creates a favorable environment for bacteria that
cause periodontal disease."
Undoubtedly, the real picture is much more complicated, and the mechanism by which other
people's smoke may promote the illness has not been studied, he said. Periodontitis
destroys soft tissues and bone that support the teeth, which often leads to tooth loss.
"We strongly believe that it is premature to claim that passive smoking causes periodontal
disease or to make any policy recommendations," Arbes said. "However, we do feel that it is
reasonable to use these findings to repeat the known oral health hazards of active tobacco
consumption. We also hope the findings further motivate dental health providers to promote
tobacco cessation in their practices."
The National Institute of Dental and Craniofacial Research supported the study.
http://www.sciencedaily.com
4 Interleukin-8 and Intercellular Adhesion Molecule 1 Regulation in Oral Epithelial
Cells by Selected Periodontal Bacteria: Multiple Effects of Porphyromonas
gingivalis via Antagonistic Mechanisms
*** George T.-J. Huang,1,2,3,* Daniel Kim,1 Jonathan K.-H. Lee,1 Howard K. Kuramitsu,4 and
Susan Kinder Haake2,3,5 Section of Endodontics1 and Section of Periodontics,
5 Division of Associated Clinical Specialities, Division of Oral Biology and Medicine
and Orofacial Pain, 2 and Dental and Craniofacial Research Institute,3 UCLA School of
Dentistry, Los Angeles, California, and Department of Oral Biology and Microbiology,
SUNY Buffalo School of Dental Medicine, Buffalo, New York4
Received 15 August 2000/Returned for modification 13 October 2000/Accepted 21 November 2000
Interaction of bacteria with mucosal surfaces can modulate the production of proinflammatory
cytokines and adhesion molecules produced by epithelial cells. Previously, we showed that
expression of interleukin-8 (IL-8) and intercellular adhesion molecule 1 (ICAM-1) by gingival
epithelial cells increases following interaction with several putative periodontal pathogens.
In contrast, expression of IL-8 and ICAM-1 is reduced after Porphyromonas gingivalis
ATCC 33277 challenge. In the present study, we investigated the mechanisms that govern the
regulation of these two molecules in bacterially infected gingival epithelial cells.
Experimental approaches included bacterial stimulation of gingival epithelial cells by
either a brief challenge (1.5 to 2 h) or a continuous coculture throughout the incubation
period. The kinetics of IL-8 and ICAM-1 expression following brief challenge were such that
(i) secretion of IL-8 by gingival epithelial cells reached its peak 2 h following
Fusobacterium nucleatum infection whereas it rapidly decreased within 2 h after P. gingivalis
infection and remained decreased up to 30 h and (ii) IL-8 and ICAM-1 mRNA levels were
up-regulated rapidly 2 to 4 h postinfection and then decreased to basal levels 8 to 20 h
after infection with either Actinobacillus actinomycetemcomitans, F. nucleatum, or
P. gingivalis. Attenuation of IL-8 secretion was facilitated by adherent P. gingivalis strains.
The IL-8 secreted from epithelial cells after F. nucleatum stimulation could be down-regulated
by subsequent infection with P. gingivalis or its culture supernatant. Although these results
suggested that IL-8 attenuation at the protein level might be associated with P. gingivalis
proteases, the Arg- and Lys-gingipain proteases did not appear to be solely responsible
for IL-8 attenuation. In addition, while P. gingivalis up-regulated IL-8 mRNA expression,
this effect was overridden when the bacteria were continuously cocultured with the epithelial
cells. The IL-8 mRNA levels in epithelial cells following sequential challenge
with P. gingivalis and F. nucleatum and vice versa were approximately identical and were
lower than those following F. nucleatum challenge alone and higher than control levels or
those following P. gingivalis challenge alone. Thus, together with the protease effect,
P. gingivalis possesses a powerful strategy to ensure the down-regulation of IL-8 and ICAM-1.
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* Corresponding author. Mailing address: Division of Associated Clinical Specialties,
Section of Endodontics, 23-087 CHS, UCLA School of Dentistry, 10833 Le Conte Ave.,
Los Angeles, CA 90095-1668.
Phone: (310) 206-2691. Fax: (310) 794-4900. E-mail: gtjhuang@ucla.edu.
5 Continuous and intermittent bone distraction using a microhydraulic cylinder:
an experimental study in minipigs
J. Wiltfang, P. Keßler, H. -A. Merten, F. W. Neukam
p 2-7, Volume 39, Number 1, February 2001
Abstract
Distraction osteogenesis of the mandible is an option in the treatment of mandibular
hypoplasia. Today, only intermittent distraction devices are available for clinical
application. The aim of this study in minipigs was to evaluate continuous bone distraction
using a microhydraulic cylinder. After a seven-day interval, continuous or intermittent
distraction of 1.5mm/day was established for 10 days. Immediately after active distraction,
two animals and 20 days later the other four animals were killed and radiographs taken.
The mandible was then removed en bloc and the distracted bone examined histologically.
Inter mittent distraction forces of up to 2500kPa were necessary to move the cylinders'
piston. The pressure needed for continuous distraction was considerably lower (1200-1300kPa).
While the specific histological structure of the varying zones in the distraction gap
was similar after continuous and intermittent distraction, bone healing was accelerated
after continuous distraction as shown by ultrasonography and scanning elec tron microscopy.
Copyright 2001 The British Association of Oral and Maxillofacial Surgeons
Today's News Feb. 15, 2001
6 Study links periodontal health with obstructive pulmonary disease
Adding to the list of health problems associated with poor periodontal health, new research
findings link periodontal disease to increased risk for the respiratory disorder chronic
obstructive pulmonary disease, the sixth leading cause of death in the United States.
The results of a study of periodontal and respiratory health analyzing the connection
between chronic obstructive pulmonary disease (COPD) and periodontal disease are published
in the January issue of the Journal of Periodontology.
For the study, the oral health status of the research subjects was assessed from a summary
of cumulative caries experience, gingival bleeding, gingival recession, gingival probing
depth and periodontal attachment level.
Subjects with periodontal disease, defined by mean periodontal attachment loss of greater
than 3 millimeters, were found to have nearly a one-and-a-half times greater risk of COPD.
A distinct trend also was noted in that lung function seemed to diminish with increased
periodontal attachment loss, suggesting that periodontal disease activity may promote the
progression of COPD.
"Identification of potential risk factors that contribute to the development of chronic
bronchitis or emphysema - respiratory diseases that comprise COPD - may suggest
nterventions that could prevent or delay the onset of the disease, or slow its progression,
" the researchers concluded.
SOURCE: American Academy of Periodontology news release, 1/30/01.
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Document address:
http://www.ada.org
7 Tissue differentiation and cytokine synthesis during strain-related bone formation in
distraction osteogenesis
U. Meyer, T. Meyer, W. Schlegel, H. Scholz, U. Joos
p 22-29, Volume 39, Number 1, February 2001
Abstract
To investigate the contributions of various cytokines that are involved in mechanically
related bone formation, we applied defined uniaxial strains in a rabbit model of mandibular
elongation and examined the regenerating bone during early stages of dist raction osteogenesis
by histomorphometry. We also measured serum concentrations of various cytokines during the
distraction.
Cell proliferation and differentiation indices correlated significantly (P<0.001) with the
extent of load application. Serum concentrations of insulin-like growth factor-1 (IGF-1)
decreased after osteotomy whereas transforming growth factor [beta]1 (TGF[beta]1) showed
a postoperative increase. Prostaglandin E2 (PGE2) concentrations were constant throughout
the experimental period. Collagen degradation decreased slightly postoperatively and
increased in samples exposed to higher magnitudes of strain. Our data show that it is
the magnitude of mechanical strain that decides tissue response by a characteristic cell
proliferation and differentiation. The operative trauma leads to inverse changes in serum
concentrations of TGF[beta]1 and IGF-1, thereby promoting the recruitment of osteoblastic
precursor cells as well as collagen matrix synthesis. Copyright 2001 The British Association
of Oral and Maxillofacial Surgeons
