E-newsletter Vol - I
Number- X II May 2007
Laughter - The best
Part I - Dr. Vinayak Joshi
5 Reasons You Should
Be More Organized - Cathy Warschaw
Getting down to Roots
of Dentistry - News Article
............. : Dr. Rasha Seragelden
Laser Dentistry - A
basic Comparison between Er:YAG and Er,Cr:YSGG - Dr. Maziar Mir
the efficacy of a collagen GBR membrane (BioMend Extend) supported
by autogenous bone grafts, for the
treatment of peri-implant bony defects, during implant
We are one year old now! Dental follicle completes its first year
with this issue . In this edition I have published some of the
selected articles of the previous issues. In this edition we have
acknowledged some of our well wishers without whom we could not have
completed our first year.
in the year 2004
www.DentistryUnited.com was launched as a platform for gaining
and sharing knowledge. In 2006 we launched
"Dental Follicle" , our monthly E-newsletter , which now reached the
mail boxes of more than 30,000 dentists across the globe. We thank
you for your support.
I would like to thank a few special people without whose support
dental Follicle would not have been possible -
Our advertisers Rolence enterprises Taiwan . The company who makes
world class products for dentists . Rolence Enterprises- Taiwan
specializes in making dental equipments including Curing light ,
Curing light meter , Intra oral camera, Bleaching systems ,
Ultrasonic scaler , Ultrasonic cleaner ,Air turbine handpiece ,
Dental burs , Parts of dental unit and Disposable items. so next
time you see ROLENCE in any conference , remember you first saw it
on DentistryUnited and
Our techinical support Mr. Khalid Jaffar Syed who
holds an Engineering degree in computer science. Presently a part
time free lancer , providing IT services and solutions on .NET ,
J2EE and Oracle.An expert in Website design and support . He can be
Some of our other advertisers including One of
India's Leadng dental Implant supplier .For enquiries call
Mr.Promeet Nanda on - +91-98231-79349+91-98231-79349
A young Dentist had just started his own Clinic. He rented a
beautiful office and had it furnished with antiques. Sitting there,
he saw a man come into the front office. Wishing to appear the "busy
dentist", the gentleman picked up the phone and started to pretend
he had to give an appointment.
Finally he hung up and asked the visitor, "Can I help you?"
The man said, "Yeah, I've come to activate your phone lines."
C-reactive protein— Part I
The very first response of living
cells to injury or a noxious stimulus, anywhere in human body is
inflammation. The inflammation is then followed by secrection of
cytokines, mostly interlukines IL-1, IL-6, IL-8 and TNFα. The liver
responds by means of releasing acute phase reactants. One of the
most sensitive markers among the acute phase proteins is the
C-reactive protein. Other acute phase proteins are proteinase
inhibitors, coagulation factors, complement factors, transport
proteins and miscellaneous proteins like the serum amyloid A
C-reactive protein (CRP) derived
its name from its ability to precipitate the somatic
C-polysaccharide of Streptococcus pneumoniae. It is a member of the
family of proteins. CRP was originally discovered by Tillett and
Francis in 1930 as a substance in the serum of patients with acute
The CRP gene is located on the first
(1q21-q23). Human CRP is a calcium-dependent ligand binding protein,
which binds with highest affinity to phosphocholine (PC) residues,
as well as a variety of other autologous and extrinsic ligands, and
aggregates or precipitates the cellular, particulate or molecular
structures bearing these ligands.
In a healthy individual, the median
concentration of CRP is 0.8mg/l, but following a stimulus it could
rapidly increase by as much as 10,000 fold, with de novo hepatic
synthesis, serum concentrations beginning to rise by about 6h, and
peaking around 48h. The CRP levels also vary in relation to age and
sex (females having slightly higher concentration). CRP levels
accurately reflect the ongoing inflammatory process than any other
biochemical parameters, in most if not all diseases. The CRP value
is thus a very useful non-specific biochemical marker of
inflammation, measurement of which contributes importantly to: (i)
screening for organic disease; (ii) monitoring the response to
treatment of inflammation and infection; and (iii) detecting
intercurrent infection in the few specific diseases characterized by
modest or absent acute-phase responses to those diseases themselves.
CRP is a member of the class of
acute phase reactants as its levels rise dramatically during
processes occurring in the body. It is thought to assist in
binding to foreign and damaged cells and affect the
response to disease. It is also believed to play an important role
in innate immunity, as an early defense system against infections.
CRP is also thought to stimulate tissue factor production.
CRP measurements are used to asses
the active inflammation in sepsis or arthritis. High sensitive
methods which allow detection of low level states of inflammation
are important in CVD risk.
following types of CRP assays have been cleared: byU.S.
Department of Health and Human Services Food and Drug Administration
Conventional C-Reactive Protein
High sensitivity CRP (hsCRP)
Cardiac C-Reactive Protein (cCRP)
The American Heart Association
(AHA) has set a parameter for what is considered as normal hsCRP
If hs-CRP level is lower than 1.0
mg/L, a person has a low risk of developing cardiovascular
If hs-CRP is between 1.0 and 3.0
mg/L, a person has an average risk.
If hs-CRP is higher than 3.0
mg/L, a person is at high risk.
after repeated testing, patients have persistently unexplained,
markedly elevated hs-CRP (greater than 10.0 mg/L), other evaluation
should be considered to exclude noncardiovascular causes.
getting ones CRP level measured this is what AHA has to say:
person’s cardiovascular risk score — judged by global
risk assessment — is low (the possibility of developing
cardiovascular disease is less than 10 percent in 10 years, no test
is immediately warranted. If the risk score is in the intermediate
range (10-20 percent in 10 years), such a test can help predict a
cardiovascular and stroke event and help direct further evaluation
and therapy. However, the benefits of such therapy based on this
strategy remain uncertain. A person with a high risk score (greater
than 20 percent in 10 years) or established heart disease or stroke
should be treated intensively regardless of hs-CRP levels.”
next post will discuss about the various disease and in specific
relation of CRP to cardio vascular disease)
…..So understood by:
Dr Vinayak M. Joshi M.D.S ( perio)
Vol 1 , issue 3, August- 2006)
5 Reasons You Should Be More
by- Cathy Warschaw
Some people think being organized requires a
lot of work or maybe a complete system where you have to do a
complicated set of tasks. In short, many people view being organized
as impossible to achieve. While that is not really true, it takes a
disciplined person not to resort back to his/her old habits. It’s
really easy to do and you get many benefits when you’re organized.
Here are some of them.
1. You will have more room.
Being organized will provide you additional
“uncluttered” space. You won’t need to necessarily throw anything
out, you just need to place things in some sort of order and
maintain that order at all times.
2. You will be able to save time.
Looking for files at work? It’s organized
alphabetically in the cabinet. Being organized lets you look for
files that you might need in a hurry in the future. Looking for your
book? It’s safely stashed behind your bed. This is a really good
time-saving technique which would help you when you’re in a hurry.
3. You will also save money.
You don’t believe that? Try thinking why you
bought another ballpoint pen today? Isn’t it because you lost your
old one? Or think of the countless items you bought because you
thought you didn't have one of them at your house. Just think of how
much you could save in a year just by being organized.
4. You will feel more in control.
Did you know that clutter around your house and
at work causes the stress you’re feeling from time to time? It’s no
wonder you’re feeling more irritated at work. As your clutter goes,
you’ll feel that it is easier to breathe and take charge of your own
5. You will make a great impression to
This should be a good enough reason why you
should make a considerable effort to be organized. Just think of
your employer or office manager not pestering you to clean your work
area again. Or just think how you’ll never forget that you have a
Being organized requires a lot of discipline to
maintain. Nobody ever said it was easy. You need to make sure you
don’t lapse back to your old habits or all of what you have done
will be for nothing.
Warschaw is the Director of the Warschaw Learning Institute an
online educational site offering; Dental Office Management Program,
Telephone Training, HIPAA and various e-books. For more
information go to
www.WarschawLearningInstitute.com or call (323) 822-0917(323) 822-0917
(Above article originaly published in Vol 1 , Number 5 , October
down to Roots of Dentistry
Egypt has been a land of contribution to the human civilization from
365 days calender to massive public projetcs and now evidence
suggets the Roots of dentistry to be in Egypt.Archelologisits have
found the tombs of three dentists
The pictorial letters
also spell out the names of the chief dentist —
"Iy Mry, and assistants Kem Msw and Sekhem Ka Hawass"in
SAQQARA, Egypt. The tombs were Curse protected for
4,200-years--warngin :"Violate these tombs and you will be eaten by
a crocodile and a snake".
Their location near
the Step Pyramid of King Djoser — believed to be Egypt's oldest
pyramid — indicate the respect accorded dentists by Egypt's ancient
kings, who "cared about the treatment of their teeth,"
1 , Number 6 , November 2006 )
RASHA RECOMMENDS ............. :
The Issue of december 2006 was
very special as Dr.Rasha Seragelden joined us with her
recommendations! No doubt this young lady created a place for
herself by giving some of the best links in the next few issues
to come. I believe she is a "the intelligent , smart ,
resourseful dentist " to all the dentists who use internet to
gain information and knowledge. Below is my write-up on her
entry into the family of "Dental Follicle" and her first set of
With This Issue we have a
New person to provide you more information! I am sure if you are
a member of any Dentistry related group you might have come
across a person who sends maximum messages in the form of links!
Links , that are better than just good! Some links this Lady
sends have been appreciated by many members across various
I am sure you have guessed the person , its Dr.RASHA
happy to introduce a new feature on Dental Follicle , RASHA
RECOMMENDS! Where you will find the Links specific to specialty
are recommended by Dr.Rasha Seragelden!In case you are looking
for some information on a specific topic/case , just mail
us at Dentalfollicle@gmail.com
and Dr.Rasha Seragelden will find it for you , which will be
included in the next edition of Dental Follicle! ----
Dentistry - A basic Comparison between Er:YAG and Er,Cr:YSGG
DDS, MSc, PhD
ZPP, RWTH Hospital, Aachen, Germany
When the Hibst and Keller have published the first articles about
the ablation of tooth with Er:YAG laser on 1989 in English journals
(some years after German versions), nobody was estimating that in 8
years the speed of cut (Volume of ablation) could be practically
suitable for dental daily needs. On that time the 4-6 pulses per
second were recommended and the laser was cutting the tooth very
slowly. On 1995, the number of pulses increased to 20 and Er,Cr:YSGG
was also introduced to American dental society on 1997. At the same
year both wave lengths were successfully cleared with FDA and
delivered to dental clinics to be used
as an adjacent to drills!
On 2000, the discussions about the basics of mechanisms were hottest
topic of dental congresses and WATER role was under the focus of
investigators. On 2002 a basic study started by the author in Aachen
RWTH Hospital following the advance advises of Prof.Dr. Norbert
Gutknecht and guidances of Dr. Leon Vanweersch, Dr. Joerg Meister
and Dr. Rene Franzen.
The project was done with the help of two HIGH TECH cameras. First
one was able to make up to 40500 pictures per second. So, as is seen
in Figure-1, the author was able to monitor any pulse (with a length
of 140-180 microseconds) with looking at about 30 pictures.
Therefore, the accurate interactions between laser light, water and
enamel were accurately visualized.
Both wave lengths of 2780 nm (Er,Cr:YSGG) and 2940 nm (Er:YAG) were
irradiated in a distance of 1 mm in front to the enamel surface. The
water selected as the media between laser tip and tooth. By this
method, the different phases of any pulse interactions with first
micrometers of water layer at the start of pulse were reported.
There was no difference seen between two wave lengths not only at
start of pulse, but also in the rest of procedures.
The most important finding is that the basics of ablation with both
wave lengths are more and less the same and the important characters
of both in increasing the speed of cut would be the duration of
pulses and energy of any pulse, as well as suitable amount of water
between the laser irradiating tip and tooth surface.
This research have been presented in 2nd international congress of
Laser Dentistry in Dubai on 11th January 2007 by the author and is
IN PRESS in one of the high rank ISI indexed scientific journals.
For more information the interested persons could kindly write to:
As a conclusion could be addressed that there are enough evidence
which show 30 pulses per second of both wave lengths with a pulse
energy of 300 mJ and pulse length of 60-90 microseconds, could cut
the enamel even faster than high speed drills. The accuracy of cut
margins with NON-CONTACT laser handpieces could be comparable also
for preparing the
bevels and shoulders in the aim of Veneer, Inlay and Onlay, or crown
and bridge preparations.
Our master students are using this applications daily and we present
the clinical procedures world wide by video online lectures as you
could see in Figure-2. It is the wish of author to be able in near
future make the direct video conference presenting live cavity
preparations with same methods for the Indian friends as well. The
ideas are most welcome and the positive
and negative comments are open to be discussed in the dental forum
of this web site...
vol 1 number 10 march 2007)
Evaluation of the efficacy of a
collagen GBR membrane (BioMend Extend) supported by autogenous bone
grafts, for the treatment of peri-implant bony defects, during
Besides having the same criteria of a non-resorbable
barrier, special demands must be added to a resorbable barrier
because of the bioresorption process. To some extent, the
bioresorption process will always be associated with a cellular
response from the surrounding tissue, irrespective of whether the
material has been degraded by enzymatic activities or has been
hydrolyzed. Since this process entails some inflammatory response,
the subsequent inflammation should be minimal, reversible, and not
interfere with regeneration. Moreover, the bioresorption process
must be controlled so that membrane is maintained for a sufficient
length of time to perform its function for tissue guidance during
the initial healing period (Gottlow 1998).
Ideally, a bioabsorbable material should be safe, cost effective,
easy to use, remain in place until regeneration has occurred, and
not to interfere with newly formed tissue. Furthermore, they should
be limited to areas with minimal gingival recession and sufficient
width and thickness of keratinized gingiva, where primary closure is
sure to be achieved (Becker et al., 1996). Bioresorbable barrier
membranes used for GBR include collagen, oxidized cellulose and
polylactic-polyglycolic acid co-polymers.
A study was carried out to evaluate the efficacy of polylactic acid
and polyglycolic acid (PLA/PGA) resorbable membranes in conjunction
with autogenous bone grafts when used for the treatment of implant
dehiscences and/or fenestrations versus (e-PTFE) non-resorbable
membranes. A slightly higher percentage of bone fill was found in
the e-PTFE group (98.20%) than in the PLA/PGA group (88.56%), but
the difference was not statistically significant (Simion et al.
Hurzeler et al. 1997 performed a study on GBR around dental implants
placed in atrophic alveolar ridges using an experimental, nonporous
bioresorbable barrier made of poly D, L-lactid-co-trimethylencarbonate
and non-resorbable (e-PTFE) membranes were used as a control group.
The mean direct mineralized bone-to-implant contact length fraction
was 32% of the total implant length in the test sites and 58% in the
control sites. Control sites exhibited significantly greater bone
fill compared to the experimental sites. Histologic observations of
test specimens demonstrated a moderate inflammatory reaction related
to the degradation and resorption products of the barrier.
Synthetic bio-resorbable membrane barriers were claimed to cause
clinical problems. Infections and inflammatory reactions were
observed around breakdown debris of Guidor membrane barriers (polylactic
acid type) (Schmitz et al. 2000).
Among the bioabsorbable materials, collagen which is the most
important structural protein component of the body, naturally
bioabsorbable, with proven medical applications, the use of collagen
as a biomaterial has been advocated based on several factors such as
its favorable role in cellular development, wound healing, and blood
coagulation (Zahedi et al. 1998).
Because collagen is the most abundant protein in the body the search
for a biodegradable material has lead to the development of collagen
membranes, which have been used in medical fields for decades (Chen
et al. 1995).
It had been reported that there is a similarity between collagen in
human skin and certain animal tissues. Since human body enzymes can
degrade animal collagen, so animal collagen is attractive as a GBR
barrier material. Collagen membranes currently available are of
various subtypes, but usually fabricated with type I collagen
derived from various bovine, porcine or equine animal sources and
harvested from tendon or dermis (Tripletti et al. 2001).
Collagen barriers are manufactured using extrusion-coagulation and
air drying which forms sheets of material from dilute collagen
solutions. The collagen is dissociated, purified and reconstituted
before final sheet forming to reduce the potential for antigenic
response when the material is implanted. Most collagen barriers are
cross-linked to increase their strength, extend their resorption
time and reduce their potential antigenicity (Wang et al. 1998).
Collagen is bioresorbable. During enzymatic degradation it will
incorporate with the flap to support the new connective tissue
attachment. This may result in augmenting tissue /flap thickness to
further protect underlying bone formation and prevent future bone
loss. Unlike some acid-based resorbable membrane materials, it does
not release acid byproducts into the wound areas as the material
breaks down (Pitaru et al. 1989).
In order to evaluate the biocompatibility and resorption pattern of
a human collagen graft material in both in vitro and in vivo, human
collagen extracted from placenta was implanted subcutaneously in 10
Sprague Dawley rats. The graft was encapsulated by day 7 and was
slowly resorbed over 56 days with minimal inflammatory response (Quteish
et al. 1991).
Ideal barrier membrane should stay in place for at least 4 to 6
weeks before being surgically removed, so the bioresorbable
membranes as collagen barrier membrane should not degrade before a
sufficient time to enhance regeneration. Many steps have been taken
to delay its degradation process. This could be achieved either by
increasing their structural integrity by cross-linking or by
delaying the degradation process using metalloproteinase inhibitors
which inhibit metalloproteinases responsible for degradation.
Various cross-linking techniques have been developed. These include
ultraviolet light (Pitrau et al. 1988), hexamethylene diisocyanate (HMDIC)
(Minabe et al. 1989 and Kodma et al. 1989), glutaraldehyde plus
irradiation (Quteish et al. 1992), and diphenylphosphorylazide (DPPA)
(Brunel et al. 1996 and Zahedi et al. 1998). The glutaraldehyde
technique was reported to leave cytotoxic residue during the process
and to overcome the drawback of this technique, the
diphenylphosphorylazide (DPPA) technique was developed.
The use of collagen membranes has not yet been approved by the
United States Food and Drug Administration (FDA) for treatment of
dehiscences associated with implants due to lack of researches
concerning this matter (Wang and Carroll 2001).
Some animal studies were carried out to evaluate the efficacy of
collagen barrier membranes in GBR. In a pilot study, Colangelo et
al. 1993, created through and through defects on the lateral aspect
of rabbit mandibles and then treated them with either a cross-liked
bovine tendon type І collagen membrane or no-treatment control. The
histologic evaluation at 30 days demonstrated a nearly complete
continuous layer of lamellar bone with osteoblastic activity in the
collagen membrane-treated group compared to only fibrous connective
tissue in the control group.
Another study was carried out in 1993 by Sevor et al. Buccal
dehiscences were surgically induced in dog mandibles. Implants were
then placed in a random pattern in both sides of the mandibles (two
of each type of implant in each side of the mandible). A resorbable
collagen barrier membrane (CollaTec) was placed around one pair of
implants on each side. The other two implants on each side served as
controls. The sites were examined clinically and histologically
after 4 or 8 weeks to assess bone regeneration. At 4 weeks, the mean
defect fill was 69.16% in the collagen membrane-treated group
compared to 24.07% in the control group. At 8 weeks, the mean defect
fill was 80.29% in the collagen membrane-treated group compared to
38.62% in the control group. The author also reported excellent
wound healing at experimental sites in contrast to results with
other materials. He suggested that as collagen products have been
extensively utilized to heal burns and to dress surgical wounds,
collagen has been found to be a chemoattractant for fibroblasts and
connective tissue elements. Examination of certain histologic
sections in the present study showed that bone and bone elements
proliferated in close approximation to the collagen membranes.
Zahedi et al. 1998 performed a study to evaluate the potential of
Calfskin origin collagen membrane (Paroguide) in the healing of
mandibular bone defects. The experiment was carried out on 25 Wistar
rats. After exposing the mandibular ramus bilaterally, 5 mm diameter
full-thickness circular bone defects were surgically created. Defect
on one side was covered by the membrane (experimental), the defect
on the other side was left uncovered (control) before closure of the
overlying soft tissues. In the 90 and 180 day animals, all
experimental defects were completely closed. While in control
defects, no statistically significant increase in bone regeneration
Francisco et al. 2000 have clinically evaluated an absorbable a
porcine dermis origin collagen membrane (Bio-Gide) and a non
resorbable (PTFE) membrane, associated with or without deproteinized
bovine bone mineral xenografts (BioOss), for the treatment of
ligature-induced peri-implantitis defects in dogs. The results
showed percentage vertical bone fill with use of the resorbable
membrane alone (21.78±16.19) and with the use of resorbable membrane
together with BioOss (27.77±14.07). With use of non-resorbable
membrane the percentage of vertical bone fill was (18.86±10.63) and
with use of non-resorbable membrane togther with BioOss it was
(19.57±13.36). However, he concluded that no significant statistical
difference was detected among treatments.
A comparative analysis between two different collagen membranes to
treat peri-implant buccal dehiscence defects in eight mongrel dogs
was performed. The study compared Bio-Gide to BioMend Extend (Bovine
tendon origin) collagen barriers, also the study included control
sites which were left without barrier. Clinical reentry was carried
out after 4 weeks and after 16 weeks. After 4 weeks the defect
height was 3.08±0.10 mm in BioGide barrier group, 3.28±0.11 mm in
BioMernd Extend barrier group, and 3.41±0.12 mm in control group.
After 16 weeks the defect height was 3.29±0.12 mm in BioGide barrier
group, 3.11±0.11 mm in BioMernd Extend barrier group, and 3.091±0.15
mm in control group. The sites treated with barriers showed higher
percentage of bone fill and bone-to-implant contact, however, sites
treated with BioMend Extend demonstrated significantly greater
bone-to-implant contact than sites treated with Bio-Gide barriers
(Oh et al. 2003).
Few clinical studies were carried out to evaluate the efficacy of
collagen barriers for treating dehiscence defects around dental
implants. Zitzmann et al. 1997 studied GBR using Bio-Gide collagen
membrane versus (e-PTFE) for treating 84 exposed implant surfaces,
both were supported with BioOss. Bone fill was achieved for the
collagen membrane group was 92% against 78% bone fill for the (e-PTFE)
membrane group. In the latter group, 44 % wound dehiscences and/or
premature membrane removal occurred.
Paroguide collagen membrane was evaluated for GBR to treat patients
with insufficient ridge width (less than 5 mm). The membranes were
supported by collagen sponges to maintain the space buccally and
lingually. The defects which demonstrated sufficient width for
implant placement were 75%. Mean increase in the size of the crest
was 2.5 mm (3 to 5.5 mm) (Parodi et al. 1998).
Another study was performed by Nemcovsky et al. 2000, where buccal
dehiscence defects were treated with GBR procedures using resorbable
Bio-Gide collagen membrane supported by bovine bone mineral after
the placement of 28 implants in 21 patients. Mean defect area at the
time of implant placement was 23.7 mm². Implants were uncovered 6 to
8 weeks later. The mean defect area at the time of uncovering was
0.7mm². The mean percentage of defect reduction (clinical bone
fills) was 97%.
Carpio et al. 2000 compared the efficacy of a porcine-derived
bioresorbable Bio-Gide collagen membrane versus an (e-PTFE) membrane
for GBR using a bovine bone xenograft/autograft composite in defects
surrounding dental implants. Defect size was recorded at stage 1 and
2 surgeries (performed 6 months apart). At baseline, the defect
height in the group treated with collagen barriers had a mean of
4.63±0.49 mm and the defects width had a mean of 3.36±0.28 mm. The
defects height in the group treated with (e-PTFE) barriers had a
mean of 4.18±0.39 mm and the defects width had a mean of 4.36±0.40.
After 6 months reduction in defect height was 2.65±0.61 mm and
reduction in defect width was 1.95±0.60 in group treated with
collagen barriers. The reduction in defects height was 2.26±0.61 mm
and reduction in defects width was 2.65±0.56 in group treated with
Hämmerle and Lang 2001 carried out a study to evaluate efficacy of
Bio-Gide collagen membrane supported by BioOss for GBR to treat
buccal dehiscence defects around dental implants. The study included
10 patients. At baseline, the deepest extensions of the defects were
located at the buccal aspects (mean 7.8 mm, SD 1.9 mm). At re-entry,
the mean defect had decreased to 2.5 mm (SD 0.6 mm). This difference
was statistically significant (P < 0.01). Initially, in 62% of sites
the depth ranged from 0-3 mm, in 23% it ranged from 2-4 mm, and in
15% it amounted to more than 6 mm. Six to 7 months later, at
re-entry, 95% of sites were 3 mm and less in depth and 5% ranged
from 4-6 mm. Defect resolution, as assessed by the amount of
coverage of the initially exposed rough implant surface reached a
mean value of 86% (SD 33%). One hundred percent resolution was
accomplished at 8 out of 10 implants, 60% at one and 0% at another
Brunel et al. 2001 performed 7-year follow up for GBR prior to
implant placement using Paroguide collagen membranes supported by
hydroxyapatite (HA) crystals. The results showed bone filling at a
treated sites and osseointegration rate of 86% after 7-year
observation period. He concluded that these results confirm the
possibility of regenerating bone by means of bioresorbable
membranes, assuring at the same time the long-term success for
implants inserted in regenerated sites.
Tawil et al. 2001 evaluated the efficacy of a bioresorbable collagen
membrane (Bio-Gide) in combination with autogenous bone graft in the
treatment of peri-implant dehiscences, fenestrations, or limited
vertical defects. Autogenous bone was used in all cases to fill the
defect and maintain the space underneath the barrier. The membrane
absorbed the blood and easily covered and adhered to the underlying
bone. It was not stabilized by any retentive means. Sixteen to 32
months postoperatively, the sites were re-entered and the amount of
bone regenerated was measured. The mean defect height and width
respectively were 5.28mm and 3.11mm at the time of the first
surgery. At the time of second surgery the mean defect height and
width respectively were 0.61 mm and 0.94 mm. The results showed
significant bone gain (average 87.6%) in the treatment of peri-implant
bony defects with Bio-Gide and autogenous bone.
Regarding the quality of bone gained through GBR by the use of
collagen barriers, it was proved that collagen barriers provided
qualitative bone regeneration comparable to the standard (e-PTFE)
material as assessed by histological examination (Friedmann et al.
Zahran and Al-Shirbiny 2003 studied the efficacy of a bioabsorbable
collagen membrane (BioMend Extend) in combination with decalcified
freeze-dried bone allograft (DFDBA) in the treatment of peri-implant
dehiscence defects. Ten patients having twelve endosseous implants
with buccal dehiscence defects were included in the study. Surgical
re-entry was carried out 6 to 9 months post surgically, in
conjunction with abutment connection. The initial height of the
dehiscence defects ranged from 3 to 6 mm with an average of 3.95 mm.
On re-entry, the height of the residual defects varied between 0 to
1.5 mm with a mean value of 0.66 mm with an average of 84.76%
±11.81% of defect fill. Four defects out of 12 showed 100% vertical
bone gain. The initial width of the dehiscence defects ranged from 2
to 3 mm with an average of 2.33 mm. The residual width of defects
varied between 0.0 to 1.00 mm with a mean value of 0.08 mm.