Open Journal of Stomatology, 2013, 3, 370-378 OJST
http://dx.doi.org/10.4236/ojst.2013.37063 Published Online October 2013 (http://www.scirp.org/journal/ojst/)
A novel bio-sensor for registration of biting force in
occlusally reactive single mandibular implant overdenture
Fahad H. Banasr, Manal R. Alammari
Oral and Maxillofacial Rehabilitation, Faculty of Dentistry, Dental Hospital, King Abdulaziz University, Jeddah, Saudi Arabia
Received 26 July 2013; revised 26 August 2013; accepted 20 September 2013
Copyright © 2013 Fahad H Banasr, Manal R Alammari. This is an open access article distributed under the Creative Commons At-
tribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is prop-
erly cited.
ABSTRACT
Mandibular single denture opposed by maxillary na-
tural dentition showed a great problem. However,
mandibular implant overdenture treatment has gained
considerable recognition. Ten male patients with com-
plete mandibular edentulous arch and opposing arch
have full natural dentition. Patients were divided into
two groups. All patients received two endosseous tita-
nium implants. In Group I, patients were rehabili-
tated with conventional implant retained overden-
tures. While in Group II, Patients were rehabilitated
with occlusal reactive implant overdentures. A Novel
proposed bio-sensor was used to measure the amount
of biting force on the implant retained overdenture.
Quantitative electromyographic (EMG) signals of the
masseter and anterior fibers of temporalis muscles
were recorded, filtered and directly interfaced with a
computer to represent the data graphically. The
mean amplitude (µV), turn, and activity were re-
corded at the baseline and after three months. The
results revealed an increase in the muscle activity in
group II after three months as compared to group I.
Significant difference in bilateral biting force at the
premolar-molar area was found between group I and
group II after three months. This study concluded
that a resilient implant overdenture denture could be
a desirable treatment in mandibular overdenture
supported by two implants with resilient attachment
and opposing natural dentition due to its easy fabri-
cation and durability in use and increased muscle
activity.
Keywords: Bio-Sensor; Biting Force; Mandibular
Implant; Resilient Overdenture
1. INTRODUCTION
The main principle of any prosthetic treatment was based
on the reduction of the transmitted load to the supporting
structures. This can be achieved by improvement of den-
ture retention, support, stability and reduction of the oc-
clusal table, the broad coverage and the use of resilient
materials. Mandibular single denture opposed by maxil-
lary natural dentition showed a great problem due to
smaller basal seat area of the mandibular arch com-
pared to the maxillary arch and also greater forces trans-
mitted to the supporting structures that are unable to re-
sist them adequately. It is not known how much force is
exerted when natural teeth in one arch are opposed by
complete denture [1]. The resultant was a chronic sore-
ness of the soft tissue, resorption of the alveolar ridge
and inability to wear the denture. In recent decade, im-
plant supported restoration has proven to be a reliable,
predictable and effective treatment modality. Nowadays
it appears that mandibular implant supporting overden-
tures are particularly successful and the use of implants
has a great impact on the prosthodontic treatment of the
edentulous patient. The treatment planning of edentulous
jaw depends on the prosthetic design for distribution of
implants over the arch, their location and their number.
Moreover, it depends on the natural dentition or type of
prosthesis in the opposing jaw and the occlusal scheme
[2-5].
Over time, mandibular implant overdenture treatment
has gained considerable recognition. It is an attractive
treatment alternative because of its relative simplicity,
invasiveness, and affordability. The prosthesis is sup-
ported by implant and mucosa and generally requires a
smaller number of implants when compared with the
totally implant supported prosthesis design. Fewer im-
plants and a removable prosthesis offer a less complex
and less expensive alternative for an edentulous Mandi-
ble [6].
Mandibular overdentures supported by only a few in-
fraforaminal implants are regarded today as a geriatric
treatment modality. The placement of only two implants

F. H. Banasr, M. R. Alammari / Open Journal of Stomatology 3 (2013) 370-378 371
will minimize the risk to patients and tissues. It consid-
ered as a true alternative to fixed prostheses in terms of
economics and time-saving procedures. The combined
mucosa implant supported overdenture is attached to two
implants by means of resilient stud attachment or mag-
nets [7].
There are many different attachments provided by a
large number of manufacturers around the world. Most
of these are compatible with the majority of the implant
systems currently available and are divided into two ma-
jor categories: bar and stud attachments. The choice of
attachment is based basically on opinions and clinical
experience rather than on real evidence and scientific
findings [8]. Factors of selection attachment systems
depend on the amount of space available, maintenance
requirements, load distribution to the mucosa and to the
implants, and the degree of retention [9,10].
Implant overdenture construction necessitates the ex-
istence of sufficient room for the accommodation of the
attachments. Lack of space can result in esthetic prob-
lems, fracture of the acrylic resin, or other technical
problems [11]. Besides the necessary vertical space for
the housing of the attachment, sufficient horizontal space
is also critical for the structural integrity of the prosthesis.
The O-ring is perhaps the most popular stud attachment
which is available to the dental profession to increase the
retention of implant supported overdentures. O-rings are
elastomeric retentive attachments which are usually
made of silicon and shaped like the inner tube of a tire.
They are held within metallic retaining rings with un-
dercut groove. The retaining rings are embedded within
the denture base resin during the laboratory procedure or
chair side with auto-polymerizing resin [12].
Occlusion also can be critical for implant longevity
because of the nature of the potential load created by
tooth contacts and the impact on the attachment of the
bone to the titanium implant. In the natural dentition, the
periodontal ligament has the capacity to absorb stress or
allow for tooth movement, but the bone-implant interface
seemingly has no capacity to allow movement of the
implant. Vertical loads from mastication induce axial
forces and bending movement that result in stress gradi-
ents in the implant as well as in the bone. A key factor
for the success or failure of a dental implant is the man-
ner in which stress is transferred to the surrounding bone
[13].
The need for reduction of traumatic forces transmitted
through the prosthesis has long been recognized and
studies have shown that either a soft acrylic resin/sili-
cone rubber can serve as a stress distributor and absorb
some of the forces applied to the teeth. These dentures
permit reaction to impact forces which allows independ-
ent movement of one or more teeth in function unlike the
conventional dentures [14].
Bite force (BF) results from the combined action of
the jaw elevator muscles modified by jaw biomechanics
and reflex mechanisms. The determination of individual
bite force levels was done to understand jaw muscles
strength, muscle function and activity and for evaluation
of therapeutic effect of oral prostheses [15].
The most common technique for measuring BF was
strain gages. They offer many advantages over other
techniques such as simple installation that can be carried
out with little training, available circuitry to measure its
linear output over a large range of forces because of its
easy estimation of the magnitude of the gage output with
little well defined calculations. However, the resistance
strain gages have their limitations. One of the most im-
portant limitations is the large size of the gauge applied
to BF transducers. The large size of the gauges requires
the height of the BF transducer to about 10 millimeters
which causes a bite opening. This mouth opening will
initiate a movement of the condyle along the articular
eminence and therefore change the relationship to the
closing muscles [16,17]. The non-linearity of human
Biting Force (BF) provides a non-accurate computational
analysis results. Recently the force sensing resistor, sur-
face material of the sensor, and the computational soft-
ware are important for determination of dental func-
tional loading levels and increasing the medical analysis
accuracy [18,19]. Therefore, this research was conducted
to record the biting force and electromyographic activity
resulting from occlusal reactive mandibular implant
overdenture opposed by natural dentition.
2. MATERIALS AND METHODS
The study was reviewed and approved by Research Eth-
ics Committee at the Faculty of Dentistry, King Abdu-
laziz University. The study design was explained to the
patients and a signed consent was obtained from each
patient. Ten male dental patients with complete man-
dibular edentulous arch, were selected from the Prostho-
dontic Department, King abdulaziz University, Dental
Hospital. The opposing maxillary arch was full natural
dentition. Their age ranged from 45 to 60 years. They
were willing to accept mandibular implant over-denture
treatment modality. They were healthy, free from any
systemic disease with an acceptable level of oral hygiene.
They were not subjected to chemotherapy or radiother-
apy. Routine laboratory and medical investigations were
performed for the patients undergoing implant surgery.
Panoramic x-ray was made for every patient.
After collecting all the required diagnostic records for
each patient. The patients were divided into two groups,
group I and group II, each of five. Group I, the patients
were rehabilitated with conventional implant retained
mandibular overdentures. While in Group II, the Patients
were rehabilitated with occlusal reactive mandibular

F. H. Banasr, M. R. Alammari / Open Journal of Stomatology 3 (2013) 370-378 372
implant overdentures.
In group I: conventional standard technique for man-
dibular single complete denture construction was used.
Minor occlusal adjustment for natural teeth was carried
out within the enamel. Posterior teeth were rearranged to
satisfy the requirements of balanced occlusion. Adjust-
ments in the artificial teeth were incorporated in prefer-
ence to natural teeth. The finished dentures were deliv-
ered to the patient after performing the needed occlusal
adjustment.
In group II: the occlusal reactive mandibular denture
(Figure 1) was constructed as follow: the denture base
was processed and used for jaw relation records. After
the try-in stage, the regular procedure of flasking and
wax elimination were carried out. A standard spacer of
two strips of 0.001 tin foil was adapted under the artifi-
cial teeth in the flask and the split packing technique was
followed by using a cellophane separator. The flask was
opened, diatoric holes were made in the denture tooth
with undercut to allow chemical bonding with soft resin.
The spacer removed and sufficient amount of super soft
resin (SS, GC America Inc., USA) was then applied and
the dentures were processed [20].
Radiographic surgical stent was fabricated from clear
heat acrylic replica of the constructed mandibular com-
plete denture of both groups.
All the patients (group I and group II) received two
endosseous titanium implants in the mandibular symphy-
sis area (Imtec endure Co., USA). Mandibular over-
denture with O-ring attachment over the implant was
incorporated in the base of patient's denture. After two
weeks the superstructures were attached to implant (they
consist of O-rings, keeper and ball insert attachment
(Figure 2) then connecting o-ring attachment to the
(a)
(b)
Figure 1. Occlusal reactive denture (a) bucal view,
(b) lingual view.
existing mandibular complete denture by direct clinical
procedure as follow: The fitting surface of mandibular
complete denture (in group I and group II) was relieved
to create space for the metal housing (an elastic shim
spacer) was placed around the O-ring assembly on the
implant in the mouth to protect the gingiva from acrylic
resin seeping into the mucosa and prevent acrylic resin
from adhering to the implant) (Figure 3). Such spaces
were filled with autopolymerized acrylic resin (Acros-
tone Cold Cure Acrylic Resin, Acrostone Co., England)
at dough stage, the dentures were seated in the patient
mouth (at centric relation) and to pick up the metal
housing in the fitting surface of mandibular denture
(Figure 4). The denture was removed, cleaned and ex-
amined for the orientation of the attachment inside the
denture base. The elastic shim was removed. Smoothing
and polishing the surface of the denture base were car-
ried out and then occlusal equilibration was completed.
Patient was motivated for oral hygiene procedure and
then scheduled for radiographic examination.
Novel Proposed Bio-Sensor for Recording the
Biting Force
A Novel proposed bio-sensor [18] was used to measure
the amount of biting force on the implant retained over-
denture. The sensor had been designed and encapsulated
into a conventional safe bite guard. It had three major
components: an inner sensor, an intermediate activator
and an outer surface. The inner sensor was made of a
circular conductive polymer pressure-sensing resistor. It
Figure 2. Superstructures were attached.
Figure 3. Elastic shim spacer was around the
O-ring assembly on the implant.

F. H. Banasr, M. R. Alammari / Open Journal of Stomatology 3 (2013) 370-378 373
had two sheets were separated by a spacer that increased
the peripheral thickness of the sensor to 0.5 mm. Its basic
characteristics were piezoresistive (piezo is derived from
the Greek word piezein, “to squeeze”) i.e. its resistance
decreases with increasing normal pressure, the thermo-
plastic sheets also insulated the sensor. The proposed BF
biosensor module produces frequency modulation using
the FMC (force measuring circuit). These frequencies are
transmitted to a microcontroller programmed in the man-
ner that every received frequency is encoded into a re-
corded BF in Newton displayed on a LCD screen (Fig-
ures 5 and 6).
(a) (b)
Figure 4. Pick up the metal housing in the fitting surface of mandibular denture.
Figure 5. Proposed system diagram consisted of 1) piezoresistive sensor, 2) resitance to frequency cpnverter,
3) microcontroller based electronic circuit, 4) BF displayed on LCD screen.
(a) (b)
Figure 6. Flexiforce Sensor Components and 1) slide resistance, 2) two steel support and 3) steel spring.

F. H. Banasr, M. R. Alammari / Open Journal of Stomatology 3 (2013) 370-378 374
3. CALIBRATION OF THE SENSOR
Prior to intraoral measurement, the sensor bite force were
calibrated and measured at different values of perpen-
dicular forces against a universal testing machine (In-
stron Type 3382, German). The sensor was connected to
micro-controlled electronic measuring circuit. The output
signal from the load cell was conditioned, amplified and
then recorded in a software program (Bluehill2). The
correlation between the force recorded by Bluehill pro-
gram according to the load cell and readout frequencies
were recorded and plotted to calculate the linear equation
between them (Figure 5).
3.1. Procedure of Recording BF
Patients were seated upright in the dental chair. They
instructed to bite on the bite sensor device with closed
and relaxed lips. Series of measurement at the right and
left premolar-molar sides of the jaw were recorded with
one minute rest between trials. The module output BF is
measured and average value was calculated and recorded.
The readings were recorded immediately at the day of
insertion and after three months for group I and group II.
3.2. Recording the Electromyographic Activity
A quantitative EMG of the masseter and anterior fibers
of temporalis muscles (representing the electrical activity)
was recorded by means a standard electromyographic
apparatus (Dentac Key Point Apparatus, Dentac Mod. 33
- 49, Denmark) at the baseline and after three months
follow up periods. The patient was seated upright in a
relaxed position without head support. The patients were
instructed for wearing their dentures at least two hours
before making the records. The two muscles studied
(masseter and anterior fibers of temporalis) were first
located. Skin was carefully cleaned prior to electrode
placement, [21] with 70% isopropyl alcohol allowing the
conductive paste to moisten the skin surface adequately.
An electroconductive paste (Ten20, D.O.Weaver and Co,
565-B Nucla way. Aurora, Co 80011, USA) was used as
a conductive and fixing medium between skin and sur-
face electrode. Patients were asked to close with maxi-
mum force for 10 seconds during which the EMG appa-
ratus recorded free run EMG signals. This process of
maximum biting and recording EMG signals was re-
peated 20 times in all. A rest period of 15 - 30 sec was
allowed between individual recording to avoid muscle
fatigue.
The amplifier set up was set at sweep speed 100
ms/division, sensitivity 200 µv, division filter setting 20
Hz - 10 KHz. Analysis of interference pattern (IPA) in-
cluded three parameters 1) Number of turns (NT) or
number of potential reversal of more than 100 µV per
time unit independent of baseline, 2) Mean amplitude
(MA) of the average is the amplitude between two turns
measured by µV and 3) Activity that measured the full-
ness of IPA was defined as the time with electromyog-
raphic activity measured in milliseconds [22,23].
Electromyographic signals were recorded, amplified,
filtered and directly interfaced with a computer to repre-
sent the data graphically. The data for the EMG activity
was recorded for the right and left sides of both groups.
3.3. Statistical Analysis
All statistical analyses were performed using Statistical
Package for the Social Science software (SPSS, version
17, Chicago, IL, USA). Descriptive statistics as means
and standard deviations were used. T-test (unpaired)
value of significance at 5 percent was performed for
comparison between means at the baseline of implant
over-denture insertion and after three-month follow up
periods for each group. Paired t-test value was used for
comparing between baseline and after 3 months in each
group.
4. RESULTS
A calibration curve was showed in Figure 7, the plotted
calibration was linear and the measurements were re-
peatable.
The mean value of amplitude (µV), mean turn and
mean activity of masseter muscle was showed in Table
1.
The mean value of amplitude (µV), mean turn and mean
activity of masseter muscle at the base line in group I and
group II was not statistically significant.
Comparison between group I and group II for the
mean value of amplitude (µV), mean turn and mean ac-
tivity of masseter muscle after three months follow up
periods showed a significant difference at 5% level (P1 =
0.001).
Comparison between group I and group II for the am-
plitude (µV), mean turn and mean activity at baseline
and after three months of follow up periods showed a
significant increase at 5% level (P2 = 0.001).
The mean value of the amplitude (µV), mean turn and
mean activity of temporalis muscle of group I and group
II was showed in Table 2. Comparison between the
mean amplitude (µV) of group I and group II at the base
line showed statistical significant difference (P1 = 0.001),
and after three months showed also statistical significant
(P2 = 0.001) at 5% level. Comparison between the base-
line of group I and group II as regards the mean ampli-
tude (µV) with three months follow up periods showed a
statistical significant difference at 5% level (p2 < 0.001).
Comparison of the mean turn and mean activity of
group II at the baseline was not statistical significant.
Also after three months follow up periods showed no

F. H. Banasr, M. R. Alammari / Open Journal of Stomatology 3 (2013) 370-378 375
Figure 7. Plotted calibration curve between the output frequency circuit and
the resultant of programmed microcontroller was linear.
Table 1. Comparison of electromyographic parameters of masseter muscles bilaterallyat different follow up periods in the two study
grops.
Group I Group II p1
Baseline Mean ± SD 395.60 ± 4.62 401.60 ± 5.03 0.085
After 3 months Mean ± SD 605.40 ± 4.56 619.80 ± 1.48 <0.001*
Amplitude (µV)
p2 <0.001* <0.001*
Baseline Mean ± SD 210.20 ± 3.19 214.20 ± 4.21 0.129
After 3 months Mean ± SD 325.0 ± 4.12 238.0 ± 7.58 <0.001* Turn
p2 <0.001* <0.001*
Baseline Mean ± SD 12.80 ± 1.30 12.56 ± 0.52 0.712
After 3 months Mean ± SD 16.0 ± 1.22 21.0 ± 1.41 <0.001* Activity %
p2 <0.001* <0.001*
p1: p value for Student t-test for comparing between the two studied group; p2: p value for Paired t-test for comparing between baseline and after 3 months in
each group; *: Statistically significant at p ≤ 0.05.
Table 2. Comparison of electromyographic parameters of temporalis muscles bilaterally at different follow up periods in the two
study groups.
Group I Group II p1
Baseline Mean ± SD 367.0 ± 3.91 393.40 ± 3.44 <0.001*
After 3 months Mean ± SD 415.40 ± 3.91 553.40 ± 3.97 <0.001*
Amplitude (µV)
p2 <0.001* <0.001*
Baseline Mean ± SD 247.80 ± 59.61 200.60 ± 7.02 0.152
After 3 months Mean ± SD 313.0 ± 4.95 308.20 ± 5.76 0.195 Turn
p2 0.084 <0.001*
Baseline Mean ± SD 10.90 ± 1.39 12.0 ± 3.08 0.488
After 3 months Mean ± SD 18.0 ± 3.39 19.0 ± 2.92 0.631 Activity %
p2 0.002* 0.091
p1: p value for Student t-test for comparing between the two studied group; p2: p value for Paired t-test for comparing between baseline and after 3 months in
each group; *: Statistically significant at p ≤ 0.05.

F. H. Banasr, M. R. Alammari / Open Journal of Stomatology 3 (2013) 370-378 376
statistical significant.
Comparing the mean turn of group II at the baseline
with the three months was statistically significant (P2 <
0.001).
A statistical significant difference was observed in the
mean activity of group I between the base line and after
three months (P2 = 0.002).
Comparison between the mean value of bilateral biting
force of premolar-molar area at the baseline and after
three months of follow up periods for both group I and
group II showed a statistically significant at 5% level (P1
= 0.014 0.003), respectively as shown in Table 3.
Comparison between groupI and group II of bilateral
biting force of premolar-molar area at the baseline with
three months follow up period showed statistical signifi-
cant increase at 5% level (P2 = 0.001 and 0.001).
The mean value of anterior biting force in group I and
group II was showed in Ta ble 3, there was no statistical
significant difference between group I and group II at the
baseline, while after three months follow up period there
was a statistical significant difference at 5% level (P1 =
0.007).
A statistical significant increase in anterior biting force
was observed in group I and group II after three months
follow up periods (P2 = 0.003 and 0.007) respectively at
5% level.
5. DISCUSSION
Mandibular two implant overdenture have been recog-
nized as the first choice of treatment for edentulous pa-
tients when compared with conventional complete den-
ture. The main factors associated with the superior effec-
tiveness are due to retention and stability provided by the
attachment mechanism connecting the implant to the
denture base. Different attachments together with two
implants retained overdenturess, represent a predictable
and successful option to treat edentulous patients [24].
Selected patients had full complement of natural teeth
opposing to edentulous mandibular arch as it would af-
fect the functional state of the masticatory system and so
the maximum voluntary occlusal force. Occlusal form of
the remaining natural teeth, can dictate the occlusal form
of the denture. The natural teeth may be over-erupted or
tilted and their cusps high and sharp. As a result, occlu-
sion and articulation will involve contacting of the in-
clined planes of the cusps in such a way that the denture
will continually be thrust or dragged horizontally on the
ridge. Additionally minor occlusal interferences included
in this study were adjusted for establishing free occlusion.
Literature recommended in these cases a minimum of
four implants with a fixed implant prosthesis as the con-
dition of the opposing jaw influences the occlusal con-
cepts. However, the recent literature review exhibits a
high success rate for using fewer implants (two) for
mandibular overdenture with resilient attachment system
in older patients in terms of economics and time saving
procedures and at the same time minimizes the risk to
patient and tissues [3].
The occlusal reactive mandibular implant overdenture
was used in our study. It was made of resilient zone in-
terposed between a rigid denture base and the artificial
teeth which may be contributed to reduce the occlusal
load transmitted to the implant and minimize the effect
of deflective occlusal contacts [20].
BF determined in this study by novel proposed
bio-sensor because it is safe, easy to fabricate, chemi-
cally and physically stable with high sensitivity. The
novel sensor based on conductive polymer film useful
for determination of occlusal loading level and function-
ing as force absorber and not damaged or ruptured by
tooth cusps. The material used was soft and allowed the
test patient to obtain a firm grip in all position. The con-
ductive material are sensitive to mechanical stress that
can be molded into various shapes and sizes with spring
fixed to variable resistance compressed and can be
measured using the connected circuit. This sensor exhib-
Table 3. Comparison of the mean value of the bilateral bilateral biting force at premolar molar region and anterior region in the two
study groups.
Group I Group II p1
Baseline Mean ± SD 185.40 ± 10.36 201.80 ± 5.36 0.014*
After 3 months Mean ± SD 232.20 ± 4.97 244.0 ± 4.0 0.003*
At premolar-molar region
p2 0.001* <0.001*
Baseline Mean ± SD 144.80 ± 4.32 145.80 ± 4.02 0.715
After 3 months Mean ± SD 164.20 ± 2.95 156.0 ± 4.18 0.007* At the anterior region
p2 0.003* 0.007*
p1: p value for Student t-test for comparing between the two studied group; p2: p value for Paired t-test for comparing between baseline and after 3 months in
each group; *: Statistically significant at p ≤ 0.05.

F. H. Banasr, M. R. Alammari / Open Journal of Stomatology 3 (2013) 370-378 377
ited a linear relationship between the frequency of the
circuit and the resultant of programmed microcontroller.
The significant increase of the BF in molar-premolar
area than the anterior area could be attributed to the lever
effect of the mandible and the function of implants in the
edentulous jaw was taken over by the receptors in the
mucosa and the periosteal mechanoreceptors as well as
intraosseous nerve ending and functional adaptation of
the occlusally reactive mandibular overdenture. The den-
tal implant prevents tilting of the denture during biting
and thus decrease pain factor that limits maximium BF
due to reflex mechanism. The degree of tissue support of
mandibular denture by dental implants also improves
oral function [25-27].
Quantitative electromyographic interference pattern
analysis is a non invasive, objective, and quantitative
tool for identification of the degree of muscle activity,
monitoring muscle fatigue, as well as chronic muscle
pain. Number of turns, mean amplitude and activity are
valuable parameters of IPA for assessing muscle activity
as well as the effect of therapeutic intervention. The mas-
seter and temporalis muscles are those most often as-
sessed in clinical evaluations because they are the most
superficial, and they are the only accessible to surface
EMG examination. EMG activity was recorded during
maximum voluntary clench to assess masseter and tem-
poralis muscles before treatment and in follow up as-
sessments [28-30].
Statistical analysis of the results showed that the elec-
tromyographic activity of the masseter muscle was sig-
nificantly higher than the temporalis muscle. This may
be attributed to the greater influence and the greater ef-
forts exerted by the masseter muscle on the denture than
the temporalis muscle. This result was in accordance
with the results of Landulpho [31].
In this study, the occlusal reactive implant overdenture
act as shock absorber of some of kinetic energy applied
by artificial teeth so that the hard basal seat of the den-
ture receives less impact force led to reactivation of the
motor units (MUs) and an increase in force of contrac-
tion that was reflected by an increase in interference pat-
tern parameters values as well as the occlusal force mea-
surement at different periods of follow up assessments.
These results can be explained as the force produced by a
muscle under voluntary contraction is based on the firing
frequency and the recruitment of MUs. Increasing either
the firing frequency or the number of recruited MUs
contributes to increasing the muscle force on maximum
voluntary contraction. There is a linear relationship be-
tween the force of contraction and the mean amplitude as
well as number of turns of interference pattern. At higher
levels of contraction, the firing rate of MUs has large
motor unit action potential amplitude [32,33].
6. CONCLUSION
Types of overdenture and occlusal concepts are primary
goals at the beginning of treatment. The proposed bio-
sensor is safe for introrally application (in-viv o ) without
alteration of patient bites and for evaluation of the bio-
mechanics of the prosthetic appliances. The resilient
layer denture could be a desirable treatment in mandibu-
lar overdenture supported by two implants with resilient
attachment and opposing natural dentition due to its easy
fabrication and durability in use and increased muscle
activity.
7. ACKNOWLEDGEMENTS
We are grateful to Professor Mazhar Tayel (Department of Electrical
Engineering, Alexandria University), and Professor Seham Tayel (King
Abdulaziz University) for their valuable advice and comments in this
research.
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