Bar and Ball Joint Overdentures Surface Roughness and Microbial Adherence
Phase: NA
Conditions: Adhesiveness
Sponsor: Gastrovital

 
 
 
 
 
 
 
 
 
Bar and Ball Joint Overdentures Surface Roughness and Microbial Adherence 
                                                NCT (not available) 
                                                   January 5, 2016 
 
 
 
 
 
 
 
 
 
 
 
 

STUDY PROTOCOL 
In the treatment of the mandibular edentulous the implant-retained overdenture has been shown to 
have advantages in support, retention, stability and esthetics (Stellingsma et al., 2005; Portmann and 
Galuser, 2006) improving masticatory efficiency, decreasing anterior bone loss and injury in soft 
tissues, increasing comfort, satisfaction and improvement of the patient’s health quality (Visser et al., 
2006). According to the type of anchorage recommended we have the implant-retained mandibular 
bar overdenture (BOD) and implant-retained ball joint overdenture (BJOD). Bar anchors are retention 
systems that provided adequate support for rehabilitation (Degidi and Piatelli, 2003; Elsyad et al., 
2014). By the other side the ball joint are axial anchors with retention system through threaded 
connections for mandibular prosthetic reconstruction. It is considered that regardless of the 
retention system the adjustment must be passive to the implants (Van Kampen et al., 2003). The 
structure of the overdentures consists of thermoplastic polymethacrylates which are derived from 
ethylene and contain a vinyl group resulting from the polimerization of methacrylic acid or its 
derivatives (Lang et al., 2003). These polymethacrylates must be resistant to fracture and flexion, 
properties that can be increased through zirconia or amorphous silica particles (Panyayong et al., 
2002; Uzun and Keyf, 2003). Possibly the immersion of some oral restorations in agents cleaners alter 
their structural stability (Senna et al., 2011). It is considered that the absence of porosity and 
dimensional stability increase the surface quality of the restorations, influencing the preservation of 
the mucous tissues through surfaces that facilitate the patient’s oral hygiene. Therefore, an 
important factor in reference to the quality of the mouth restorations is the surface roughness with 
importance in the preservation of the oral health in relation to the surrounding tissue (Yap et al., 
2004; Guler et al., 2005; Bollen et al., 1997). There are differences in roughness values in various 
thermoplastic polymethacrylates (Berger et al., 2006). The surface quality of the restorations and 
their relationship with the gingival tissues enable smoother surfaces to maintain the health of oral 
tissues avoiding the inflammation of them. The surfaces of the overdentures are available as 
substrates for the development and growth of microorganisms. The oral cavity presents more than 

seven hundred bacterial species (Busscher and Van der Mei, 1997) and overdentures implant-
retained are susceptible to the accumulation of microorganisms with adhesion capacity such mold 
and yeast and mesophyll aerobe. The yeasts are unicellular fungi which reproduce by budding and 
transverse division and the mold is formed by hyphae the whole of which forms a mycelium. The 
mold and yeast which cause pathology in humans are dimorphic 2 to 4 um in diameter (Radford et 
al., 1999). Other microorganisms with adhesion capacity are mesophyll aerobes which include 
bacteria that develop in the presence of free oxygen of   0.5 to 2 um in diameter (Daniluk et al., 2006; 
Busscher et al., 1986).  The permanence of BOD and BJOD depends on several factors, one of them 
being the surface roughness (Ra) and its relation with the adhesion of microorganisms. The objective 
of the study was to compare the surface roughness (Ra) of BOD compared to BJOD in relation to the 
adhesion of mold and yeast and mesophyll aerobe at 30 and 180 days of permanence in the oral 
cavity in order to stablish if there are differences in surface roughness and which of these 
overdentures are characterized by their lower roughness and adherence of mold and yeast and 
mesophyll aerobe which is an important aspect to be considered in the rehabilitation of mandibular 
total edentulous patients with implants due to their influence on oral health. 
MATERIALS AND METHODS 
The study presents the results of a sample of ten patients randomly assigned to receive 
implant-retained overdentures and divided into two parallel groups of five participants in a 
single-blind trial at a follow-up period of 30 and 180 days permanence in the mouth. Five 
overdentures were made for each group: Group 1: BOD: five systems titanium bar CARES® 
and synOcta® Straumann® Dental Implant System, Holding AG Inc., Basel, Switzerland 
(BOD). Group 2: BJOD: five systems ball joint Klockner® Implant System; Soadco Inc., 
Escaldes-Engordany, Andorra were used in two parallel groups of five participants, in an 
essay to simple blind person. The protocol was approved by Institutional Review Boards 
affiliated with the researcher. All participants gave informed consent. The inclusion criteria of 

the patients for the study were: Total edentulous mandible from 50 to 60 years of age and 
absence of systemic conditions. The exclusion criteria of the patients for the study were: 
hyperplasia and history of periodontal disease, patients with local and/or systemic 
antimicrobial treatment within 72 hours prior to evaluation during the study and signs of 
severe oral parafunction (Figure). Selected patients underwent surgery with Tapered Effect 
Implants Straumann® and Klockner Implant System®.  For the manufacture of the 
overdentures in both groups it was used as material of choice Lucitone 199® (Dentsply 
International Inc. York, PA) and for the adaptation of the retention systems it was used 
Softreliner Tough Soft® Tocuyama Dental Corporation Inc., Japan. The working protocol for 
determining the BOD Ra and BJOD Ra and the adhesion of molds and yeasts and mesophyll 
aerobics was carried out entirely by an investigator and the following working methodology 
was considered: Information to the patient of the research work to be performed. Obtainment 
of clinical data and patient informed consent. Patients were randomly assigned to group 1 and 
group 2. The saliva sample was obtained in each patient for the microbiological before the 
installation of the overdentures. BODs and BJODs were installed in each patient and 
according to each case. The BOD and BJOD were removed at 30 days for surface roughness 
evaluation (Ra:ųm) and the evaluation of the adhesion of mold and yeast and mesophyll 
aerobe (CFU/ml). For the study at 180 days the BODs and the BJODs were installed in each 
patient. BODs and BJODs were removed after this time to proceed to the evaluation of 
surface roughness and adhesion of mold and yeast and mesophyll aerobe under the same 
parameters mentioned above. 
Adherence mold and yeast and mesophyll aerobe to BOD and BJOD, Surface roughness 
(Ra), and Statistical Analyses 
Microbial populations have been controlled in the saliva at initial time and adherence at 30 
and 180 days after the overdentures in the mouth. The saliva sample was obtained from the 

patient in a sterile sputum collection bottle through a sterile solution. The overdenture 
samples were extracted and processed for analysis. Each sample was submerged in ¼ sterile 
Ringer and subjected to vigorous ultrasound shaking. From each of the microbial suspensions, 
successive dilutions were made to determine the total number of viable microorganisms 
present. Total count of mold and yeast and total count of mesophyll aerobe were performed. 
The surface roughness of BOD and BJOD was determined with the rugosimeter the Mitutoyo 
Surfest SJ-301® (Mitutoyo Corporation Inc., Kanagawa, Japan), through a displacement force 
of 4mN and of the tray to 0.5 mm/s and back to 1 mm/s (Murtra and Arcís,1999).  The 
roughness profile Ra was evaluated and determined in microns (ųm) through five readings for 
each of the samples in the study respectively.  
The results of BOD and BJOD were compared for the determination of Ra and the adherence 
of mold and yeast and mesophyll aerobe. For this, we used the statistics Shapiro-Wilk, T and 
the Pearson Correlation Coefficient to determinate the relationship between the study 
variables. For data processing and analysis the Software Package for Social Sciences (SPSS) 
version 24.0 was used.