scholarly journals Dimensional stability of distances between posterior teeth in maxillary complete dentures

2006 ◽  
Vol 20 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Rafael Leonardo Xediek Consani ◽  
Marcelo Ferraz Mesquita ◽  
Lourenço Correr-Sobrinho ◽  
Maurício Tanji
Keyword(s):  
Dimensional Stability ◽  
Storage Period ◽  
Acrylic Resin ◽  
The Other ◽  
Complete Dentures ◽  
Posterior Teeth ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Cooling Methods ◽  
Made In

The aim of this study was to assess the displacement of posterior teeth in maxillary complete dentures stored in water at 37°C. Twenty acrylic resin-based maxillary complete dentures were constructed with the anterior teeth arranged in normal overlap and the posterior teeth in Angle class I. Metallic pins were placed on the labial cusp of the first premolars (PM), and on the mesiolabial cusp of the second molars (M). The final acrylic resin pressing was made in a metallic flask with aid of the RS tension system, and polymerized in a moist-hot cycle at 74°C for 9 hours. The dentures were deflasked after cooling in their own polymerizing water or after cooling in polymerizing water plus bench storage for 3 hours, and stored in water at 37°C for periods of 7, 30, and 90 days. Following deflasking and after each storage period tested, the PM-PM (premolar to premolar), M-M (molar to molar), LPM-LM (left premolar to left molar), and RPM-RM (right premolar to right molar) distances were measured with an STM Olympus microscope, with an accuracy of 0.0005 mm. Collected data were submitted to ANOVA and Tukey's test (5%). There was no statistically significant difference for the PM-PM, M-M, and LPM-LM distances after all storage periods when the flask cooling methods were considered. With exception of the RPM-RM distance after the 30-days water plus bench storage period, the other distances remained statistically stable.

Simplified media for spiroplasmas associated with tabanid flies

2002 ◽  
Vol 48 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Rebekah W Moulder ◽  
Frank E French ◽  
C J Chang
Keyword(s):  
Costa Rica ◽  
Growth Medium ◽  
The Other ◽  
Group Viii ◽  
Field Isolates ◽  
Sustained Growth ◽  
Significant Difference ◽  
Horse Flies ◽  
Horse Fly ◽  
Made In

Traditionally, isolation, maintenance, and testing of Spiroplasma species (Mollicutes: Entomoplasmatales) from horse flies (Tabanus spp.) and deer flies (Chrysops spp.) (Diptera: Tabanidae) have been accomplished in the complex M1D medium. A relatively inexpensive, simplified medium for tabanid spiroplasmas could expedite procedures that require large quantities of growth medium. Nine strains of spiroplasmas, eight from tabanids and one from mosquitoes, were cultured in three simplified broth media, R2, R8-1, and C-3G, and in M1D. There was no significant difference in the rate of spiroplasma growth in M1D and the three simplified media. R2medium supported the growth of tabanid spiroplasmas more consistently and with better morphology through 10 subcultures than did the other simplified media. Primary isolations were made in R2medium from tabanids collected (i) in Georgia, U.S.A., with 10 isolations from 10 flies and (ii) in coastal Costa Rica, with isolation rates of 70% (28/40) and 73% (27/37), respectively, for R2and M1D. Of the seven group VIII field isolates from Costa Rica, four were capable of sustained growth in R2, and three were triply cloned in this simplified medium. These results suggest that the simplified medium R2is suitable for many procedures with tabanid spiroplasmas.Key words: simplified media, Mollicutes, spiroplasma, tabanid, horse fly.

scholarly journals Effect of Denture Base Reinforcement Using Light Cured E- Glass Fibers on the Level of Salivary Immunoglobulin A

2018 ◽  
Vol 6 (11) ◽  
pp. 2168-2172
Author(s):  
Shady M. El Naggar ◽  
Mohamed I. Seif El Nasr ◽  
Hassan M. Sakr ◽  
Sherihan M. Eissa ◽  
Asmaa N. Elboraey ◽  
...  
Keyword(s):  
Immunoglobulin A ◽  
Acrylic Resin ◽  
Enzyme Linked Immunosorbent Assay ◽  
Complete Dentures ◽  
Denture Base ◽  
Mean Values ◽  
Glass Fibres ◽  
Significant Difference ◽  
Salivary Immunoglobulin A

BACKGROUND: A gap still exists between in vitro and clinical studies concerning the biocompatibility of the material in the oral environment and their potential to cause immunological undesirable side effects. The uses of glass fibres to improve the mechanical properties of acrylic resin denture base polymers are well documented in vitro. AIM: The present study aimed to evaluate the effect of denture base reinforcement using light-cured E- glass fibres mesh on the level of salivary immunoglobulin A (S-IgA) in patients wearing complete dentures. MATERIAL AND METHODS: Fourteen completely edentulous patients, in need of complete dentures, participated in the study. The patients were divided into two groups (n = 7) according to the treatment protocol. In the first group, patients received conventional heat-cured acrylic resin dentures. In the second group, the mandibular dentures were reinforced using light cured resin impregnated E glass fibres mesh. In both groups, salivary samples were collected using passive drool technique. The level IgA was assessed by enzyme-linked immunosorbent assay (ELISA) technique at different time intervals. Statistical analysis was carried out using one-way ANOVA followed by Tukey`s post-hoc test and independent t-test. The significant level was set at P ≤ 0.05. RESULTS: Acrylic resin dentures and reinforced ones demonstrated an increase in the mean values of IgA level at the end of the follow-up intervals. And this increase was statistically significant (P ≤ 0.05). Although, the reinforced dentures revealed higher mean values, there was no statistically significant difference between the two groups (P > 0.05) CONCLUSIONS: Within the limitations of the present study, the following could be concluded: (1) the insertion of complete dentures induced changes in the level of IgA; and (2) denture base reinforcement using light cured resin impregnated E-glass fibres mesh had a similar effect to that of heat cured acrylic resin on the level of IgA.

Caries Prevalence, Severity, and Pattern in Preschool Children

2008 ◽  
Vol 9 (3) ◽  
pp. 24-31 ◽  
Author(s):  
Amjad H. Wyne
Keyword(s):  
Preschool Children ◽  
Anterior Tooth ◽  
World Health ◽  
Caries Prevalence ◽  
Posterior Teeth ◽  
Posterior Tooth ◽  
Decay Component ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Health Organization

Abstract Aim To determine caries prevalence, severity, and pattern in preschool children of Riyadh, Saudi Arabia. Methods and Materials A total of 789 randomly selected preschool children, 379 (48%) male and 410 (52%) female, with mean age of 4.7 (SD 0.5) years were examined for dental caries using World Health Organization (WHO) diagnostic criteria. Results The overall caries prevalence among the sample was 74.8%. The mean decayed, missing, and filled (dmft) score was 6.1 (SD 3.9) with a decay component of 4.66, a missing component of 0.54, and a filled component of 0.92. There was no significant difference (p>.05) in caries prevalence and severity in relation to gender of the children. However, the caries prevalence and severity were significantly higher (p<.05) among children from government preschools as compared to those from private preschools. Among the posterior teeth, mandibular second molars (54.3%), and among anterior teeth, maxillary central incisors (27.9%) had the highest caries prevalence. Among the molars, caries prevalence was generally high in lower molars while among the anterior teeth, upper teeth generally had a higher caries prevalence. The majority of the children (50.3%) had both posterior and anterior tooth caries, 42.2% had posterior tooth caries only, while very few (7.5%) children had only anterior tooth caries. Conclusion Caries prevalence and severity are very high in the study population, and most children have posterior tooth caries. Clinical Significance Early measures such as fissure sealants, topical fluoride applications (as early as safely possible), and dietary fluoride supplements (where indicated) are needed to prevent caries of deciduous molars in high caries populations. Citation Wyne AH. Caries Prevalence, Severity, and Pattern in Preschool Children. J Contemp Dent Pract 2008 March; (9)3:024-031.

scholarly journals Evaluation of Maximum Biting Force in Two Different Attachment Systems (Bollard vs. Ball and Socket) Retaining Mandibular Overdenture: A Split-mouth Design

2021 ◽  
Vol 9 (D) ◽  
pp. 47-53
Author(s):  
Reham Tharwat Kamal Elbeheiry ◽  
Gehan F. Mohamed ◽  
Amr Mohamed Ismail Badr
Keyword(s):  
Surgical Technique ◽  
Acrylic Resin ◽  
The Other ◽  
Complete Dentures ◽  
Two Stage ◽  
Occlusal Force ◽  
Edentulous Patients ◽  
The Right ◽  
Mandibular Overdenture

AIM: The study was conducted to evaluate maximum biting force (MBF) in two different attachment systems (bollard a vs. ball and socket attachment) retaining mandibular overdenture using a split-mouth design. SUBJECTS AND METHODS: Twelve completely edentulous patients received complete dentures and after adaption of the patient with the new denture, 24 implants were inserted in the canine region using two-stage surgical technique and conventional loading protocol. Six patients received the Bollard attachment at the right side and the Ball and Socket at the left side. Moreover, the other six patients received the bollard attachment at the left side and the ball and socket attachment at the right side. Each patient was treated according to split-mouth design. Insertion of each of the attachment type was assigned randomly. Using occlusal force meter instrument, MBF was measured immediately after loading (0), after 6 months (6), and after 12 months (12). RESULTS: Significant statistical differences (p < 0.05) were obvious in in MBF between Attachment (1) and Attachment (2) immediately after loading (0 months), after 6 months (6) and after 12 months (12) follow-up visits. CONCLUSION: Mandibular implant retained overdenture received Bollard abutment that retained with the denture by the help of resilient liner “Retention.sil”* without housing have higher biting forces than mandibular implant retained overdenture with ball abutment where the plastic house was picked up by monomer free self-cured acrylic resin.

scholarly journals Frequently affected teeth by different types of iatrogenic perforations made during dental training in Bulgaria

2021 ◽  
pp. 47
Author(s):  
◽  
◽  
Keyword(s):  
Treatment Failure ◽  
Root Canal ◽  
Entire Period ◽  
Patient Records ◽  
Posterior Teeth ◽  
Iatrogenic Perforation ◽  
Anterior Teeth ◽  
Different Types ◽  
Molar Teeth ◽  
Made In

Background: One of the reasons for endodontic treatment failure is iatrogenic perforation. That is why it is important to provide adequate endodontic education for graduating young practitioners. Aim: The aim of this study is to determine the most common locations of the iatrogenic perforations made by last year students in the Dental Faculty in Sofia, Bulgaria, to note the association of particular errors with particular teeth and to determine how this information can improve their education. Methods: All patient records of last-year students for 2015 and 2016 were examined. Perforations were diagnosed by radiography, and also confirmed clinically. Results: From all 778 teeth 30 incidents of root perforations were found: 10 in 2015 and 20 in 2016. More perforations were found in upper posterior teeth- 80% of all the perforations made in 2015, and 45% of all registered perforations in 2016. For the entire period of the research perforation frequency in upper molars, and in upper anterior teeth were found to be significantly higher than in other group of teeth. In academic 2015 year, 8 of the perforations (80%) were furcal. In 2016 year, 11 (55%) of all perforations were apical. Conclusions: More in-depth knowledge of endodontic anatomy , and also more strict supervision on students’ tasks are needed, especially regarding standard root canal treatment on molar teeth.

scholarly journals Physical activity of school children and their parents in Vojvodina

2005 ◽  
Vol 58 (1-2) ◽  
pp. 52-56 ◽  
Author(s):  
Olja Niciforovic-Surkovic ◽  
Erzebet Ac-Nikolic ◽  
Snezana Ukropina ◽  
Vesna Mijatovic-Jovanovic
Keyword(s):  
Physical Activity ◽  
Health Promotion ◽  
Elementary Schools ◽  
Growth And Development ◽  
The Other ◽  
Young Population ◽  
Education And Health ◽  
Significant Difference ◽  
Negative Effect ◽  
Made In

Introduction. Physical activity is very important for normal physical and psychic growth and development. Recent studies in developed and developing countries have shown that today's schoolchildren are spending more and more time in front of the TV and computer, and less and less are engaged in sports. Such lifestyle has a negative effect on health. That is why it is very important for children to develop active habits for life, in order to sustain and promote their health. Material and methods. The study included, a random sample of 210 children from 4 elementary schools and their parents in Vojvodina. Specially designed questionnaires were used. Results and Discussion. The obtained results showed that 75% of schoolchildren are engaged in physical activity, but only 56.5% play sports regularly (every day or 2-3 times a week). There is a significant difference between boys and girls: about 75% of boys and 35% of girls are engaged in physical activity regularly. Similar results have been obtained by other authors (O'Reilly and Shelley, Faucette, Heath etc). Common reasons for physical activity are health, fitness and fun. Pupil's attitude to sports significantly depends on their parent's opinion about physical activity and also on their attitude to recreation in their future life. Parents are not active as their children, only 40% of fathers and 30% of mothers are engaged in various activities regularly. Conclusion. This study showed that schoolchildren are engaged in physical activity, but not enough. On the other hand, their parents are very inactive, although they see the importance of it. Considering the fact that present recreational habits are correlated with the attitude to recreation in the future, an additional effort should be made in health education and health promotion in young population. .

scholarly journals The Importance of MDP Priming, Silica Blasting or Glazing on the Retention Force of Y-TZP Copings to Varying Geometry Tooth Abutments

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 315
Author(s):  
Nathália C. Ramos ◽  
Larissa M.M. Alves ◽  
Gabriela F. Ramos ◽  
Marco Antonio Bottino ◽  
Renata M. Melo ◽  
...  
Keyword(s):  
Tetragonal Zirconia ◽  
Acrylic Resin ◽  
Surface Treatments ◽  
Dihydrogen Phosphate ◽  
Convergence Angle ◽  
Retention Force ◽  
Mechanical Cycling ◽  
Significant Difference ◽  
Zirconia Crowns ◽  
Made In

To evaluate the influence of the convergence angle of tooth preparations and abutments height and several surface treatments for zirconia copings through the tensile retention test. 120 crown preparations were made in Nema G10 with the maxillary first molar anatomy. In total, 60 abutments of 5 mm height were divided into two groups of 6° and 20° convergence angles of tooth preparations, and 60 abutments with a convergence angle of tooth preparations of 12° were divided into groups of 4 and 6 mm heights. Three surface treatments used were MDP-primer (10-Methacryloyloxydecyl dihydrogen phosphate), glazing or silica blasting. The abutments were scanned to make zirconia copings (3Y-TZP–Yttria-Stabilized Tetragonal Zirconia Polycrystals, Vita In-Ceram YZ). After cementation, the mechanical cycling (2 × 106 cycles, 3 Hz, 100 N) was performed to aging. After cycling, the copings were tested in tensile (1 kN load cell; 0.5 mm/s speed). Both abutments support base and copings were embedded in acrylic resin with the aid of a device that maintained the long axis perpendicular to the horizontal plane. Data were analyzed with the two-way ANOVA and Tukey test (95%). ANOVA revealed that the convergence angle influenced the tensile retention (p = 0.0232), but the abutments height showed no statistically significant difference (p = 0.086). The MDP-primer and silica blasting showed higher retention forces in the specimens with height variations. For bonded zirconia crowns, the retention force provided by high convergence angle preparation is critical and cannot be improved by surface treatments. For short and long crown preparations, MDP-based Primers or Silica blasting are advisable to aid restoration longevity.

scholarly journals The The effect of different solutions and thermocycling on the vickers hardness of acrylic resin denture teeth

2018 ◽  
Vol 8 (3) ◽  
pp. 117-122
Author(s):  
Hatice Özdemir ◽  
Zeynep Yeşil Duymuş
Keyword(s):  
Thermal Cycling ◽  
Vickers Hardness ◽  
Artificial Saliva ◽  
Acrylic Resin ◽  
Distilled Water ◽  
Posterior Teeth ◽  
Anterior Teeth ◽  
Denture Teeth ◽  
Occlusal Surfaces ◽  
Disinfectant Solution

Aim: The aim of this study was to evaluate the effect of artificial saliva, disinfectant solution, distile water and thermocycling on Vickers hardness of 4 commercial brands of acrylic resin denture teeth. Methodology: Four different brands of acrylic resin denture teeth (Major Dent, Acry Lux, Acry Rock, Imident Lux) were evaluated. 15 anterior and 15 posterior teeth of each group embedded in autopolymerized acrylic resin.  The occlusal surfaces of posterior teeth and the vestibule surfaces of anterior teeth were flattened by using silicone carbid paper. After polishing, microhardness measurements were repeated three times for each teeth. The teeth were submitted to different conditions: (1) storage in distilled water at 37±2°C for 7 days; (2) storage in artificial saliva at 37±2°C for 30 days and (3) storage in 1 % sodium hypochlorite. After, thermal cycling between 5 and 55 °C for 2500 cycles was made. The microhardness measurements were repeated. Data were analyzed with one-way analysis of variance (ANOVA) and Duncan test ( p<0.05). Results: There was statistical significant differences between initial and final microhardness values of different barnds of acrylic resin denture teet. Anterior teeth showed lower microhardness values than posterior teeth. Conclusion: Storage in different solutions and thermal cycling significantly reduced the Vickers hardness of the acrylic resin denture teeth.

Recolonization of Human Tooth Surfaces by Streptococcus mutans after Suppression by Chlorhexidine Treatment

1987 ◽  
Vol 66 (9) ◽  
pp. 1503-1508 ◽  
Author(s):  
C.G. Emilson ◽  
B. Lindquist ◽  
K. Wennerholm
Keyword(s):  
Streptococcus Mutans ◽  
The Other ◽  
Human Tooth ◽  
Posterior Teeth ◽  
Low Level ◽  
Anterior Teeth ◽  
Tooth Surfaces ◽  
Bacterial Plaque ◽  
Chlorhexidine Gel

In eight subjects who were initially highly colonized with Streptococcus mutans and who used a 1% chlorhexidine gel, the numbers of this organism were suppressed in both plaque and saliva. Bacterial plaque samples were obtained from all tooth surfaces, and the recolonization pattern of S. mutans was studied over a 26-week period. At baseline, 83% of all surfaces harbored S. mutans with buccal surfaces colonized in higher frequency than the others. After chlorhexidine treatment, the proportion of tooth surfaces colonized by S. mutans was reduced to a low level. Re-appearance was slow. S. mutans was first recovered from the most posterior teeth in the mouth, the molar surfaces were recolonized earlier than were those of pre-molars and anterior teeth, and the buccal surfaces were recolonized more readily than were the other tooth surfaces. The data show that there is a specific recolonization pattern of S. mutans after chlorhexidine treatment, and that the re-emergence of S. mutans is most probably due to regrowth of bacteria which have not been eradicated.

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