Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 29
Filter
1.
Acta Odontol Scand ; 80(4): 315-320, 2022 May.
Article in English | MEDLINE | ID: mdl-34892994

ABSTRACT

OBJECTIVE: To evaluate the effect of anterior repositioning splint (ARS) on maximum bite force (MBF) values in patients with disc interference disorders (DID). MATERIAL AND METHODS: Twenty-two patients with disc interference disorders and 22 healthy subjects participated in to study. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I have been used to diagnose DID patients. All patients received ARS therapy for 6 weeks. The MBF measurement was performed with Flexi-Force piezo-resistive sensors for both healthy subjects and patients before and after ARS therapy. RESULTS: A significant difference was recorded by the increase of the mean MBF values after the use of the ARS in the patient with disc derangements (p < .05). CONCLUSIONS: APS therapy is efficient for eliminating pain and increasing MBF of the patients with DID. In addition, the use of FlexiForce sensors may be a practical solution to assess the bite force in the clinical setting.


Subject(s)
Bite Force , Temporomandibular Joint Disorders , Humans , Occlusal Splints , Splints , Temporomandibular Joint Disorders/therapy
2.
Int J Prosthodont ; 32(6): 475-481, 2019.
Article in English | MEDLINE | ID: mdl-31664263

ABSTRACT

PURPOSE: To determine the effectiveness of anterior repositioning splint (ARS) therapy on elimination of temporomandibular joint (TMJ) sounds in patients with internal derangement. MATERIALS AND METHODS: A total of 26 patients with 44 TMJs with internal derangement according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were selected. These patients used an ARS for 6 weeks. The sounds of both the right and left TMJs were recorded with a specifically developed sound recording system before and after ARS therapy. The evaluation of sound was performed using evolutionary spectral analysis on the program MATLAB. Parameters such as sound type, amplitude, duration, and energy were evaluated in a time-frequency analysis. Changes in mean amplitude levels of opening/closing TMJ sounds before therapy and 6 weeks after insertion of splints were compared using paired-samples t test. The level of significance was set at 5%. RESULTS: The patients showed a decrease in the mean amplitude and energy values of opening/closing sounds after 6 weeks of ARS use (P < .05). According to evolutionary spectral analysis, the use of ARS was efficient for 7 of 19 right joints (37%) and 11 of 25 left joints (44%). CONCLUSION: The results suggest that the use of 6-week ARS reduced amplitude and energy parameters of TMJ sounds; however, it did not completely eliminate TMJ sounds.


Subject(s)
Joint Dislocations , Temporomandibular Joint Disorders , Humans , Sound , Splints , Temporomandibular Joint Disc
3.
J Prosthodont Res ; 61(2): 210-216, 2017 Apr.
Article in English | MEDLINE | ID: mdl-27717749

ABSTRACT

PURPOSE: Dual-cure core build-up resins have been developed to take advantages of both self and light-cured resin. The aim of present study was to determine the polymerization characteristics of self and dual-cured modes of dual-cure core build-up composites evaluating degree of conversion (DC) and crosslink density by measurement of glass-transition temperature (Tg) and hardness decrease in ethanol. METHODS: Clearfil Dc Core Automix (CLF) and Grandio Core Dc (GR) core build-up resins were selected. Twelve specimens for both composites were polymerized using quartz-halogen-tungsten light curing unit (QTH) and 12 specimens polymerized chemically. DC was determined by ATR-FTIR spectroscopy. TG/DTA analysis was performed to determine Tg. Microhardness value of specimens was determined by Vickers-tester before and after specimens stored in absolute ethanol for 24h. RESULTS: One-way ANOVA showed no different DC values between dual and self-cured mode of GR and dual-cured CLF composites had higher DC than self-cured mode. Tg and percentage of softening in ethanol values of GR and CLF revealed significant difference between self and dual-cured mode. CONCLUSIONS: In comparison of GR and CLF, DC showed no statistical difference in both curing modes. However, dual and self-cured GR has statistically higher Tg values and lower percentage of softening in ethanol than CLF. Polymerization characteristics of dual-cure core build-up composites have superiority in dual-cured mode than self-cured.


Subject(s)
Acrylic Resins , Chemical Phenomena , Composite Resins , Polyurethanes , Ethanol , Hardness , Light-Curing of Dental Adhesives , Polymerization , Transition Temperature
4.
J Oral Sci ; 58(3): 431-7, 2016.
Article in English | MEDLINE | ID: mdl-27665984

ABSTRACT

The aim of the present study was to compare the effects of some disinfectants, including ethanol extract of propolis (EEP), on the adhesion of Candida albicans to denture base resins. Seventy-two acrylic resin samples were prepared, half of which was polished and the other half was roughened. C. albicans strain ATCC 10231 was incubated on Sabouraud dextrose agar (SDA) at 37°C for 48 h. The adhesion period was completed by keeping the cells in this suspension for 90 min at 37°C. Specimens were then immersed in the following solutions: 1%, 2%, and 5% sodium hypochlorite; 4% chlorhexidine gluconate; and 10% EEP. Quantification of the antifungal activity of the chemical solutions was performed using the colorimetric MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay test. One-way ANOVA and post-hoc Tukey tests were performed to evaluate the effectiveness of chemical agents. Polished and roughened surfaces were compared using independent sample t-test. The mean surface roughness value was 0.35 (±0.04) µm for the polished group and 1.2 (±0.2) µm for the roughened group. The contact angles of both surfaces showed statistically significant difference, and 10% EEP solution exhibited significantly less removal of adherent viable C. albicans cells in both groups. All forms of sodium hypochlorite solutions yielded higher efficiency than 4% chlorhexidine gluconate and EEP solutions (P < 0.05). (J Oral Sci 58, 431-437, 2016).


Subject(s)
Candida albicans/physiology , Cell Adhesion/drug effects , Denture Bases , Disinfectants/pharmacology , Surface Properties
5.
Cranio ; 33(1): 32-7, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25547142

ABSTRACT

OBJECTIVES: The purpose of the present study was to compare craniofacial morphology and bite force of bruxist patients with signs and symptoms of temporomandibular disorders. METHOD: Fourteen subjects with sleep bruxism and 14 healthy subjects participated. The signs and symptoms of the temporomandibular disorders were identified according to the Craniomandibular Index (CMI). Maximum bite force was measured using strain-gage transducers. Lateral cephalometric films were taken, and linear and angular measurements were performed. RESULTS: Bite force between bruxist and non-bruxist females was not significant, whereas males with bruxism revealed higher bite forces. None of the linear and angular measurements differed significantly between bruxist and non-bruxist males. However, higher mandibular corpus length and anterior cranial base length, and lower gonial angle were observed in bruxist females compared to non-bruxist females. Negative correlation between bite force and CMI values was found in both genders. DISCUSSION: Bruxist females had higher CMI values than bruxist males, which could lead to relatively lower bite forces.


Subject(s)
Bite Force , Craniofacial Abnormalities/physiopathology , Sleep Bruxism/physiopathology , Temporomandibular Joint Disorders/physiopathology , Adolescent , Adult , Case-Control Studies , Cephalometry , Craniofacial Abnormalities/diagnostic imaging , Female , Humans , Male , Radiography , Sex Factors , Sleep Bruxism/diagnostic imaging , Temporomandibular Joint Disorders/diagnostic imaging
6.
J Adv Prosthodont ; 6(2): 103-8, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24843394

ABSTRACT

PURPOSE: The occlusal splint has been used for many years as an effective treatment of sleep bruxism. Several methods have been used to evaluate efficiency of the occlusal splints. However, the effect of the occlusal splints on occlusal force has not been clarified sufficiently. The purpose of this study was to evaluate the effect of occlusal splints on maximum occlusal force in patients with sleep bruxism and compare two type of splints that are Bruxogard-soft splint and canine protected hard stabilization splint. MATERIALS AND METHODS: Twelve students with sleep bruxism were participated in the present study. All participants used two different occlusal splints during sleep for 6 weeks. Maximum occlusal force was measured with two miniature strain-gage transducers before, 3 and 6 weeks after insertion of occlusal splints. Clinical examination of temporomandibular disorders was performed for all individuals according to the Craniomandibular Index (CMI) before and 6 weeks after the insertion of splints. The changes in mean occlusal force before, 3 and 6 weeks after insertion of both splints were analysed with paired sample t-test. The Wilcoxon test was used for the comparison of the CMI values before and 6 weeks after the insertion of splints. RESULTS: Participants using stabilization splints showed no statistically significant changes in occlusal force before, 3, and 6 weeks after insertion of splint (P>.05) and participants using Bruxogard-soft splint had statistically significant decreased occlusal force 6 weeks after insertion of splint (P<.05). There was statistically significant improvement in the CMI value of the participants in both of the splint groups (P<.05). CONCLUSION: Participants who used Bruxogard-soft splint showed decreases in occlusal force 6 weeks after insertion of splint. The use of both splints led to a significant reduction in the clinical symptoms.

7.
J Adv Prosthodont ; 6(1): 30-4, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24605203

ABSTRACT

PURPOSE: This study evaluated the adhesion to acrylic resin specimens and biofilm formation capability of Candida albicans strains isolated from HIV positive subjects' oral rinse solutions. MATERIALS AND METHODS: The material tested was a heat-cured acrylic resin (Acron Duo). Using the adhesion and crystal violet assays, 14 oral Candida albicans isolated from HIV-positive subjects and 2 references Candida strains (C. albicans ATCC 90028 and C. albicans ATCC 90128) were compared for their biofilm production and adhesion properties to acrylic surfaces in vitro. RESULTS: There were no significant differences in adhesion (P=.52) and biofilm formation assays (P=.42) by statistical analysis with Mann-Whitney test. CONCLUSION: Denture stomatitis and increased prevalence of candidal carriage in HIV infected patients is unlikely to be related to the biofilm formation and adhesion abilities of C. albicans to acrylic resin materials.

8.
Med. oral patol. oral cir. bucal (Internet) ; 19(1): e1-e7, ene. 2014. tab
Article in English | IBECS | ID: ibc-118245

ABSTRACT

OBJECTIVES: Acromegaly is a metabolic disorder caused by increased growth hormone secretion. As a consequence of acromegaly some typical craniofacial morphology changes appear. This pilot study was conducted to compare the bite force and the characteristic size and shape of the craniofacial components of acromegalic patients with the healthy Turkish individuals. In additon, the correlations between bite force and craniofacial morphology of patients with acromegaly and control individuals were evaluated. Study DESIGN: The maximum bite force of the participants was recorded with strain-gage transducer. Lateral x-ray ray scans were made under standard conditions, in centric occlusion. On cephalograms, the linear and angular measurements was performed. RESULTS: Patients with acromegaly showed increased anterior and posterior total face height, ramus length, width of frontal sinuse, gonial angle and a negative difference between maxillary and mandibular protrusions. In addition, females with acromegaly showed larger lower anterior face height and sella turcica, decreased facial angle, increased mandibular plane angle. The cephalometric measurements, except one did not showed correlation with the bite force in acromegalic patients. In control group, significant correlations were observed between anterior total face height and anterior lower face height, mandibular plane angle and gonial angle. CONCLUSIONS: The greater changes were observed in the mandible. The maximum bite force of patients with acromegaly showed no difference from healthy individuals. The non-significant difference of bite force between healthy participants and acromegalic patients provide important information for dental treatment and prosthetic rehabilitation of acromegalic patients


No disponible


Subject(s)
Humans , Bite Force , Acromegaly/physiopathology , Cephalometry/methods , Prognathism/diagnosis , Case-Control Studies , Turkey
9.
Med Oral Patol Oral Cir Bucal ; 19(1): e1-7, 2014 Jan 01.
Article in English | MEDLINE | ID: mdl-23986010

ABSTRACT

OBJECTIVES: Acromegaly is a metabolic disorder caused by increased growth hormone secretion. As a consequence of acromegaly some typical craniofacial morphology changes appear. This pilot study was conducted to compare the bite force and the characteristic size and shape of the craniofacial components of acromegalic patients with the healthy Turkish individuals. In addition, the correlations between bite force and craniofacial morphology of patients with acromegaly and control individuals were evaluated. STUDY DESIGN: The maximum bite force of the participants was recorded with strain-gage transducer. Lateral x-ray scans were made under standard conditions, in centric occlusion. On cephalograms, the linear and angular measurements was performed. RESULTS: Patients with acromegaly showed increased anterior and posterior total face height, ramus length, width of frontal sinuses, gonial angle and a negative difference between maxillary and mandibular protrusions. In addition, females with acromegaly showed larger lower anterior face height and sella turcica, decreased facial angle, increased mandibular plane angle. The cephalometric measurements, except one did not showed correlation with the bite force in acromegalic patients. In control group, significant correlations were observed between anterior total face height and anterior lower face height, mandibular plane angle and gonial angle. CONCLUSIONS: The greater changes were observed in the mandible. The maximum bite force of patients with acromegaly showed no difference from healthy individuals. The non-significant difference of bite force between healthy participants and acromegalic patients provide important information for dental treatment and prosthetic rehabilitation of acromegalic patients.


Subject(s)
Acromegaly/complications , Acromegaly/physiopathology , Bite Force , Craniofacial Abnormalities/etiology , Craniofacial Abnormalities/physiopathology , Cephalometry , Female , Humans , Male , Pilot Projects
10.
J Adv Prosthodont ; 5(3): 364-8, 2013 Aug.
Article in English | MEDLINE | ID: mdl-24049580

ABSTRACT

The case report describes the occlusal rehabilitation of a male patient with Angle Class III malocclusion and its effect on maximum bite force. The main complaints of patient were masticatory difficulty and poor esthetic. The patient's expectations from the treatment were a good esthetic and function with a less invasive and relatively promptly way. Therefore, increasing of the occlusal vertical dimension (OVD) and then restoring the maxillary and mandibular teeth was chosen by the patient among the treatment options. At the beginning of treatment maximum bite force of patient was measured. Then an occlusal splint was provided to evaluate the adaptation of the patient to the altered OVD. Full mouth rehabilitation with metal ceramic restorations was made. After the completion of full mouth restoration, bite force measurement was repeated and patient exhibited increased maximum bite force. Full mouth restorative treatment in a patient with Class III malocclusion could be an effective treatment approach to resolve esthetic concern and to improve masticatory function related to maximum bite force.

11.
J Appl Biomater Biomech ; 9(2): 118-26, 2011.
Article in English | MEDLINE | ID: mdl-22065389

ABSTRACT

PURPOSE: The purpose of this study was to explore the effects of implant angulation and its possible influence on prosthetic connection as regards implant/tooth strains in a combined implant and natural tooth abutment fixed partial denture. METHODS: A natural tooth was embedded between vertically-aligned and 17° angulated implants in a polymethyl methacrylate acrylic resin model. Three designs (Group 1: tooth and vertically-aligned implant; Group 2: tooth and 17° angulated implant, Group 3: tooth and vertically-aligned implant having a different prosthetic connection to Group 1) of tooth-implant supported prostheses (n=4) were fabricated. Strain gauges were bonded on the prostheses and on the approximal sides of the natural tooth abutment and implants. Once the test fixed partial dentures were seated, a static load of 150 N was applied to each prosthesis. During testing, strain-gauge signals were digitalized by a data acquisition system and this signal was stored and assessed with corresponding software at a sample rate of 10 KHz. RESULTS: The data were then evaluated using Mann-Whitney U and Kruskal Wallis tests at 95% confidence level. Mesiodistal tilting of implants increased peri-implant strains in implant-tooth supported prostheses during torque-tightening and under load. The mode of prosthesis connection may affect strains within the prosthesis and natural tooth abutments, although its impact under static loading conditions seems negligible. CONCLUSIONS: This investigation suggests that mesiodistal tilting of implants may have a biomechanical effect in tooth-implant supported prostheses.


Subject(s)
Dental Implantation , Dental Implants , Materials Testing/methods , Biomechanical Phenomena , Humans , Stress, Mechanical , Weight-Bearing
12.
J Adhes Dent ; 13(6): 579-84, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21734974

ABSTRACT

PURPOSE: This study investigated the peel strength of two different soft liners to a polymethylmethacrylate (PMMA) denture base resin before and after thermocycling. MATERIALS AND METHODS: The silicone-based soft liner materials tested were Molloplast B and Permaflex; the denture base material was a heat-cured acrylic resin, Meliodent. A total of 40 specimens was prepared using rectangular molds with dimensions of 100 x 10 x 2 mm for PMMA and 150 x 10 x 2 mm for soft liners, as described in ASTM-D903-93. For each of the liner materials, 10 specimens were packed against a cured PMMA denture base surface as recommended by the manufacturers. The other 10 specimens were packed against PMMA denture base dough and processed together. In each group, 5 of the specimens were tested directly, while the other 5 were thermocycled in a water bath (5°C to 55°C; 3000 cycles) before testing. Peel testing was performed using an Instron testing machine. RESULTS: The results revealed that peel strength values of the Permaflex specimens prepared according to the manufacturer's recommendations were significantly higher than those of Molloplast B (p < 0.05). However, when packing was done against uncured PMMA dough, the difference between the specimens of two liners was not significant. Thermocycling led to significant decreases in the peel strength of both Permaflex liner specimens packed against cured/uncured PMMA resin surfaces (p < 0.05), whereas this process did not affect the strength of Molloplast B specimens. CONCLUSION: Results indicated that the material Molloplast B was superior to the material Permaflex in terms of peel strength when the specimens were simultaneously polymerized with PMMA and thermocycled.


Subject(s)
Dentures , Resins, Synthetic , Silicones , Hot Temperature , Materials Testing
13.
J Appl Oral Sci ; 19(3): 274-9, 2011.
Article in English | MEDLINE | ID: mdl-21625746

ABSTRACT

OBJECTIVE: Some factors such as gender, age, craniofacial morphology, body structure, occlusal contact patterns may affect the maximum bite force. Thus, the purposes of this study were to determine the mean maximum bite force in individuals with normal occlusion, and to examine the effect of gender, facial dimensions, body mass index (BMI), type of functional occlusion (canine guidance and group function occlusion) and balancing side interferences on it. MATERIAL AND METHODS: Thirty-four individuals aged 19-20 years-old were selected for this study. Maximum bite force was measured with strain-gauge transducers at first molar region. Facial dimensions were defined by standardized frontal photographs as follows: anterior total facial height (ATFH), bizygomathic facial width (BFW) and intergonial width (IGW). BMI was calculated using the equation weight/height². The type of functional occlusion and the balancing side interferences of the subjects were identified by clinical examination. RESULTS: Bite force was found to be significantly higher in men than women (p<0.05). While there was a negative correlation between the bite force and ATFH/BFW, ATFH/IGW ratios in men (p<0.05), women did not show any statistically significant correlation (p>0.05). BMI and bite force correlation was not statistically significant (p>0.05). The average bite force did not differ in subjects with canine guidance or group function occlusion and in the presence of balancing side interferences (p>0.05). CONCLUSIONS: Data suggest that bite force is affected by gender. However, BMI, type of functional occlusion and the presence of balancing side interferences did not exert a meaningful influence on bite force. In addition, transverse facial dimensions showed correlation with bite force in only men.


Subject(s)
Bite Force , Body Mass Index , Face/anatomy & histology , Adult , Dental Occlusion , Female , Humans , Male , Mastication/physiology , Sex Factors , Young Adult
14.
J. appl. oral sci ; 19(3): 274-279, May-June 2011. tab
Article in English | LILACS | ID: lil-588135

ABSTRACT

OBJECTIVE: Some factors such as gender, age, craniofacial morphology, body structure, occlusal contact patterns may affect the maximum bite force. Thus, the purposes of this study were to determine the mean maximum bite force in individuals with normal occlusion, and to examine the effect of gender, facial dimensions, body mass index (BMI), type of functional occlusion (canine guidance and group function occlusion) and balancing side interferences on it. MATERIAL AND METHODS: Thirty-four individuals aged 19-20 years-old were selected for this study. Maximum bite force was measured with strain-gauge transducers at first molar region. Facial dimensions were defined by standardized frontal photographs as follows: anterior total facial height (ATFH), bizygomathic facial width (BFW) and intergonial width (IGW). BMI was calculated using the equation weight/height². The type of functional occlusion and the balancing side interferences of the subjects were identified by clinical examination. RESULTS: Bite force was found to be significantly higher in men than women (p<0.05). While there was a negative correlation between the bite force and ATFH/BFW, ATFH/IGW ratios in men (p<0.05), women did not show any statistically significant correlation (p>0.05). BMI and bite force correlation was not statistically significant (p>0.05). The average bite force did not differ in subjects with canine guidance or group function occlusion and in the presence of balancing side interferences (p>0.05). CONCLUSIONS: Data suggest that bite force is affected by gender. However, BMI, type of functional occlusion and the presence of balancing side interferences did not exert a meaningful influence on bite force. In addition, transverse facial dimensions showed correlation with bite force in only men.


Subject(s)
Adult , Female , Humans , Male , Young Adult , Bite Force , Body Mass Index , Face/anatomy & histology , Dental Occlusion , Mastication/physiology , Sex Factors
15.
J Adhes Dent ; 13(1): 85-92, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21403939

ABSTRACT

PURPOSE: This study compared shear bond strength and type of bond failure between a highly cross-linked tooth and different denture base polymers. MATERIALS AND METHODS: Cross-linked denture teeth were bonded to either a heat-, an auto-, a microwave-polymerized denture base resin or a relatively new injection-molded, microwave-polymerizable polyurethane-based resin. Six experimental groups were established for each of the shear and peel tests. In four of the groups, teeth were used as received and bonded to each of the denture base resins; in the remaining two groups, they were treated with dichloromethane to determine its effect on the bonding with heat or auto-polymerized denture base resins. Bond strength was determined by compressive load applied at 45 degrees on the palatal surface of each tooth until fracture; the type of bond failure was assessed by the peel test. RESULTS: The results showed that heat-cured PMMA groups failed cohesively and demonstrated significantly higher bond strengths than the other resins used. The application of dichloromethane on the ridge lap areas of teeth resulted in a significant improvement of bond strengths in heat- and auto-cured resins. CONCLUSION: Within the limitations of this experimental study, the results suggest that type of denture base material and processing methods may have an influence upon the bond strength between interpenetrating polymer network (IPN) denture teeth and base materials. Treatment of denture teeth with dichloromethane could provide substantial improvement in the bond strength of teeth with heat and auto-cured denture base resins; however, this finding should be validated in further investigations on the long-term effect of such treatment on the bond strength.


Subject(s)
Dental Bonding , Denture Bases , Tooth, Artificial , Acrylic Resins/chemistry , Cross-Linking Reagents , Dental Debonding , Dental Prosthesis Design , Dental Stress Analysis , Light-Curing of Dental Adhesives , Materials Testing , Methylene Chloride/chemistry , Microwaves , Polyurethanes/chemistry , Self-Curing of Dental Resins , Shear Strength
16.
J Adhes Dent ; 13(5): 481-7, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21246070

ABSTRACT

PURPOSE: To determine the effect of resin surface treatment with dissolved maleic anhydride in butanone added into primer on the tensile bond strength between an acrylic denture base resin and a silicone soft liner. MATERIALS AND METHODS: To test tensile bond strength, standard dumbbell-shaped acrylic specimens were prepared. Five experimental groups, including the control, were tested (n = 5). Maleic anhydride solutions prepared in butanone at concentrations of 1%, 5%, 10% or 20% were then mixed with 1 ml of Primo adhesive and the mixtures were applied onto the resin bonding surfaces. Silicone liner material was applied to resin surfaces in the conventional manner. Tensile bond strength of the specimens was measured in a universal testing machine. Fractured surfaces were observed under the scanning electron microscope, and resulting chemical changes with the solutions used were analyzed spectroscopically. RESULTS: The highest bond strength value was obtained for the group treated with 5% maleic anhydride (2.53 ± 0.48 MPa); the lowest value was for the group treated with 20% maleic anhydride (1.59 ± 0.29 MPa). Mixed failure was the dominant type seen in the experimental groups. Spectroscopic analysis showed the interaction of the anhydride carbonyl groups with the Primo primer. CONCLUSION: The treatment of resin surfaces with maleic anhydride added to Primo adhesive effectively increased bond strength between silicone soft liner and denture base resin.


Subject(s)
Dental Bonding , Dental Materials/chemistry , Denture Bases , Denture Liners , Dimethylpolysiloxanes/chemistry , Maleic Anhydrides/chemistry , Polymethyl Methacrylate/chemistry , Silicone Elastomers/chemistry , Butanones/chemistry , Dental Cements/chemistry , Dental Stress Analysis/instrumentation , Humans , Materials Testing , Microscopy, Electron, Scanning , Solvents/chemistry , Spectroscopy, Fourier Transform Infrared , Stress, Mechanical , Surface Properties , Tensile Strength
17.
Eur J Dent ; 4(2): 223-32, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20396457

ABSTRACT

Maximum voluntary bite force is an indicator of the functional state of the masticatory system and the level of maximum bite force results from the combined action of the jaw elevator muscles modified by jaw biomechanics and reflex mechanisms. The measurement of bite force can provide useful data for the evaluation of jaw muscle function and activity. It is also an adjunctive value in assessing the performance of dentures. Technological advances in signal detection and processing have improved the quality of the information extracted from bite force measurements. However, these measurements are difficult and the reliability of the result depends on a number of factors, such as presence of pain and temporomandibular disorders, gender, age, cranio-facial morphology, and occlusal factors. In addition to these physiological factors, recording devices and techniques are important factors in bite force measurement. Therefore, one should be careful when comparing the bite force values reported in the research.

18.
Gerodontology ; 27(4): 283-91, 2010 Dec.
Article in English | MEDLINE | ID: mdl-19804557

ABSTRACT

OBJECTIVES: Microorganisms may colonise polysiloxane soft liners leading to bio-deterioration. The aim of this study was to investigate in vitro adhesion and in vivo biofilm formation of Candida species on polysiloxane surfaces. METHODS: The materials used in this study were Molloplast B, GC Reline soft, Mollosil Plus, Silagum Comfort and Palapress Vario. The in vitro retention of clinical isolates of Candida albicans to the relining and denture-base materials by microscopic (scanning electron microscopy, SEM), conventional culturing methods and antimicrobial properties of these materials were studied. Candida found on materials and mucosa following long-term use were identified and quantified, and biofilms covering the surfaces were investigated by SEM. RESULTS: There was a significant decrease in the number of cells attached in vitro to saliva-coated surfaces compared with non-treated surfaces. An oral Candida carriage of 78% was found. Candida albicans, C. glabrata, C. intermedia and C. tropicalis were identified. In vivo biofilm formation on the liners appeared as massive colonisation by microorganisms. CONCLUSIONS: The results of the in vitro experiments suggest that salivary film influences early colonisation of different C. albicans strains. The film layer also minimises the differences among different strains. The Candida carriage of these patients was similar to denture-wearing patients without soft liners.


Subject(s)
Biocompatible Materials/chemistry , Biofilms/growth & development , Candida/physiology , Denture Liners/microbiology , Siloxanes/chemistry , Acrylic Resins/chemistry , Antifungal Agents/chemistry , Candida/classification , Candida albicans/isolation & purification , Candida albicans/physiology , Candida glabrata/isolation & purification , Candida glabrata/physiology , Candida tropicalis/isolation & purification , Candida tropicalis/physiology , Colony Count, Microbial , Dental Pellicle/microbiology , Denture Bases/microbiology , Denture Rebasing , Dimethylpolysiloxanes/chemistry , Female , Humans , Hydrophobic and Hydrophilic Interactions , Immunodiffusion , Male , Materials Testing , Microbiological Phenomena , Microscopy, Electron, Scanning , Middle Aged , Mycology/methods , Silicone Elastomers/chemistry , Time Factors
19.
Dent Mater J ; 28(3): 253-60, 2009 May.
Article in English | MEDLINE | ID: mdl-19662722

ABSTRACT

This study investigated temperature rises caused by different light curing units (LCUs) in dentin of different thicknesses. The different LCUs tested in this study were namely: quartz-tungsten-halogen (QTH) (Heliolux DLX) LCU, plasma arc (PAC) (Apollo 95E Elite) LCU, and light emitting diode (LED) (Mini LED) in standard curing mode as well as pulse and soft-start modes. One hundred and forty dentin disks of 0.5, 1, 1.5, and 2 mm thickness were prepared from mandibular molars (n=7). Temperatures were recorded using a L-type thermocouple in direct contact with the light guide tip. For all curing units/modes, dentin thickness was inversely proportional to temperature rise and that QTH light gave significantly higher values compared to PAC and LED in all the test conditions. The highest temperature rise was observed under 0.5-mm-thick dentin disk with QTH, whereas the lowest temperature rise was registered with LED light in pulse mode under 2-mm-thick dentin.


Subject(s)
Body Temperature/radiation effects , Curing Lights, Dental/classification , Dentin/radiation effects , Dentin/anatomy & histology , Equipment Design , Humans , Molar , Radiation Dosage , Thermometers , Time Factors
20.
J Contemp Dent Pract ; 10(3): 74-80, 2009 May 01.
Article in English | MEDLINE | ID: mdl-19430629

ABSTRACT

AIM: The aim of this report is to describe the relationship of some salivary parameters to dental erosion resulting from excessive citric acid consumption and present a description of a prosthetic approach used to restore the damaged dentition of a patient with severe erosion. BACKGROUND: The high consumption of dietary sources of acids can lead to erosion or the excessive wear of dental hard tissues. Erosion may be modified by salivary parameters such as flow rate, pH, and buffering capacity. Porcelain-fused-to-metal (PFM) restorations and composite resin veneers can be used successfully to restore impaired esthetics and eliminate tooth hypersensitivity in such cases. RESULTS: A 37-year-old woman with a history of excessive lemon consumption presented with a complaint of tooth hypersensitivity and the poor appearance of her dentition due to erosion. Stimulated and unstimulated salivary samples of the patient were evaluated for flow rate, pH, and buffering capacity before and after treatment. The pre-treatment values were found to be higher than post-treatment values. Stimulated samples showed an increase of salivary flow rate, pH, and buffering capacity. The measured parameters put forth the defensive potential of saliva against the acidic diet, and the salivary flow rate and buffering capacity decreased after reducing acidic consumption. The excessively eroded teeth were restored using PFM restorations whereas the superficially eroded teeth were restored with composite resins. SUMMARY: The introduction of acidic foods, beverages, or other agents can exceed the natural buffering capacity of saliva. The result is a lowering of the pH of the oral environment which can lead to erosion of enamel and dentin. Loss of tooth structure due to erosion can compromise the esthetics of the dentition and lead to hypersensitivity of the teeth. Teeth damaged by erosion can be successfully restored by composite resin or porcelain restorations and esthetics and function of dentition can be improved. CLINICAL SIGNIFICANCE: This report is a profound example of how the over consumption of acidic agents affect not only dental tissues but also the chemical balance of the oral environment as well as the oral habitat.


Subject(s)
Dental Restoration, Permanent/methods , Saliva/physiology , Tooth Erosion/etiology , Tooth Erosion/rehabilitation , Adult , Buffers , Citric Acid/adverse effects , Citrus/adverse effects , Composite Resins , Feeding Behavior , Female , Humans , Hydrogen-Ion Concentration , Metal Ceramic Alloys , Saliva/chemistry , Secretory Rate , Sucking Behavior
SELECTION OF CITATIONS
SEARCH DETAIL
...