Biomedical subjects

P Rammelsberg

Publications and source records attributed to P Rammelsberg.

At least 19 recordsLinked to original sources

PubMed2005

[Oral health-related quality of life in elderly].

PURPOSE: The aim of this study was to describe the oral health related quality of life (OHRQoL) of institutionalized elderly. MATERIAL: 159 elderly were randomly selected for this, study ranging in age from 61 to 98 (mean age 82.8; 19.1% male, 80.9% female). For measuring the OHRQoL the Oral Health Impact Profile (OHIP) was used. Additionally, a dental status was evaluated. RESULTS: 15% of the subjects had only natural teeth or fixed dentures, 80% removable dentures and 15% no dentures at all. OHIP-mean reached 33+/-25 points, between 0 and 112. The subcategory "functional limitation" showed the highest impairment (6.3%). The items with the highest impairment on OHRQoL in the different subcategories were: dentures not fitting properly, uncomfortable dentures, self-conscious due to teeth, avoid eating some foods, felt depressed, avoid going out and general health worsened. CONCLUSIONS: The OHIP summary score represents an overview of OHRQoL and answers detailed questions with the help of the single items. In institutionalized elderly many items showed impairment, especially in items concerning the prosthetic restorations. This demonstrates the need for dental aftercare and not only dental interventions for acute pain. Establishing aftercare and prophylaxis could increase the OHRQoL and subsequently the overall well-being.

Aged↗

PubMed2005

The failure rate of adhesively retained composite core build-ups in comparison with metal-added glass ionomer core build-ups.

OBJECTIVES: The purpose of this study was to evaluate the clinical performance of two adhesively retained composite core materials and compare them with a metal-added glass ionomer. The main objective evaluated was total or partial loss of build-ups during the treatment prior to crown cementation. METHODS: In 187 patients, 315 vital and non-vital teeth were built up after randomisation with either Rebilda D (RD), Rebilda SC (RSC) or Ketac Silver Aplicap (KSA). The composites were applied in the total-etch-technique with the corresponding dentin bonding agent. The metal-added glass ionomer was used with a conditioner. One group of patients was treated by experienced dentists, the other by dental students, in order to evaluate the effects of different levels of experience. Data were analysed using Mann-Whitney-U-Test and binomial logistic regression. RESULTS: The early failure rate (partial or total loss) of core build-ups before crown cementation was significantly higher for KSA (28.8%), as compared to RSC (15.3%, p=0.037) and RD (15%, p=0.025). Most failures were observed during the removal of the temporary crowns. The rate of replacements was between 3.0 (RD/dentists) and 20.4% (KSA/students). Furthermore, we found that build-ups made by students had a significantly higher risk of loss than those made by dentists (p=0.028). CONCLUSIONS: Adhesively retained self-curing composites show a better clinical short-term performance and can be recommended as core build-up materials.

Adhesives↗

PubMed2005

The prevalence of signs and symptoms of temporomandibular disorders in very old subjects.

Previous studies on the prevalence of signs of temporomandibular disorders (TMD) in elderly people have used non-standardized and invalidated examination protocols. The prevalence of the different signs of TMD in this group is therefore still unclear. The aim of this study was to evaluate the prevalence of signs of TMD in subjects of advanced aged, using a standardized and validated examination protocol. Additionally, young subjects were examined as a control group. Fifty-eight old peoples' home inhabitants and 44 young subjects were examined using a standardized and validated examination protocol. Differences between the groups were assessed using Mann-Whitney U-test or t-test. Geriatric subjects more often exhibited objective symptoms of TMD (38% exhibited joint sounds on opening), but rarely suffered from pain (pain at rest: 0%, joint pain: 0%, muscle pain: 12%). In contrast, young subjects rarely exhibited objective symptoms (joint sounds: 7%), but suffered more frequently from pain (facial: 7%, joint pain: 16%, muscle pain: 25%). The mandibular range of motion was higher in young subjects. Differences between the groups with respect to joint sounds, muscular palpation pain and mandibular range of motion were significant. Although older subjects more frequently exhibited objective signs (joint sounds) of TMD, they rarely suffered from pain. In contrast, younger subjects rarely exhibited objective TMD signs but more frequently suffered from subjective signs (muscular pain on palpation) and facial pain.

Adult↗

PubMed2004

The effect of quality of temporomandibular joint MR images on interrater agreement.

OBJECTIVES: Effects of calibration on interrater agreement in evaluating magnetic resonance (MR) images of the temporomandibular joint (TMJ) have already been examined. The objectives of the present study were to assess to what extent the quality of MR images of the TMJ influences interrater agreement and to evaluate interrater agreement with respect to image quality assessment. METHODS: Two non-calibrated medical radiologists and two general dentists evaluated sagittal images of 100 TMJs for both a rating of the image quality and the performance of five diagnostic tasks. The agreement between these raters with respect to the diagnoses was evaluated. Additionally, two additional raters, calibrated during a 5 h training including the evaluation of 70 MR images, also evaluated the diagnostic aspects and the image quality, on the basis of objective criteria. The agreement between the subjective diagnoses of the non-calibrated raters and the objective diagnoses of the calibrated raters was evaluated. Afterwards, the subjective and the objective quality assessments were compared using kappa statistics. RESULTS: When good quality images were evaluated, higher kappa values were obtained for all diagnostic categories by the non-calibrated raters (mean Deltak for making diagnoses >0.1). This finding was confirmed by the value obtained for the agreement between the non-calibrated and the calibrated raters. The non-calibrated raters were in good agreement (k=0.67, standard error +/-0.09) with the calibrated raters for assessment of image quality. CONCLUSION: The present study shows that it is possible even without calibration to obtain a better interrater agreement when higher quality MR images of the TMJ are evaluated.

Adult↗

PubMed2001

[Diagnostic imaging of the normal anatomy of the temporomandibular joint].

Computed tomography (CT) and magnetic resonance imaging (MRI) are well established imaging modalities to examine the TMJ. MRI is superior to CT in delineating the morphological architecture of the TMJ, not only in cases of normal anatomy, inflammation or tumors, but also if dysfunction of the TMJ is present. This review article presents anatomy as well as imaging strategies of the TMJ.

Humans↗

PubMed2001

Morphology of the mandibular fossa and inclination of the articular eminence in patients with internal derangement and in symptom-free volunteers.

OBJECTIVE: The purpose of this study was to evaluate temporomandibular joint morphology and to compare possible structural variations in the temporomandibular joint anatomy of symptomatic anterior disk displacement patients with possible structural variations in the temporomandibular joint anatomy of symptom-free volunteers. STUDY DESIGN: Fifty-six symptomatic patients and 25 symptom-free volunteers were included in this study. All subjects had bilateral high-resolution magnetic resonance imaging scans performed in the sagittal (closed and open) positions. Disk positions were evaluated with these images, and the patients were accordingly classified into 4 diagnostic groups. The angulation between the Frankfort horizontal plane and the posterior slope of the articular eminence, as well as the width and depth of the glenoid fossa and the articular tuberculum, were automatically measured with the aid of a computer. RESULTS: The Mann-Whitney U test demonstrated significant differences in the angular and linear values obtained in disk displacement with reduction patients in comparison with the values obtained in patients with disk displacement without reduction and in symptom-free volunteers. CONCLUSION: It is proposed that a steeper posterior slope and higher tuberculum articulaire are predisposing factors for the development of disk displacement with reduction. Flattening of the eminence may progress in time, leading to the onset of disk displacement without reduction.

Adult↗

PubMed2001

Axial condyle morphology and horizontal condylar angle in patients with internal derangement compared to asymptomatic volunteers.

The purpose of this study was to evaluate the possible structural variations of axial condyle morphology and horizontal condylar angle between patients with internal derangement and asymptomatic volunteers. Forty-five symptomatic patients and 31 asymptomatic volunteers (AV) were included in this study. All subjects had bilateral high-resolution magnetic resonance imaging scans. Axial condyle morphology was evaluated using these images and classified into four diagnostic groups: convex, flat, and concave anterior surfaces, and tapered form. The angulation between the condylar long axis and the transversal plane was then measured. A Wilcoxon-Whitney-Mann-U-test demonstrated no significant differences in the horizontal angulation of the patients with disk displacement with reduction (DDR) (24.35+/-9.31) as compared to patients with displacement without reduction (DDN) (25.61+/-10.11) and asymptomatic volunteers (25.68+/-9.31) (AV). Eighty percent of the flat type condyles and 73.3% of the tapered type condyles belonged to the symptomatic patients with disk displacement with reduction (DDR) and without reduction (DDN). Chi-square test demonstrated significant differences between the diagnostic groups of condyle types (p<0.01). A comparison of the angular difference of right and left joints of asymptomatic volunteers and patients using the Wilcoxon-Whitney-Mann-U test showed that the results of the asymptomatic volunteers were significantly lower (p = 0.05). The conclusion that an increase in the horizontal condylar angle is a predisposing factor for the development of internal derangement or that the derangement develops during the prognosis of the disorder could not be clearly stated based on the results of this study. It is proposed that the difference between condyle morphology in patients with disk displacement and asymptomatic volunteers may be a result of the remodeling or degeneration caused by the disorder.

Bone Remodeling↗

PubMed2000

Magnetic resonance imaging-based joint space measurements in temporomandibular joints with disk displacements and in controls.

OBJECTIVE: Previous studies have discussed a posterior displacement of the condyle as a possible risk factor for the development of disk displacements (DDs) of the temporomandibular joint (TMJ). The objective of this study was to compare the posterior and anterior joint spaces in healthy TMJs with those of patients who present different forms of DDs. STUDY DESIGN: The anterior and posterior joint spaces from 58 patients with unilateral or bilateral DD with reduction (DDR) or without reduction (DDNR) and from 30 healthy volunteers were measured with 3 sagittal magnetic resonance images (MRIs) from each TMJ in the maximum intercuspid position. RESULTS: Measurements of anterior and posterior joint spaces showed a good interexaminer reproducibility (rank correlation coefficients ranging from 0.88 to 0.95). Patients with bilateral DDR demonstrated a significantly more posterior position of the condyle, as compared with controls and patients with bilateral DDNR. DDNR presented a significant reduction of the anterior and the posterior joint spaces, leading to a mean concentric position of the condyle. Patients with unilateral DDR or DDNR demonstrated a greater variability of anterior and posterior joint spaces, compared with patients with a bilaterally identical type of DD. CONCLUSIONS: The data of this MRI-based clinical study indicate that different stages of disk displacements are associated with significant changes of condylar position. The variation of anterior and posterior joint spaces was influenced by the diagnosis of the contralateral joint.

Adolescent↗

PubMed2000

Fracture resistance of posterior metal-free polymer crowns.

STATEMENT OF PROBLEM: Improved mechanical properties of contemporary composites has resulted in the extended use of composites for the restoration of posterior teeth. Although the indication of polymers was extended to metal-free individual crowns, the influence of tooth preparation design and cementation methods on the stability of these artificial crowns remains unknown. PURPOSE: This in vitro study evaluated the effect of axial tooth preparation design, occlusal dimension, and cementation technique on the fracture resistance of metal-free posterior Artglass crowns. MATERIAL AND METHODS: Seventy-two extracted human third molars, assigned to experimental groups by size, received standardized tooth preparation. Axial tooth preparation included an invasive approach with 1-mm deep shoulder and a less invasive 0.5-mm chamfer preparation, whereas occlusal reduction was either 0.5 mm or 1.3 mm. Artglass crowns that restored the original tooth contour were cemented with 3 cements: zinc phosphate cement (ZnP), glass ionomer cement (GIC), or a resinous cement in combination with a dentinal bonding agent. After 10,000 thermal cycles between 5 degrees C and 55 degrees C, artificial crowns were vertically loaded until compression to failure. Significant differences of fracture loads between experimental groups were assessed by paired Mann-Whitney U tests. RESULTS: Minimal fracture resistance for all combinations excluded 500 N. However, 9 of 24 Artglass crowns cemented with ZnP loosened after thermocycling. Adhesive cementation resulted in a significantly greater fracture resistance compared with GIC and ZnP (P=.02). Increased occlusal thickness (0.5 to 1.3 mm) resulted in greater stability, whereas a 1-mm deep shoulder tooth preparation did not improve durability compared with a 0.5-mm chamfer finishing line. CONCLUSION: A minimally invasive 0.5-mm axial chamfer tooth preparation combined with sufficient occlusal reduction and adhesive cementation recorded the greatest stability for posterior metal-free Artglass crowns.

Cementation↗

PubMed1998

Adhesive-fixed partial dentures in anterior and posterior areas. Results of an on-going prospective study begun in 1985.

Within the framework of an on-going prospective clinical study begun in 1985, 120 adhesive-fixed partial dentures (AFPD) continued to be examined. The manufacture and the fitting of the AFPDs were carried out following a standard procedure. The preparation technique and the metal framework conditioning (silica-coating, sand-blasting and electrochemical etching) has varied throughout the duration of the study. Using Kaplan-Meier analysis, the survival rate was determined and an analysis of risk with regard to location factors (anterior, posterior; maxilla, mandible), conditioning and preparation techniques (retentive/non-retentive) was determined using the Cox regression model. The location of the AFPD had no influence on the survival rate. The survival time was determined mainly by the preparation technique. Strict preparation of seating grooves and pin holes made a 95% survival rate possible after 10 years (Kaplan-Meier estimation). Without retention, the risk of failure increased by a factor of 3.7.

Adolescent↗

PubMed1997

Variability of disk position in asymptomatic volunteers and patients with internal derangements of the TMJ.

This study determined the variability of temporomandibular joint (TMJ) disk position in medial, central, and lateral aspects of the joint using magnetic resonance imaging (MRI). Subjects had clinical evidence of reciprocal TMJ clicking (N = 123) or restricted mandibular motion (N = 52). Eighty-nine asymptomatic volunteers provided a control group. Disk position was quantified on MRI by measuring the angle formed by a line through the middle of the condyle and perpendicular to the Frankfort plane and a line through the same midpoint of the condyle and tangential to the posterior-most aspect of the disk. The disk position in asymptomatic TMJs varied considerably with a tendency toward farther anterior placement in more lateral images. In 47 TMJs from a total of 52 TMJ5 (90%), restricted mobility was associated with anterior disk displacement (ADD) without reduction. The disk position demonstrated a mean displacement of 77 degrees without significant differences at the medial and lateral aspects of the condyle. One hundred TMJs from a total of 123 TMJs (81%) with reciprocal clicking demonstrated ADD with reduction. Tomograms revealed larger lateral displacements or rotational displacements in these joints, whereas medial images frequently showed similar ranges of disk positions as compared with asymptomatic TMJs. The results suggest that disk positions of up to +15 degrees on medial tomograms and +30 degrees on lateral tomograms should be regarded as normal variations. Furthermore, multisection analysis of all parasagittal images improved the separation between disk displacement and asymptomatic TMJs.

Adolescent↗

PubMed1996

Evaluation of diagnostic criteria from computerized axiography to detect internal derangements of the TMJ.

Objective of this study was to evaluate the diagnostic value of 3-D computed axiography to detect anterior disk displacements (ADD) of the TMJ. 65 patients with MRI confirmed ADD with reduction and 27 patients with ADD without reduction were examined by 3-D computed axiography. 44 healthy volunteers with normal disk position and joint function served as controls. A descriptive analysis of the axiographic opening/closing cycle revealed significantly higher rates of abrupt deviations, accelerations/decelerations, and crossings for ADD with reduction compared to healthy volunteers. A new axiographic index reduced the number of false positive to 10% and false negative to 14% of the diagnosis. ADD without reduction was characterized by significantly shorter opening curves. The optimum split point at 11 mm, resulted in 10% false positive and 20% false negative diagnosis. However, the diagnostic value of computed axiography was reduced by the significant influence of the clicking or limited joint on the contralateral TMJ.

Adolescent↗

PubMed1996

All-ceramic resin-bonded bridges. A 3-dimensional finite-element analysis study.

Resin-bonded fixed partial dentures (FPD) with a metal framework have some disadvantages: a grey shimmer of the metal wings through the abutment teeth, a higher corrosion rate, and an allergenic potential of the non-precious alloys used. The Al2O3 ceramic In-Ceram seems to be strong enough to serve as a framework for resinbonded all-ceramic FPDs. Because of the fact that ceramic wings often don't have enough inter-occlusal space, a new preparation design was developed. The objective of this study was to determine the influence of load orientation (45 degrees and 60 degrees) and the design of the interproximal connector on the stress distribution in the bridges. A 3-dimensional finite-element model was developed to simulate the anatomical situation. The biting force was assumed as 250 N and oriented in oro-buccal direction. The loading-point was palatal 1.5 mm beneath the incisal edge. It was found that stress generally increased with an angle of the biting force of 60 degrees. A small interdental connector (3 mm height) and/or strong interdental separation resulted in stresses of up to 455 MPa (45 degrees) or 534 MPa (60 degrees). Less separation with rounded edges and a higher connector (4 mm) reduced the stress to 122 MPa (45 degrees) and 143 MPa (60 degrees). Due to an average tensile strength of In-Ceram at 340-400 MPa, an all-ceramic resin-bonded FPD may only be recommended if the height of the connector could be minimum 4 mm. Rounded edges and little interdental separation are significant for stress reduction.

Allergens↗

PubMed1996

A new design for all-ceramic resin-bonded fixed partial dentures.

After 7 years of clinical experience, the alumina ceramic, In-Ceram, can be regarded as a well-proven material for all-ceramic crowns. Because of its high strength, this material can also be used for small all-ceramic fixed partial dentures. First attempts at using this material for resin-bonded prostheses revealed a high failure rate. The aim of this article is to present a new preparation design for all-ceramic resin-bonded fixed partial dentures that allows fabrication of highly esthetic and also tooth-saving adhesive prostheses. Clinical results over a period of 4 years revealed that they are strong enough to replace anterior teeth. Nevertheless, positive long-term clinical results are necessary before a general recommendation can be given for this kind of prosthesis.

Aluminum Oxide↗

PubMed1993

Clinical factors affecting adhesive fixed partial dentures: a 6-year study.

One hundred forty-one adhesive fixed partial dentures were placed under controlled conditions for a 6-year longitudinal study. The influence of location (anterior/posterior, maxilla/mandible), tooth preparation techniques (retentive/less invasive), and four different methods of metal conditioning (sandblasting/electrolytic etching and/or pyrolytic/tribochemical silane coating) on the survival rate was investigated. Failures (23 of 24) were caused by loss of adhesion at the metal-cement interface. The retentive tooth preparation reduced the risk of failure to almost one twentieth, but the intraoral location did not influence survival time. The effect of silane-coating on longevity was extremely positive and was not reflected by successful retainers.

Chi-Square Distribution↗

PubMed1991

[Clinical comparison of bonded bridges as a function of preparation and metal conditioning. Statistical analysis of failures].

A total of 107 bonded bridges could be re-evaluated after a mean period of 2.3 years and a maximum of 5 years. The preparation of mechanical retentive aids, such as grooves and bores resulted in a significant reduction of failure rates after one year. Electrolytical etching or silicoating of the CoCr restorations failed to have any effect on the failure rates of those bridges that were provided with adequate mechanical retention.

Adolescent↗

PubMed1991

[Success of implantation depending on the type of prosthetic superstructure].

53 patients with 120 endosseous implants could be re-evaluated after a mean period of 2.7 years (maximum 5 years). Using casts from the upper with transfer posts and lower jaw, we measured the deviation of the implant axes from their ideal direction and localisation. Furthermore, we tried to find out, whether an unfavourable localisation compromised the prognosis of osseointegrated implants. Ideal, axial load by the prosthetic construction was often impossible because of unfavourable localisation of the implants. In a rank correlation analysis we found a significant influence of unfavourable localisation on prognosis in the group of hinge bars. Further weak correlations were revealed between loss of attachment and gingiva index which in turn was correlated with the plaque index.

Adolescent↗

PubMed1990

[Differential diagnosis of reciprocal joint clicking using electronic axiography (SAS)].

25 patients with reciprocal clicking in one or both temporomandibular joints were examined clinically and with an electronic axiographic system (SAS-System). Studying the direction of the sudden change of the condylar path during clicking, we established a tentative differential diagnosis of "centric anterior dislocations" of the disc and "eccentric posterior dislocations". Interpreting the axiographic pathways we found an eccentric posterior dislocation of the disc in 20 TMJs. But in at least 11 cases, which could be re-evaluated by magnetic resonance tomography (CMR), the diagnosis "eccentric posterior dislocation" was false. As we found several variations of anterior dislocations with a cranial and lateral deviation of the condylar path during opening clicking, the diagnosis of "eccentric disc dislocations" established by axiography was not reliable.

Adolescent↗