Prosthodontic treatment can improve the ingestible food profile in Japanese adult outpatients.

PURPOSE: To investigate the effect of prosthodontic treatment on the ingestible food profile in adult Japanese outpatients, and to identify the related risk factors that can deteriorate the profile. METHODS: The participants were 277 outpatients who visited university-based specialty clinics in Japan for prosthodontic treatment. The demographic data, number of present teeth assessed via intraoral examination, and oral health-related quality of life assessed by the total Oral Health Impact Profile (OHIP-J54) scores of all participants were recorded before treatment. Ingestible food profile score (IFS) was recorded using a validated food intake questionnaire. Eligible participants who answered the questionnaire before and after treatment were categorized into five groups based on the prosthodontic treatments they received (i.e., crowns, bridges, removable partial dentures, removable complete dentures, and removable complete and partial dentures). RESULTS: Multivariate analysis of covariance revealed a statistically significant main effect of prosthodontic intervention (time course: before and after treatment) on mean IFS (P=0.035, F=4.526), even after adjusting for covariates (age, number of present teeth, and treatment modality). Multiple linear regression analysis revealed that the low number of present teeth (r=0.427, P<0.001) and a high OHIP-J54 total score (r=-0.519, P<0.001) of the patients at the baseline were significantly associated with their baseline IFSs, even after adjusting for confounding variables. CONCLUSIONS: The findings of this multicenter follow-up study indicate the importance of prosthodontic rehabilitation in improving patients' ingestible food profiles.

A multi-centered epidemiological study evaluating the validity of the treatment difficulty indices developed by the Japan Prosthodontic Society.

PURPOSE: The Japan Prosthodontic Society developed a multi-axis assessment protocol to evaluate the complex variations in patients who need prosthodontic care, and to classify the level of treatment difficulty. A previous report found the protocol to be sufficiently reliable. The purpose of this multi-center cohort study was to evaluate the validity of this multi-axis assessment protocol. METHODS: The treatment difficulty was evaluated using the multi-axis assessment protocol before starting prosthodontic treatment. The time required for active prosthodontic treatment, medical resources such as treatment cost, and changes in the oral health-related QOL before and after treatment, were evaluated after treatment completion. The construct validity of this protocol was assessed by the correlation between the dentist's pre-operative subjective assessment of the treatment difficulty, and the level of difficulty determined by this protocol. The predictive validity was assessed estimating the correlations between a "comprehensive level of treatment difficulty" based on the four axes of this protocol and total treatment cost, total treatment time, and changes in the oral health-related QOL before and after treatment. RESULTS: The construct validity of this protocol was well documented except for psychological assessment. Regarding the predictive validity, the comprehensive level of treatment difficulty assessed before treatment was significantly correlated with the three surrogate endpoints known to be related to the treatment difficulty (total treatment cost, treatment time, and improvement in the oral health-related QOL). To further clarify the validity of the protocol according to patients' oral condition, a subgroup analysis by defects was performed. Analyses revealed that treatment difficulty assessment before treatment was significantly related to one or two surrogate endpoints in the fully edentulous patients and the partially edentulous patients. No significant relationship was observed in the patients with mixture of full/partial edentulism and the patients with teeth problems, possibly due to the small sample size in these groups. CONCLUSION: This study revealed that the multi-axis assessment protocol was sufficiently valid to predict the level of treatment difficulty in prosthodontic care in patients with fully edentulous defects and with partially edentulous defects.

Reliability and validity of the patient disability-oriented diagnostic nomenclature system for prosthetic dentistry.

PURPOSE: The Japan Prosthodontic Society (JPS) has proposed a new diagnostic nomenclature system (DNS), based on pathogenesis and etiology, to facilitate and improve prosthodontic treatment. This system specifies patient disability and the causative factor (i.e. "B (disability) caused by A (causative factor)"). The purpose of this study was to examine the reliability and validity of this DNS. STUDY SELECTION: The JPS Clinical Guideline Committee assessed mock patient charts and formulated disease names using the new DNS. Fifty validators, comprising prosthodontic specialists and dental residents, made diagnoses using the same patient charts. Reliability was evaluated as the consistency of the disease names among the validators, and validity was evaluated using the concordance rate of the disease names with the reference disease names. RESULTS: Krippendorff's α was 0.378 among all validators, 0.370 among prosthodontic specialists, and 0.401 among dental hospital residents. Krippendorff's α for 10 validators (3 specialists and 7 residents) with higher concordance rates was 0.524. Two validators (1 specialist and 1 resident) with the highest concordance rates had a Krippendorff's α of 0.648. Common disease names had higher concordance rates, while uncommon disease names showed lower concordance rates. These rates did not show correlation with clinical experience of the validator or time taken to devise the disease name. CONCLUSIONS: High reliability was not found among all validators; however, validators with higher concordance rates showed better reliability. Furthermore, common disease names had higher concordance rates. These findings indicate that the new DNS for prosthodontic dentistry exhibits clinically acceptable reliability and validity.

Physicochemical state of the nanotopographic surface of commercially pure titanium following anodization-hydrothermal treatment reveals significantly improved hydrophilicity and surface energy profiles.

A method of coating commercially pure titanium (cpTi) implants with a highly crystalline, thin hydroxyapatite (HA) layer using discharge anodic oxidation followed by hydrothermal treatment (Spark discharged Anodic oxidation treatment ; SA-treated cpTi) has been reported for use in clinical dentistry. We hypothesized that a thin HA layer with high crystallinity and nanostructured anodic titanium oxide film on such SA-treated cpTi implant surfaces might be a crucial function of their surface-specific potential energy. To test this, we analyzed anodic oxide (AO) cpTi and SA-treated cpTi disks by SEM and AFM. Contact angles and surface free energy of each disk surface was measured using FAMAS software. High-magnification SEM and AFM revealed the nanotopographic structure of the anodic titanium oxide film on SA-treated cpTi; however, this was not observed on the AO cpTi surface. The contact angle and surface free energy measurements were also significantly different between AO cpTi and SA-treated cpTi surfaces (Tukey's, P<0.05). These data indicated that the change of physicochemical properties of an anodic titanium oxide film with HA crystals on an SA-treated cpTi surface may play a key role in the phenomenon of osteoconduction during the process of osseointegration.

A multi-centered epidemiological study evaluating the reliability of the treatment difficulty indices developed by the Japan Prosthodontic Society.

BACKGROUND: The diagnostic assessment of the level of difficulty in treating patients who need prosthodontic care is useful to establish a medico-economically efficient system with primary care dentists and prosthodontic specialists. MATERIALS AND METHODS: A multi-axis assessment protocol was established using the newly established treatment difficulty indices. The protocol contains Axis I: oral physiological conditions (e.g., teeth damage and/or missing teeth); Axis II: general health and sociological conditions (e.g., medical disorders); Axis III: oral health-related quality of life (OHRQOL; e.g., oral health impact profile: OHIP); and Axis IV: psychological health (e.g., mood, anxiety, somatoform disorders). A preliminary study on the test-retest consistency of the protocol was conducted to check the levels of reliability of the indices prior to a large-scale, multi-center cohort study on the validity of the protocol. RESULTS: The test-retest consistency in terms of the oral physiological condition (Axis I) after data reduction was 0.82 [corrected] for patients with teeth problems, 0.73 [corrected] for partially edentulous patients, and 0.78 [corrected] for edentulous patients. The reliability for general health and sociological conditions (Axis II), OHRQOL (Axis III), and psychological health (Axis IV) were 0.88, 0.74, and 0.61, respectively. These values reflect either "sufficient agreement" or "excellent agreement" in accordance with the criteria established by Landis and Koch (1977) [1]. CONCLUSION: This protocol is the first multi-axis assessment scheme introduced for prosthodontic treatment with sufficient reliability. This new system is therefore expected to have a significant impact on future dental diagnostic nomenclature systems.

Clinical evaluation of a dental color analysis system: the Crystaleye Spectrophotometer®.

PURPOSE: To evaluate the clinical performance of the Crystaleye Spectrophotometer(®), a dental color analysis system. METHODS: Three color-measuring devices (Crystaleye Spectrophotometer(®), CAS-ID1, MSC-2000) were tested and the differences in color measurements among them were evaluated using Scheffe's F-test. Color measurements with the Crystaleye Spectrophotometer(®) were repeated 10 times by the same operator. The color difference (ΔE) between the first and tenth measurements was calculated. The Crystaleye Spectrophotometer(®) was used to measure the color of the maxillary left central incisor under two conditions (light and dark) and the effect of exterior lighting was analyzed to assess the accuracy of measurements. Furthermore, five different operators performed color measurements, and ΔE among the three devices was calculated. The ΔE between the target tooth and the crown of a single maxillary central incisor crown fabricated using data from the Crystaleye Spectrophotmeter(®) was calculated. Color differences between prebleaching and postbleaching were also analyzed with the Crystaleye Spectrophotometer(®) using the parameters ΔE, ΔL*, Δa*, and Δb*. RESULTS: The data from the three spectrophotometers were not significantly different. The ΔE during repeated color measurements by the same operator was 0.6. The ΔE between light and dark conditions was 0.9. The data from the five operators were not significantly different. The mean ΔE value between the target tooth and the fabricated crown was 1.2 ± 0.4, and the mean ΔE value between prebleaching and postbleaching was 3.7 ± 1.0. CONCLUSIONS: The Crystaleye Spectrophotometer(®) is an easy-to-use color analysis system producing accurate color measurements under clinical conditions.

[Functional recovery with prosthetic management for segmental resection of the mandible without reconstruction].

PATIENT: The patient, a 54-year-old male, consulted the Oral Surgery Department of Iwate Medical University Hospital with a complaint of a mass in the left oral base in June 1992. In September 1992, the patient was diagnosed as having cancer in the left mandibular base, and the tumor was excised by resection of the entire cervical region on the left side. Since radiation osteonecrosis in the left mandible and mandibular fracture were detected, segmental excision of the left mandible was performed in March 1993. Although the postoperative course was good without reconstruction, the patient consulted the Second Prosthetic Department to achieve functional recovery in February 1996. This patient had no occlusal contact between the maxilla and mandible because the mandible shifted to the affected side. After fixation of a mandibular prosthetic appliance for the defective mandible, a palatal plate for the maxilla in occlusal contact with the mandibular dentition and mandibular prosthetic appliance were fixed in November 1997. After fixation of a new mandibular prosthetic appliance and dentures for the maxilla with palatal ramp in April 2001, masticatory function was observed to have improved with control of the mandible. DISCUSSION: To prevent the mandibular shift and improvement of the masticatory function, a palatal plate with a palatal ramp in the occlusal contact region was fixed, and a balance of the masticatory muscles could be maintained. An evaluation of the level of improvement in the masticatory function and the pronunciation function indicated that the mandibular prosthetic appliance and palatal plate with a palatal ramp in the occlusal contact region increased the kind of food that the patient could take. Moreover, by enlarging the narrow Donders space, the pronunciation was improved. CONCLUSIONS: Fixation of a palatal plate with a palatal ramp in the occlusal contact region without reconstruction of the mandibular bone was useful for the control of mandibular deviation to the affected side and improvement of the masticatory function.

[A case report of treatment for complex dysfunction of occlusion and mastication due to a maxillary fracture].

PATIENT: A case report of a 39-year-old man complaining of complex dysfunction of occlusion and mastication is presented. The patient came to Iwate Medical University Hospital following urgent hospitalization and treatment at a local hospital after catching his head in a forklift. The patient consulted the Second Prosthetic Department with the purpose of occlusal examination in April, 1994 and he was diagnosed with a malunited maxillary fracture. Afterwards, surgical correction was performed, but complex dysfunction of occlusion and mastication remained. Fixed prosthesis treatment was then planned and a dental prosthesis was set in April, 2000. His prognosis has since remained favorable. DISCUSSION: At the commencement of treatment, both surgery and orthodontic treatment were considered, but the patient desired early social rehabilitation. Therefore, a dental prosthesis was used to restore facial asymmetry and mandibular function. CONCLUSIONS: Rehabilitation of occlusal function was achieved by using a dental prosthesis. This facilitated early social rehabilitation and helped improve the patient's quality of life. Since there have been few reports of cases in which a dental prosthesis was used to correct occlusal disharmony after surgical correction due to maxillary fracture, long-term follow-up will be needed for this patient in order to increase knowledge about treatment strategies for such cases.

Reproducibility of tooth color gradation using a computer color-matching technique applied to ceramic restorations.

STATEMENT OF PROBLEM: To reproduce tooth color precisely, an objective methodology based on color science is required. However, perception-based techniques are still the primary method for color matching in restorative dentistry. PURPOSE: This study evaluated the accuracy of reproduction of color gradation for ceramic restorations using a Computer Color Matching (CCM) technique employing a prototype program and spectrophotometric data measurements. MATERIALS AND METHODS: The colors of 10 target-shade tabs of the Vitapan 3D Master shade guide were measured at 4 regions of crowns from the cervical to the incisal area using a spectrophotometer. Tooth-shaped CCM ceramic specimens (30 specimens; 3 specimens for each of 10 target-shade tabs), the same size and shape as target-shade tabs, were fabricated according to the CCM prescriptions calculated using a prototype CCM program. The colors of CCM ceramic specimens and target-shade tabs were compared in 10 incremental areas from gingival to incisal (each measuring 1 mm high x 3 mm wide). The color differences, Delta E, Delta L* , Delta a* , and Delta b* , were calculated. The color difference Delta E values were analyzed by a repeated measures analysis of variance (P <.0001). Three prosthodontists evaluated CCM specimens by perception techniques. RESULTS: The mean color difference (Delta E) values were clinically acceptable (below 3.6) for incremental areas 3 through 10 and unacceptable for areas 1 and 2 (gingival area). Highly significant differences in the mean of Delta E values among target-shade tabs (P <.0001), areas (P <.0001), and target-shade tab-by-area interaction effects (P <.0001) were noted. However, perceptional evaluation indicated "Definitive match" or "Approximate match" for all CCM specimens. CONCLUSION: The CCM technique tested in this study utilizing 4 measurements on target-shade tabs could reproduce tooth color gradation from incisal to precervical regions with clinically acceptable results.

A procedure for fitting a fixed partial denture to an existing removable partial denture.

An indirect technique for fitting a new cast gold crown or fixed partial denture (FPD) to an existing removable partial denture (RPD) is presented. This method uses an acrylic resin coping made on a definitive cast fit directly to the patient's RPD intraorally, with the new FPD subsequently completed on the cast. The patient does not have to relinquish the RPD for laboratory procedures, although an appointment is required to fit the coping intraorally where contact is made with the RPD.

Comparison of effectiveness of two 10% carbamide peroxide tooth-bleaching systems using spectrophotometric measurements.

PURPOSE: The purpose of this study was to compare the color changes achieved with two commonly used bleaching systems on the basis of a spectrophotometric analysis. MATERIALS AND METHODS: Two commercially available 10% carbamide peroxide bleaching systems were used by a total of 48 individuals. Subjects who had intact natural maxillary anterior teeth void of any restorations or decay that had not been subjected to any prior bleaching were included. Opalescence 10% PF (Ultradent Products Inc., South Jordan, UT, USA) was used by 23 patients for 14 days, whereas Nite White Excel (Discus Dental, Culver City, CA, USA) was applied by 25 patients for the same duration. Tooth colors for the middle one-third region of maxillary central incisors and canines were measured with a spectrophotometer prior to bleaching and after 14 days of bleaching. Color difference deltaE and color coordinates L* (lightness), a* (redness), and b* (yellowness) of CIELAB color system (developed by the Commission Internationale de l'Eclairage) were calculated. RESULTS: Mean deltaE values for Opalescence ranged from 5.03 to 8.92 and from 5.84 to 9.61 for Nite White. The most significant factor of the color change was b* followed by L* and a*. L* values were higher after bleaching, whereas values for both a* and b* decreased. There were no significant differences between the two systems examined (p < .05).