Denture Design ; Denture Precision Attachment ; Humans

Speech could be used, because it was a neuromuscular movement without teeth contact. The method was stable, however it was used more in vertical relation deciding. More study was needed in the horizontal relation deciding. This article was to explain why and how to use phonetic method to decide jaws relation, through literature review.
Denture Design ; Denture, Complete ; Jaw ; Phonetics

OBJECTIVES: The objectives of this study were to assess the quality of prosthetic prescriptions of removable partial dentures (RPDs) and to analyze the current situation of the communication and information delivery between clinicians and technicians. METHODS: All RPD prosthetic prescriptions received by a major dental laboratory in 4 weeks were involved in a quality audit, and the prescriptions were divided into three groups in accordance with the grades of clients. The filling of prosthetic prescriptions was recorded. The items in the prescriptions for audit included the general information of the patient, the general information of the clinician, the design diagram information, other detailed information, and the return date. The prescriptions were categorized into four levels on the basis of their quality by two quality inspectors who have been working for more than 10 years. RESULTS: A total of 916 prescriptions were collected and assessed. The names in the general information of the patient and the clinician were filled out best, both at the rate of 97.6% (n=894). The return date was filled out worst, only at the rate of 6.4% (n=59). Of those prescriptions, 86.8% (n=795) exhibited inadequate design diagram information. The results of the quality assessment demonstrated that 74.2% of prescriptions were assessed as noncompliant ones and failed to meet the acceptable clinical quality standard. CONCLUSIONS At present, the overall quality of RPD prosthetic prescriptions is poor. The responsibilities of clinicians and technicians are unclear, and the communication between them is not ideal.
Humans ; Denture Design ; Denture, Partial, Removable ; Prescriptions

Computer-Aided Design ; Denture Design ; Humans

OBJECTIVETo compare the difference of stress distribution among models with different fiber frameworks.

METHODSFour models were generated in Marc 2003 software. Four types of loads simulating normal mastication were selected. The stress within models was calculated, and output by means of graph and data.

RESULTSThere was stress concentration around connectors and retainers near connectors under cusp -fossa load, occlusal even load, and lateral load. When dentures were reinforced with fiber framework, area of stress concentration and principal stress max could decrease in comparison with pure composite resin bonded fixed partial denture. Under buccal-lingual load, there was another stress concentration around central fossa beside above two stress concentration areas. Only modified fiber framework constructed with both mesial-distal and lingual-buccal directional glass fiber could markedly reduce principal stress under buccal-lingual cusp loads.

CONCLUSIONUnder 4 types of loads simulating normal mastication, three critical regions were disclosed at the area of retainers adjacent connectors, connectors and occlusal central fossa and fissures. Only modified fiber framework constructed with both mesial-distal and lingual-buccal directional glass fiber could markedly reduce stress concentration under buccal-lingual cusp loads.

OBJECTIVETo discuss the cause of food impaction after fixed denture restoration and to analyze the therapeutic effect of gap expansion and resin repair.

METHODSA total of 100 patients who suffered from food impaction after they received fixed partial denture were chosen. The cause of food impaction was analyzed. Treatment methods were applied on the basis of different causes. Gap expansion and resin repair were implemented to remove food impaction caused by the poor contact of the denture with healthy adjacent teeth.

RESULTSThe poor contact between fixed denture and healthy adjacent teeth was the major cause of food impaction (70%) . The effective rate of treatment among patients who received fixed partial denture but suffered from food impaction after 3 years was 100%.

CONCLUSIONSThe proposed method can be applied to treat food impaction caused by the poor contact of denture with healthy adjacent teeth.

This study aims to apply a new expert system to design removable partial denture (RPD) framework. The RPD design is completed in three steps, namely, "selecting missing teeth", "selecting abutment condition", and "selecting personalized clasp". The system can help auxiliary dentists develop personalized treatment plans to reduce their clinical workload. It can also generate a dental preparation guideline for clinical preparation, which can prevent tooth preparation mistakes. By generating the standard electronic drawings of the framework design, the system can reduce the inconvenience caused by manual drawing, thereby facilitating dentist-technician communication and reducing the rate of remade.
Dental Abutments ; Denture Design ; Denture, Partial, Removable ; Expert Systems ; Tooth

OBJECTIVEA method for 3D-data acquisition of partially edentulous cast was introduced to lay the foundation for reconstructing 3D digital model of a partially edentulous cast and studying computer aided design (CAD) to a removable partial denture framework.

METHODSUsing projection system controlled by a computer, four frames of sinusoidal fringe pattern at pi/2 intervals were projected onto the surface of partially edentulous cast consecutively within 0.4 second. Deformed fringe patterns modulated by the surface height of the cast were recorded by a digital camera. The phase value with the height information was demodulated with phase-shifting method. The transition from the unwrapped phase to the height of the points on the cast was performed with triangulation method. The multiview 3D data was integrated automatically to obtain the complete 3D profile data and the 3D digital model of the partially edentulous cast was reconstructed.

RESULTSDense and complete points-cloud data was achieved without scanning blind zone basically. The anatomic structure of reconstructed 3D digital model was sharp and clear.

CONCLUSIONAs an alternative for acquiring 3D data of partially edentulous cast, this method presented here with high precision and high speed meets the need for the subsequent 3D design to removable partial denture framework.

OBJECTIVETo explore a computer aided design (CAD) and rapid prototyping (RP) approach for fabrication of complete denture and to develop relevant programs for implementing it.

METHODSAutomatic crossing section scanner was used to scan artificial teeth and 3D graphic database of artificial teeth that could be aligned with parameters was established. A 3D laser scanner was used to scan upper and lower edentulous jaw casts and rims made in clinic. The vertical and horizontal relations were recorded before scanning with a patient instrument. Based on Imageware 11, tooth-arrangement curves, coordinate system, and landmark points for positioning were created, and construction cure and shape-controlling curve for base plate were constructed as well. Three-dimensional integrated design of complete denture, including artificial tooth automatic arrangement, aesthetic and individualized design of base plate, and artificial gingival, were finished. The programs were developed following the approach and the CAD platform was established. The virtual molds of complete dentures were constructed according to the above data in design and RP technology was used to make the plaster molds. Finally, the teeth were inserted and the complete denture was finished by dental technician.

RESULTSThe approach for the complete denture CAD/RP was confirmed and the CAD software platform was developed. A complete denture was manufactured.

CONCLUSIONSThe rules for complete denture in textbooks were expressed in design process with the CAD program developed by researcher. The 3D data of rims were utilized in design so that the digital, intelligentized and individualized design and manufacture process for complete denture was implemented.

OBJECTIVETo explore the clinical effect of combined application of magnetic attachments and extracoronal attachments in prosthodontics.

METHODSTwenty-two cases of dentition defect with isolated residual root or residual crown were selected. All the cases accepted the restorative treatment combined magnetic attachments with extracoronal attachments. The clinical effect of dentures and the condition of abutment teeth were evaluated by chief complaint of patients and clinical examination. The follow-up time ranged from 2 years to 4 years.

RESULTSSatisfactory functional, stable and esthetic results of dentures were achieved for all the cases. And there was no abutment loosening and no secondary caries. Alveolar bone loss around abutment occurred in 1 case, gingivitis of abutments appeared in 5 cases. Chewing pain occurred in 1 case and unstable state of dentures appeared in 5 cases after the use of denture for 2 years. The dentures of above-mentioned cases were used normally after symptomatic treatment.

CONCLUSIONThe combined application of magnetic attachments and extracoronal attachments in prosthodontics is an effective treatment option for cases of dentition defect with isolated residual root or residual crown.