Dental Porcelain ; Dental Prosthesis ; Dental Restoration, Permanent ; methods ; Humans

Composite Resins ; Dental Bonding ; methods ; Dental Restoration, Permanent ; methods

Composite Resins ; therapeutic use ; Dental Restoration, Permanent ; methods ; Humans

Child ; Dental Pulp Exposure ; etiology ; therapy ; Dental Restoration, Permanent ; Dental Restoration, Temporary ; Humans ; Incisor ; injuries ; Pulpotomy ; methods ; Root Canal Therapy

Acrylic Resins ; Dental Materials ; Dental Restoration, Permanent ; methods ; Denture, Partial, Fixed, Resin-Bonded

Seeing that the manual method to restore tooth has the disadvantages such as long "lead-time", assurance of quality highly depending on operator's technology, and real-time cure difficulty met by lots of dental patients coming up for tooth restoration, we put forward an algorithm of tool-path generation based on STL data model for roughing dental restoration. The algorithm can reconfigure the STL data of dental crown restoration quickly, can generates the multi-level offset wire-loop by the use of horizontal plane cutting triangle facets; and then on the basis of offset wire-loop, it can plan Zigzag and follow the contour machining tool path. The algorithm has been applied to Dental CAM software, through simulation machining, the result shows that it can not only generate interference-free tool path, but also save a lot of "lead-time" for dental restoration. Accordingly, the algorithm is of great value for reference in clinical application.
Algorithms ; Crowns ; Dental Restoration, Permanent ; methods ; Humans ; Software ; Therapy, Computer-Assisted ; methods

OBJECTIVE: To analyze the effect of ceramic onlay to repair serious defects in young permanent molars. METHODS: Sixty patients with defects in young permanent molars were selected. The patients were randomly divided into two groups. One group was restored with ceramic onlay, and the other used resin composite to direct filling. Follow-up visit was conducted at 3, 6, 12, and 24 months after treatment. Modified USPHS/Ryge criteria were used to evaluate the effect of restoration. The occlusal courses were recorded by the T-Scan Ⅲ system in intercuspal position. Gingival and food impaction were recorded. The effect of the two restorative methods, the recovery of occlusal function, and the gingival and approximal conditions were analyzed. RESULTS: At 12 months after restoration, the marginal fitness in the onlay group was significantly better than that in the resin group (P<0.05). At 12 and 24 months after restoration, the surface smoothness in the onlay group was significantly better than that in the resin composite group (P<0.05). At each follow-up visit, the resin group had significantly lower per-cen-tage of occlusal force than contralateral molar (P<0.05). The percentage of occlusal force in the onlay group and the con-trala-teral molar showed no statistical difference (P>0.05). The gingival and approximal conditions also demon-strated no stati-stical differences (P>0.05). CONCLUSIONS The ceramic onlay repair method is better than resin composite filling in marginal fitness, surface smoothness, and recovery of the occlusal function when restoring young permanent molars with serious defects.
Bite Force ; Ceramics ; Composite Resins ; Dental Restoration, Permanent ; methods ; Humans ; Inlays ; Molar ; Resin Cements

OBJECTIVETo develop a dental CAD/CAM system with the autonomic intellectual property.

METHOD28 standard teeth crowns were scanned using a newly 3-D laser scanner. As a development platform the Matlab 5.3 were used to process the acquired data, also be used to define the characterized areas on the surfaces of the crowns and to change the crowns form. The software of Surfacer 10.5 to develop a new CAD software for fixed prosthetics, and the 3.5 axis numerical controlled machine to manufacture the prosthetics were used.

RESULTIt is the first time, the 3D graphic data bank of Chinese teeth crowns with a standard form was established. A software of the occlusal adjustment and the form modification were developed. It is also the first time, the authors realized the whole process to use the CAD-CAM for the manufacture of a crown.

CONCLUSIONThe successful result shows, that we have already mastered well the base theory, the mathematics method, the technology of a CAD-CAM system. It provides the basics for the future development.

Computer-Aided Design ; Dental Prosthesis Design ; methods ; trends ; Dental Restoration, Permanent ; methods ; Dentistry, Operative ; methods ; Humans ; Research ; trends ; Research Design

OBJECTIVETo assess effects of different class II cavities on stresses of amalgam and composite resin restoration.

METHODSFive kinds of class II MO cavities were prepared on the first molars of mandibles. The cavities were filled by amalgam and composite resin, respectively. The stresses were analyzed by using three-dimensional finite element method, after vertical and lateral pressures were loaded on the teeth.

RESULTSThe stresses were greater in traditional cavities than those in reformed cavities when 100 N vertical and lateral pressures were loaded on the teeth. But the pressing stress and shearing stress in cavities filled by amalgam were smaller in traditional cavities than those in reformed cavities. The stresses were smaller in cavities filled by resin than those in cavities filled by amalgam significantly, when the cavities were designed with slot retention groove, without slot retention groove and as plate form. The stresses were smaller in two kinds of slot and plate cavities than those in traditional and reformed cavities.

CONCLUSIONIt is better to design cavity with slot retention groove for amalgam restoration and to design cavity without slot retention groove for composite resin restoration.

Composite Resins ; standards ; Dental Amalgam ; standards ; Dental Cavity Preparation ; methods ; Dental Models ; Dental Restoration, Permanent ; methods ; Dental Stress Analysis ; methods ; Finite Element Analysis ; Humans ; Mandible ; Molar

Glass ionomer Cement (GIC) is a kind of new dental restorative material. At present, GIC is finding wider use in dental clinical practice such as restoration, adhesion, cavity liner, cure of dental sensitivity and temporary restoration of cavity, because it has several excellent advantages of strong adhesive strength, low stimulation, inhibition of carious teeth. In this paper, the history of glass ionomer cement is introduced and the researching development and perspective of modified glass ionomer cement is elaborated.
Dental Bonding ; Dental Restoration, Permanent ; methods ; Glass Ionomer Cements ; chemistry ; Humans ; Root Canal Filling Materials ; chemistry ; Tensile Strength