ABSTRACT
302 teeth with wedge-shaped defect in 168 patients were restored by SDR(smart dentin replacement,n =112),glass ionomer (n =98) and light-cured composite resin(n =92) respectively.12 to 15 month follow-up showed the success rate was 96.2％,84.8％ and 86.2％ respectively(P ＜ 0.01).SDR is an ideal material in restoring wedge-shaped defect.
ABSTRACT
@#The mandibular first premolar has complicated morphology of root canal, it has more variation which increases the incidence of multiple root canals. A successful root canal therapy not only need strict cleaning, disinfection and filling, but also need a correct understanding of root canal morphology and anatomy. Otherwise there might be a risk of missing canals that resulting the failure of the therapy. Also crown closure is one of the successful elements of root canal therapy. This is a case report accompanied by a review of the literature that shows the unusual anatomy of the mandibular first molar with three roots and three root canals.
ABSTRACT
Objective To observe the effect of glass fiber post combined with gingival retraction in the treat-ment of teeth with severe wedge -shaped defect.Methods 53 patients with 120 teeth treated for severe wedge -shaped defect were selected.All the teeth were given root canal treatment,glass fiber post was applied after root canal prepared and resin was applied to fill wedge-shaped defect after gingival retraction.All the teeth were followed up for 2-3 years.Results In 2-3 years follow-up after treatment,there was no adverse outcome such as crown fracture or root fracture,neither filling material falling off in all the 53 patients with 120 teeth.The effect was good and satis-fied.Conclusion The indication should be strictly grasped and then it is convenient to apply glass fiber post com-bined with gingival retraction to treat premolar with severe wedge -shaped defect,and complete coronal restoration should be avoided to reduce the cost of health care.
ABSTRACT
<p><b>OBJECTIVE</b>The objective of this paper is to analyze the stress distribution in the deep wedge-shaped defective mandibular first premolars restored with different methods.</p><p><b>METHODS</b>Three-dimensional finite element models of mandibular first premolar with deep wedge-shaped defect were created. The model, which was untreated after root canal treatment, served as the control group. Then, according to different treatment designs, four experimental groups were established as follows: resin filling (A), post restoration after resin filling (B), crown restoration after resin filling (C), and post and crown restoration after resin filling (D). Four different post materials were then chosen for establishing the subgroup models: fiber post (B1, D1), AuPd post (B2, D2), pure Ti post (B3, D3), and CoCr post (B4, D4). A force of 100 N was applied at a 30° angle on the buccal-inclined surface near the top of the buccal cusp. The maximum principal stress and Von Mises stress were investigated using finite element analysis software.</p><p><b>RESULTS</b>1) For the control group, the maximum principal stress and Von Mises stress of the residual dentine were the same as those of the tip of the defect. 2) Compared with the control group, the maximum principal stress and Von Mises stress of groups A, B, C, and D decreased greatly (P<0.05). The maximum principal stress and Von Mises stress of groups C and D with crowns were similar. The maximum principal stress and Von Mises stress of the post-dentine surface of groups B and D with fiber post were less than those in the cast metal post models (P<0.05). 3) The displacement of the buccal cusp of group A was similar to that of the control group (P>0.05) and larger than those in groups B, C, and D (P<0.05).</p><p><b>CONCLUSIONS</b>It is necessary for deep wedge-shaped defective teeth to be treated with full crowns, but a post is not necessary. If a post is used, fiber post with elastic modulus closer to the dentine is more suitable than metal post. .</p>
Subject(s)
Humans , Bicuspid , Crowns , Dentin , Finite Element Analysis , Post and Core Technique , Root Canal Therapy , Tooth CrownABSTRACT
Objective:To observe the effect of “bulk-fill”flowable resin in filling deep wedge-shaped defects.Methods:50 pa-tients with totally 85 pairs of premolars with deep wedge-shaped defects(depth >2 mm)were included.Each pair of the defects was randomly divided into the test group and the control group,the defects were treated by “bulk-fill”flowable resin with single cure tech-nique and conventional flowable resin with incremental layering technique respectively,the tooth sensitive rate 1 week after filling,the filling failure rate,the edge coloring and secondary caries rate 2 years after filling of the 2 groups were compared.Results:There was no significant difference between the 2 groups in the sensitive rate 1 week after filling,the failure rate and the edge coloring and sec-ondary caries rate 2 years after filling(P >0.05).Conclusion:The “bulk-filled”flowable resin using single cure technique can ac-quire the same clinical effect as conventional flowable resin using incremental layering technique in filling deep wedge-shaped defects.
ABSTRACT
Objective To study the main factors of young people the wedge-shaped teeth defect.Methods Random sampling way,746 middle-aged and young people in 20-50 years old with the wedge-shaped teeth defect patients status were checked,the oral examination and questionnaire survey was used to surveyed the factors on the young people of wedge-shaped defects.Results The young people of wedge-shaped defects in the reason,the most common was the mechanical friction 576 cases accounted for 75.4％,followed by etching 422 cases accounted for 56.6％,in addition to bite force fatigue in 112 cases accounted for 15.0％,other 46 cases,accounting for 6.7％.Conclusion The young people oral care has many defects,but also exposed many problems,the wedge-shaped teeth defectand oral care,using habit has the very big relations,and the prevention was the mainly measure for the wedgeshaped teeth defect.
ABSTRACT
PURPOSE: To evaluate the efficiency of digital retinal nerve fiber layer (RNFL) photographs converted from a non-mydriatic digital fundus camera for detecting RNFL defects. METHODS: Ninety-five eyes were evaluated with both a non-mydriatic digital fundus photograph and a digital RNFL photograph by two glaucoma specialists independently. The red-free, monochrome modified digital fundus photograph was acquired from non-mydriatic digital fundus photographs using Photoshop 7.0. Whether a localized wedge-shaped or diffuse RNFL defect existed or not was evaluated on a non-mydriatic digital fundus photograph and a modified digital fundus photograph, and inter- and intraobserver agreement were also evaluated. Regarding the use of digital RNFL photographs as a standard method, we calculated the sensitivity, specificity, and positive and negative predictive values of the two types of photographs. RESULTS Interobserver agreement (Cohen's kappa values) about localized RNFL defects observable on digital RNFL photographs, non-mydriatic digital fundus photographs, and modified digital fundus photographs were 0.749, 0.634, and 0.793, respectively, but all were 0.417 or less with regard to diffuse RNFL defects. Regarding localized RNFL defects, the sensitivity, specificity, and positive and negative predictive values of modified digital fundus photographs were 85.7%, 95.5%, 85.7% and 94.1%, respectively, showing superiority to those of non-mydriatic digital fundus photographs. But, in cases of diffuse RNFL defect, the sensitivity and specificity of modified digital fundus photographs were 60.0% and 97.8%, respectively, indicating no superiority to non-mydriatic digital fundus photographs. CONCLUSIONS: The localized RNFL defect can be detected more efficiently with modified digital fundus photographs than non-mydriatic digital fundus photographs, but the diffuse RNFL defect cannot.
Subject(s)
Glaucoma , Nerve Fibers , Retinaldehyde , Sensitivity and Specificity , SpecializationABSTRACT
PURPOSE: To evaluate the efficiency of digital retinal nerve fiber layer (RNFL) photographs converted from a non-mydriatic digital fundus camera for detecting RNFL defects. METHODS: Ninety-five eyes were evaluated with both a non-mydriatic digital fundus photograph and a digital RNFL photograph by two glaucoma specialists independently. The red-free, monochrome modified digital fundus photograph was acquired from non-mydriatic digital fundus photographs using Photoshop 7.0. Whether a localized wedge-shaped or diffuse RNFL defect existed or not was evaluated on a non-mydriatic digital fundus photograph and a modified digital fundus photograph, and inter- and intraobserver agreement were also evaluated. Regarding the use of digital RNFL photographs as a standard method, we calculated the sensitivity, specificity, and positive and negative predictive values of the two types of photographs. RESULTS Interobserver agreement (Cohen's kappa values) about localized RNFL defects observable on digital RNFL photographs, non-mydriatic digital fundus photographs, and modified digital fundus photographs were 0.749, 0.634, and 0.793, respectively, but all were 0.417 or less with regard to diffuse RNFL defects. Regarding localized RNFL defects, the sensitivity, specificity, and positive and negative predictive values of modified digital fundus photographs were 85.7%, 95.5%, 85.7% and 94.1%, respectively, showing superiority to those of non-mydriatic digital fundus photographs. But, in cases of diffuse RNFL defect, the sensitivity and specificity of modified digital fundus photographs were 60.0% and 97.8%, respectively, indicating no superiority to non-mydriatic digital fundus photographs. CONCLUSIONS: The localized RNFL defect can be detected more efficiently with modified digital fundus photographs than non-mydriatic digital fundus photographs, but the diffuse RNFL defect cannot.
Subject(s)
Glaucoma , Nerve Fibers , Retinaldehyde , Sensitivity and Specificity , SpecializationABSTRACT
Objective To study the effect of CEREC CAD/CAM ceramic inlay on repair of wedge-shaped defects of teeth and test its anti-fracture properties. Methods Extracted teeth were divided into control group ( n = 16) and experimental group ( n = 16) ,and prepared into imitating teeth with wedge-shaped defects. Teeth in experimental and control groups were repaired with CEREC CAD/CAM ceramic inlay and light-cured composite resin,respectively. Anti-fracture strength of teeth with wedge-shaped defects repaired with CEREC CAD/CAM was assayed on a universal testing device with its maximal loading recorded. The anti-fracture strength was compared between the 2 groups. Results The anti-fracture strength of teeth with wedge-shaped defects repaired with CEREC CAD/CAM ceramic inlay was significantly higher in experimental group than in control group ( 3. 56 ? 0. 27 vs 2. 43 ? 0. 15,P
ABSTRACT
We investigated differences in clinical findings among normal-tension glaucoma(NTG)patients between those with wedge-shaped nerve fiber layer(NFL)defect and with diffuse atrophy. Forty-one eyes of patients with NTG having diurnal intraocular pressure < 21mmHg, glaucomatous visual field defect, optic disc analysis with Heidelberg Retina Tomograph(HRT), and brain magnetic resonance imaging were divided into wedge-shaped defect group and diffuse atrophy group according to the types of NFL atrophy. We found no difference between two groups in the mean deviation of visual field, area of peripapillary atrophy measured with HRT, and presence of peripapillary atrophy. The patients with diffuse atrophy were older than those with wedge-shaped defect(p=0.01). The intraocular pressure was slightly higher (p=0.02)and maximal cup depth was larger(p=0.03)in patients with wedge-shaped defect compared with diffuse atrophy. Cerebral small vessel disease was more frequent in patients with diffuse atrophy than with wedge-shaped defect(p=0.02). This study suggests that cerebral small vessel disease is more common in patients with diffuse atrophy and potentially suggests indirectly ischemia may cause more diffuse damage than localized damage in patients with NTG.