International Journal of Esthetic Dentistry最新文献

White spot lesions are considered to be a major concern in esthetic dentistry. These lesions can be treated with noninvasive to less invasive procedures, which remain a challenge for many clinicians. The treatment of choice should be as minimally invasive as possible and should aim to minimize the color difference between the white spots and the healthy tooth enamel. Tooth whitening can be used initially to minimize this difference by rendering the extent of the white spot defects less visible, which permits a bevel effect. In addition, the microinvasive treatment option of resin infiltration, which does not involve trauma or require cavity preparation, can supplement the tooth whitening procedure to achieve excellent esthetic results, giving patients renewed confidence in their smiles. Therefore, the purpose of the present study was to illustrate the combination of dental bleaching and resin infiltration in a patient with white spot lesions caused by diffuse opacities (teeth that were undergoing enamel maturation at the time of occurrence of a systemic insult). The treatment aimed to improve the patient's esthetics, self-esteem, and quality of life.

Aim: To evaluate the influence of resin cement on the color stability of lithium disilicate and zirconia restorations immersed in coffee after aging.

Materials and methods: Eighty maxillary premolars were classified into eight groups (n = 10) based on restorative material type (lithium disilicate or zirconia), resin cement type (G-CEM LinkForce; GC Corporation or Panavia SA Cement Plus Automix; Kuraray Noritake Dental), and preheating temperature (25°C or 54°C). Following tooth preparation, each restoration was bonded to its corresponding substrate. Using a reflectance spectrophotometer, Commission Internationale de l'Éclairage (CIE) tristimulus values were detected and calculated (D65 standard illumination, 10-degree observer angle). All specimens were aged (240,000 load cycles followed by 10,000 thermal cycles), then immersed in coffee (18 h). Following that, the second measurements of the color coordinates were determined. The total color differences were measured, and the data were statistically analyzed (α = 0.05).

Results: The temperature had a significant effect on ΔL΄ (P < 0.001), ΔC΄ (P < 0.001), and ΔH΄ (P < 0.001). The lithium disilicate restorations were more color stable than the zirconia restorations. Also, there was a significant difference (P = 0.047) between the LinkForce (2.28 ± 0.48) and Panavia SA (2.15 ± 0.46) cement. The restorations cemented at a temperature of 54°C (1.76 ± 0.11) showed significant color differences (P < 0.001) compared with those cemented at a temperature of 25°C (2.67 ± 0.15). A three-way analysis of variance (ANOVA) test revealed that the interaction between the ceramic material, cement type, and temperature had no statistically significant effect (P = 0.611) on the color stability of the ceramic restorations.

Conclusions: Cement type has a significant effect on the color stability of lithium disilicate and zirconia restorations. Cement at a temperature of up to 54°C enhances the color stability of lithium disilicate and zirconia restorations.

Deep subgingival margins are a much-debated topic in adhesive and restorative dentistry. The hydrophobic trait of direct composite resin materials challenges the restorative procedure of cavities with deep subgingival margins since isolation is complicated. A correct indication for a deep margin elevation (DME) treatment is the key to its clinical success, and adequate adaptation of the DME is crucial to its clinical performance. An adequate adaptation of the DME may potentially reduce bacterial accumulation and reduce the incidence of secondary caries as well as maintain periodontal health. The present case report aims to provide a step-by-step overview of the DME technique when applied in combination with a partial indirect glass-ceramic restoration and also provides clinical guidelines to tackle deep subgingival cavities. The indication for a DME and the selection of appropriate materials are explained, supported by the literature.

Aim: The aim of the present preliminary study was to observe and make a histologic comparison of connective tissue grafts (CTGs) harvested from the lateral palatal mucosa through the use of two different harvesting techniques.

Materials and methods: Three patients were enrolled in the study, providing six standardized CTGs. One well-experienced periodontist collected the replacement grafts using two different methods. After outlining the grafts to a fixed dimension, the graft on one side was deepithelialized by a round coarse bur intraorally before harvesting. The graft on the contralateral side was obtained by harvesting from the palate first; subsequently, deepithelialization was performed extraorally with the aid of a no. 15c blade. After finalization, histologic evaluation was performed.

Results: No apparent differences were found between the two observed techniques in terms of graft thickness, proportion, and composition. After deepithelialization, epithelial remnants were clearly evident in five out of six cases. Despite being more technique sensitive, the removal of epithelium by bur scored better. Proper graft handling and graft regularity are described as advantages of the more conventional epithelial excision by blade.

Conclusions: Despite the wide use and broad variety of commonly applied techniques of graft deepithelialization, the present authors assume that full excisions with the use of a blade are hardly ever achieved. Despite the unpredictable retrieval of epithelium by blade, graft handling and graft regularity can be proposed as the biggest advantages. On the other hand, the presented novel in situ deepithelialization with a round bur seems to be more predictable.

The fracture strength of implant-supported monolithic CAD/CAM crowns under approximate clinical conditions and how their fracture strength is affected by cement type remain unclear. The present study investigated the fracture resistance of implant-supported polymer-infiltrated ceramic and zirconia-reinforced lithium silicate glass-ceramic crowns cemented with two different cement types after aging in a mastication simulator. RelyX Ultimate Clicker (3M ESPE) as adhesive resin cement, Panavia SA Cement Plus (Kuraray Noritake) as self-adhesive resin cement, and two monolithic materials (A1-T for Enamic and M1-HT for Suprinity; both Vita Zahnfabrik) were tested. Forty CAD/CAM-produced monolithic implant-supported crowns for a maxillary right second premolar were prepared, and crowns were cemented to the straight implant abutments with each cement, then subjected to dynamic load cycling (480,000 cycles) and thermocycling (about 4,000 cycles) in a mastication simulator. Crown fracture resistance was analyzed by the load-to-failure test. Crown-abutment samples were loaded until fracture. No significant difference was observed in the fracture load of the crowns among the groups. The results suggest that both monolithic restoration materials could be an alternative for implant-supported cement-retained restorations, regardless of cement type.

Purpose: The present study aimed to assess fatigue resistance and color modifications of endodontically treated incisors (ETIs) submitted to internal bleaching and restored using three different techniques.

Materials and methods: Forty-five maxillary central incisors received endodontic treatment and were internally bleached. After the completion of bleaching, the ETIs were divided into three groups (n = 15) according to the different restoration procedures: 1) glass-ionomer cement base covered with composite resin (GI); 2) short fiber-reinforced composite resin base with composite resin (SF); 3) composite resin restoration over a fiberglass post (FP). Specimens were subjected to accelerated fatigue testing: frequency of 5 Hz, beginning with a load of 100 N for 5000 cycles and a 25-N load increase applied every 1700 cycles until a load of 1200 N was reached. Samples were loaded until fracture. The Kaplan-Meier survival analysis with the log-rank post hoc test were performed (α = 0.05). Tooth color was measured 4 weeks after the bleaching treatment and again after the final restoration procedure using a spectrophotometer and the Commission Internationale de l'Eclairage (CIE) L*a*b* system. L* values of the specimens were analyzed using the Shapiro-Wilk and paired sample t tests (α = 0.05).

Results: All groups showed similar survival mean cycles until failure (P = 0.332) and presented a major number of nonrestorable failures. The GI group presented the lowest number of nonrepairable fractures (GI = 68%, SF = 79%, FP = 86%) and showed the most stable L* value (P = 0.987).

Conclusions: The fatigue survival of internally bleached ETIs was not affected by the restorative technique utilized. Retaining the glass-ionomer base and covering the surface with composite resin should provide optimal color stability.

Implants in the esthetic area are challenging for many reasons, all the more so when the hard and soft tissue are deficient at the beginning of the procedure. Numerous grafting techniques are available for the clinician, each one with its own strengths and weaknesses. It is important to understand these differences and to carry out a thorough diagnosis and case selection in order to make the right choice for each patient. The present article describes the treatment of a deficient maxillary central incisor site after extracting an ankylosed tooth. A palatal bone plate was utilized to reconstruct the missing buccal wall in the first place. Three months later, an implant was inserted and at the same time the soft tissue was augmented with a connective tissue graft. The case was successfully restored and finalized with a satisfactory esthetic outcome. The morbidity related to autogenous bone and soft tissue harvesting is discussed, but the shorter healing periods and optimal tissue quality obtained are highlighted.