Full Crown Research Articles

Treatment of Teeth with an Insufficient Clinical Crown. Part 2: Treatment Cost and Time and Patient Outcomes.

This study involves a group of 168 teeth in 126 patients treated with crown lengthening and tooth reconstruction (experimental group), and a group of 75 teeth from 62 patients that were judged irrational to treat, extracted, and replaced (control group). In the control group, 13 teeth in 12 patients were not replaced; 37 were replaced with an implant-supported crown, 14 with a tooth-supported partial denture, 2 with a Maryland partial denture; and 9 patients requested a removable prosthesis. In the experimental group, 44 teeth in 37 patients received a conservative restoration (24 direct and 20 indirect), while 124 teeth in 94 patients received a full crown. All 168 teeth were surgically treated with minimally invasive crown lengthening. Endodontic treatment and orthodontic extrusion were applied when necessary. Treatment resulted in healthy periodontal and dental/implant conditions at the 1-year follow-up in both groups. Function and esthetics were described from satisfactory to extremely satisfactory by patients of both groups, with the exception of three patients in the control group who received a mobile prosthesis restoration and reported some difficulties in chewing. When comparing treatment cost and duration of the reconstructed teeth (experimental group) to the treatment cost and duration of extracted and replaced teeth (control group), the difference is significantly in favor of the preservation of natural teeth, both monetarily and in terms treatment time. Saving a tooth with a compromised crown is more favorable for the patient than extraction and replacement. This conservative approach is advisable to clinicians whenever the clinical conditions enable treatment.

Effect of Root Canal Therapy Combined with Full Crown Restoration on the Level of Inflammatory Factors and Chewing Function in Patients with Cracked Teeth and Chronic Pulpitis.

Objective To explore the clinical effect of root canal therapy combined with full crown restoration in patients with cracked teeth and chronic pulpitis. Methods From May 2018 to June 2020, 87 patients with cracked teeth and chronic pulpitis in our hospital were selected; the patients were randomly divided into the control group and the research group by random number method. The control group only used root canal therapy; the research group used root canal therapy combined with full crown restoration. The therapeutic effect, levels of inflammatory factors, chewing function, periodontal index, complications, and quality of life were compared between the two groups. Results The total effective rate of the research group (97.78%) was better than the total effective rate of the control group (85.71%) (P < 0.05). Compared with before treatment, the serum levels of interleukin-1β (IL-1β), IL-6, and C-reactive protein (CRP) of the two groups of patients decreased after treatment. After treatment, compared with the control group, the serum levels of IL-1β, IL-6, and CRP in the research group decreased (P < 0.05). Compared with before treatment, the bite force of teeth and chewing efficiency of the two groups of patients increased after treatment. After treatment, compared with the control group, the bite force of teeth and chewing efficiency of the research group increased (P < 0.05). Compared with before treatment, the plaque index (PLI), probing depth (PD), gingival sulcus bleeding index (BI), and gingival index (GI) of the two groups of patients decreased after treatment. After treatment, compared with the control group, the PLI, PD, BI, and GI of the research group decreased (P < 0.05). The total incidence of complications in the research group was (11.11%), and the total incidence of complications in the control group was (16.67%); there was no significant difference between the two groups (P > 0.05). After treatment, compared with the control group, the quality of life scores of the patients in the research group were reduced (P < 0.05). Conclusion Root canal therapy and full crown restoration have a definite curative effect in patients with cracked teeth and chronic pulpitis, which can improve the inflammatory response, restore chewing function, maintain periodontal health, improve the quality of life, and do not increase the incidence of complications, so it has good application value.

Full coverage crowns for rehabilitation of MIH affected molars: 24month randomized clinical trial.

Teeth affected with severe molar incisor hypomineralization (MIH) require extensive restorations, which do not last for a long time and often require treatment in the form of onlays or full coverage restorations. To evaluate and compare the clinical performance of zirconia, lithium disilicate, and cast metal crowns as full-coverage restorations on MIH-affected first permanent molars (FPMs). 60 MIH affected FPMs requiring full-coverage crowns were identified in children aged 8-15years and were randomly allocated to the three treatment groups according to the type of full coverage restoration received using block randomization technique. After an adequate removal of the MIH defect and restoration with composite resin, the tooth preparation was done followed by fabrication of crown and its cementation using resin cement. The intergroup comparison was done on the basis of USPHS criteria, gingival, plaque scores, patient and parents acceptance through a visual analog scale to decipher their clinical performance at 6, 12, 24months. After 24months, the crowns showed similar clinical success in terms of the criterias used to compare their clinical performance. The retention, marginal adaptation, relief from hypersensitivity, proximal contact, gingival health with no statistically significant difference among the three groups. Based on the observations, Lithium disilicate, Zirconia and full cast metal crowns showed similar clinical success in rehabilitation of First permanent molars with severe MIH over 24months of evaluation. The clinical success is not influenced by the material of the restoration. However, prospective studies with a longer follow-up are required to reach a more definitive conclusion.

Prevention and treatment of food impaction after full crown restoration: step by step

Prevention and treatment of food impaction after full crown restoration: step by step

Comparison of Fracture Resistance for Chairside CAD/CAM Lithium Disilicate Crowns and Overlays with Different Designs.

To determine the fracture resistance of chairside computer-aided design and computer-assisted manufacturing (CAD/CAM) lithium disilicate full coverage crowns and two different designs of overlay restorations for premolars. CAD/CAM lithium disilicate (IPS e.max CAD for CEREC/HT A1 C14, Ivoclar Vivadent) restorations (15 specimens/group) with 1.5 mm occlusal thickness and 1.0 mm chamfer were designed and fabricated with a chairside CAD/CAM system (CEREC, Dentsply Sirona). The restorations were prepared in three different designs: (1) full coverage crowns, (2) overlays with the margin located 2 mm above the gingiva, and (3) overlays with the margin located 4 mm above the gingiva. Restorations were cemented using conventional resin luting cement (Multilink, Ivoclar Vivadent) with primer system (Monobond Plus, Ivoclar Vivadent) to resin printed dies, load cycled (2,000,000 load cycles at 1 Hz with 275 N force), and then finally loaded with a steel indenter until failure. Scanning electron microscopy observations of fractured surfaces were also conducted. Group results were analyzed with one-way analysis of variance, and the medians were evaluated independently with Kruskal-Wallis. The fracture force of CAD/CAM lithium disilicate restorations was significantly different (p < 0.001) depending on the design of the restoration. Full coverage crowns showed significantly higher force to fracture (1018.8 N) than both types of overlays (p = 0.002 for overlay 2.0 mm and p < 0.001 for overlay 4.0 mm above gingiva). Among the two overlays, the restoration with the margin located 2 mm above the gingiva showed significantly higher fracture force (813.8 N) than the overlay with margin at 4 mm above the gingiva (436.1 N; p < 0.001). The fracture appearance of the crowns was much more complex than that of the overlay restorations. Full coverage chairside CAD/CAM lithium disilicate premolar crown showed higher fracture resistance than overlay restorations. Overlays with the margin located 2 mm above the margin demonstrated higher resistance than those with the margin located 4 mm above the gingiva.

Effect of the haptic 3D virtual reality dental training simulator on assessment of tooth preparation

Background/purposeThe haptic 3D virtual reality dental training simulator has been drawn attention as a educational strategy in Covid-19 pandemic. The purpose of this study is to investigate the feature of the haptics simulator in comparison with a conventional mannequin simulator by analyzing the assessment of products prepared by dental students using these two kinds of simulator. Materials and methodsThe subjects were 30 students in the sixth-year classes of the faculty of dentistry. Abutments for a full cast crown were prepared by each subject using two kinds of simulator; one is the haptics simulator and the other is a mannequin simulator. For the resulted products, occlusal surface form, margin design, surface smoothness, taper angle, total cut volume and overall impression were rated by 3 evaluators. Score differences between two simulators were statistically analyzed. ResultsThe kinds of simulator affected subject performance for margin design and total cut volume. The differences in cutting feeling between the simulators as well as variation of stereoscopic ability in subjects were considerable reasons. Evaluators’ rating was affected by difference in simulators for occlusal surface form, total cut volume, and overall impression. This may have been due to variation of stereoscopic ability in evaluators. ConclusionThe unique characteristics of virtual reality, such as the simulated cutting sensation and the simulated three-dimensional images created by stereo viewers, affect operators’ performance and evaluators’ rating. It was suggested that educational programs need to be constructed taking account of the characteristics of virtual reality to make the best use of the haptics simulator.

Comparison of the Effect of Full Crown and High Inlays Restoration after Root Canal Treatment of Posterior Dental Defects

Comparison of the Effect of Full Crown and High Inlays Restoration after Root Canal Treatment of Posterior Dental Defects

English

The undesirable discoloration or pitting of teeth due to fluorosis or developmental defects like amelogenesis imperfecta or enamel hypoplasia pose a challenge to the clinician to cater to the aesthetic requirements of patients. Fluorosis had been reported way back in 1901. There are treatment options depending upon individual cases as follows: microabrasion / macroabrasion, bleaching, composite restoration, veneers or full crowns. For the aesthetic enhancement of stains associated with mild to moderate fluorosis enamel microabrasion is the preferred treatment. This technique involves removal of entrapped stains by rubbing of slurry containing HCl acid and an abrasive agent on the stained enamel surface. But if the depth of the defect is more then microabrasion can be done in conjunction with bleaching or bonded restorations can be done to achieve optimal aesthetics. Casein phospopeptide - Amorphous calcium phosphate (CPP – ACP) can be topically applied after microabrasion which enhances remineralisation and prevents post-operative sensitivity. The present paper illustrates the management of mild to moderate dental fluorosis by microabrasion to remove stains on the enamel surface followed by remineralisation using CPP - ACP paste. An unaesthetic smile has psychological impact especially on young patients and lowers their confidence.1 Discoloration of the young permanent anterior teeth is mostly seen due to varying developmental defects. This could be due to extrinsic aetiology such as those caused by coffee, tea, red wine and tobacco or due to intrinsic aetiology. The intrinsic stains may be due to pre-eruptive or post-eruptive causes.2 Pre-eruptive causes of intrinsic stains include dentinogenesis imperfecta and fluorosis, whereas post-eruptive causes of intrinsic stains include tetracycline dentine staining or due to injuries.3 The excessive and chronic ingestion of fluoride during amelogenesis leads to fluorosis which can be skeletal or dental depending upon the intake.4,5 Dental fluorosis is characterized by white opaque flecks on teeth or yellow to brown discolorations with pitting on the enamel surface.6,7 The enamel microabrasion is an effective and non-invasive procedure for removing the stains limited to outer enamel layer.7,8 It uses a rubber cup along with abrasive materials and chemical solutions.9,10 Currently, many products are commercially available for enamel microabrasion such as Prema Compound (Premier Dental Products, Norristown, PA, USA) containing 15 % HCl and Opalustre (Ultradent, South Jordan, UT, USA) containing 6.6 % HCl and silicon carbide.7 (Table 1) Since these products are expensive, the prototype paste containing 18 % HCl and pumice, as described by Croll in 1986 is most commonly used in clinical practice.8

BİR ANTERİOR AÇIK KAPANIŞ VAKASININ PROTETİK REHABİLİTASYONU: OLGU SUNUMU

Açık kapanış ile ilişkili fonksiyonel bozukluklar ve morfolojik düzensizliklerin tedavisi, büyüme ve gelişimin farklı evrelerinde farklı tedavi yöntemleriyle yapılmaktadır. Dişsel açık kapanış, ortodontik ve protetik uygulamalarla tedavi edilebilirken iskeletsel açık kapanış tedavilerinde ortognatik cerrahi yöntemler, ortodontik tedavi ve protetik uygulamaların tek veya birlikte uygulanması estetik ve fonksiyonel başarıyı arttıracaktır. Bu çalışmanın amacı, anterior açık kapanış olgusunun bir vaka üzerinden tam seramik kuronlarla rehabilitasyonunu anlatmak ve tedavi sonucunu paylaşmaktır. Anterior bölgede estetik başarı, klinik ve laboratuvar çalışmalarının yanı sıra doğru tanı ve tedavi planına da bağlıdır. Bu vakada dişsel anterior açık kapanışı olan 21 yaşındaki hastaya tüm tedavi seçenekleri anlatıldı, hastanın isteği üzerine uzun süreceğini düşünülen ortodontik tedavi yerine protetik tedavi planlaması yapıldı. Preparasyonu yapılan dişlerde dişeti retraksiyonu yapıldı ve ölçüsü alındı. Tam seramik (IPS Empress E-max) kuronlar ve monolitik zirkonya ( Katana HT Blok) kuronların tüm laboratuvar işlemleri tamamlandıktan sonra simantasyonları yapıldı. Tedavi sonrasında estetik ve fonksiyon açısından başarılı sonuçlar elde edildi ve hasta memnuniyeti sağlandı. 3, 6 ve 12 aylık klinik ve radyografik kontrol muayenelerinde yumuşak doku ve dişlerin sağlığının klinik olarak uygun olduğu saptandı. Anahtar Kelimeler: Anterior Açık Kapanış, Protetik Restorasyon, PROSTHETIC REHABILITATION IN A CASE WITH ANTERIOR OPEN-BITE: A CASE REPORT ABSTRACT Functional disorders associated with open-bite and treatment of morphological irregularities are performed at different stages of growth and development with different treatment methods. While dental open-bite can be treated with orthodontic and prosthetic treatments, orthognatic surgical methods, orthodontic treatment and single or combined application of prosthetic applications in skeletal open-bite treatments will increase aesthetic and functional success. The aim of this study is to explain the rehabilitation of anterior open-bite with full ceramic crowns in a case and to share the treatment results. Aesthetic success in the anterior region is dependent not only on clinical and laboratory work, but also on the correct diagnosis and treatment plan. In this case, prosthetic treatment stages of the 21-year-old case with dental anterior open-bite were explained through the case report. All treatment options were explained to the patient but prosthetic treatment planning was done instead of orthodontic treatment which he thought to be long. Gingival retraction was performed on the teeth that had been prepared and the measure was taken. Full ceramic (IPS Empress E-max) crowns and monolithic zirconia (Katana HT Block) crowns were cemented after all laboratory procedures were completed. Successful results in terms of aesthetic and function were obtained after the treatment and patient satisfaction was achieved. Clinical and radiographic control examinations of 3, 6 and 12 months have been found to be clinically appropriate for soft tissue and teeth health. Keywords: Anterior open-bite, Prosthetic restoration, Full crown

Metal-ceramic and porcelain-veneered lithium disilicate crowns: a stress profile comparison using a viscoelastic finite element model

Metal-ceramics (MC) are one of the oldest dental restorative systems, which are considered to be the gold standard for full crown restoration. Porcelain-veneered lithium disilicate (PVLD), on the other hand, are newer material systems that have shown high survival rate in clinical follow-ups but needs to be studied more. This study compares the stresses developed in the single crowns made from newer PVLD system against those with MC configuration. For this comparison, influence of the layer thickness and cooling rates is also taken into consideration. An experimentally validated viscoelastic finite element model (VFEM) has been developed to predict the stress profile in these systems. Three-dimensional rotationally symmetric crowns were analyzed using this validated model for both material systems, three veneer to core thickness ratios (2:1, 1:1, 1:2), and two cooling rates: slow cooling at 1.74E-5 W/mm2 (∼30 K/min) and fast cooling at 1.74E-4 W/mm2 (∼300 K/min). PVLD showed lower values of transient and residual stresses than MC. The maximum tensile residual stresses in MC systems were observed in the cusp area, whereas those in PVLD were located in the central fossa. With the reduction in veneer layer, there was reduction in residual stress in MC; however, the veneer thickness had little to no effect in PVLD. The effect of cooling rate was also evident as slow cooling resulted in lower residual and tensile stresses for both material systems.

INFLUENCE OF PORCELAIN FIRING AND CORE THICKNESS ON MARGINAL GAP OF CAD/CAM AND PRESSABLE ALL-CERAMIC CROWNS (IN-VITRO STUDY)

Statement of Problem: Marginal gap is important for the long-term success of all-ceramic restorations, the marginal accuracy of different manufacturing techniques and core thicknesses must be considered. Purpose: This study compared marginal gap of CAD/CAM and heat-pressed ceramic cores with different thicknesses before and after veneering porcelain application. Materials and Methods: A standard die was prepared. Sixty resin dies were duplicated. Samples were divided into two groups, Group I: samples were fabricated by CAD/CAM, Group II: samples were fabricated by heat pressing. Each group was divided into three subgroups: Subgroup 1: cores of 0.3 mm. thickness, Subgroup 2: cores of 0.5 mm. thickness, Subgroup 3: full contoured crowns were manufactured by characterization technique. marginal gap was measured at core stageand after veneering porcelain firings using a microscope . Results: Marginal gaps of CAD/CAM samples in all subgroups were higher than pressable(P˂0.05), A significant increase in the marginal gap was observed after porcelain firing, Full contour crowns recorded the lowest marginal gap(58.54±9.1, 32.76±8.5) followed by 0.5mm.( 66.7±8.4, 40.06±4.1) while 0.3mm. thickness recorded the highest value (81.14±12.3, 47.96±7.15). Significant difference in pre-firing and post firing gap values in 0.3mm. thickness(P=0.001), while in 0.5mm. thickness and full contour there were no significant difference (P=0.657 and 0.88 respectively). no statistically significant difference in mean marginal gap between 0.5 mm. and 0.3mm. at both pre-firing and post-firing. Conclusion: Marginal gap were all within the clinically acceptable range. Marginal gap increased after porcelain firing. for esthetic reasons, 0.3mm core thickness can be used instead of 0.5mm.

One Year Clinical Evaluation of Milled BioHPP Polyetheretherketone (PEEK)-Based versus Metal Ceramic Single Crowns (Randomized Controlled Clinical Trial)

Objective: To evaluate the clinical behavior of milled BioHPP PEEK copings veneered with Visio.lign composite resin in comparison with metal copings veneered with feldspathic porcelain as single posterior crowns. Material and Methods: Twenty Four full coverage posterior crowns were fabricated for endodontically treated molars divided into 2 groups according to the material used. Twelve milled BioHPP PEEK-based crowns (Group 1) and Twelve Porcelain Fused to Metal (PFM) crowns (Group 2). The preparations were standardized with an equi-gingival, deep chamfer finish line for all teeth. BioHPP PEEK and metal copings were fabricated by CAD/CAM technology and lost wax technique respectively. These coping were veneered according to manufactures instructions either by special composite resin or low fusing glass ceramic respectively. The restorations were cemented then clinical evaluation of these crowns was assessed regarding mechanical failure, marginal integrity and patient satisfaction every two months for one year. Results: Although two PEEK crowns were fractured, both PEEK and PFM crowns showed similar fracture (mechanical failure) and marginal integrity without significant difference (P &gt; 0.05). BioHPP PEEK-based crowns showed statistically significantly lower patient satisfaction than PFM crowns after six months (P-value = 0.013, Effect size = 1.157) but all the patients were generally satisfied. Conclusion: BioHPP PEEK-based crowns showed clinically similar and accepted mechanical behavior and marginal integrity but less patient’s satisfaction than PFM crowns after six months. So BioHPP PEEK-based crowns may be used as an alternative tooth-colored metal-free fixed restoration for one year. Keywords BioHPP; Metal ceramic; Patient satisfaction; PEEK; PFM.

EFFECT OF A NOVEL CERAMIC SURFACE TREATMENT ON THE RETENTION OF LITHIUM DISILICATE CROWNS BONDED WITH TWO DIFFERENT LUTING APPROACHES AN INVITRO STUDY

Aim: to evaluate the effect of the novel one step ceramic surface treatment on the retention of lithium disilicate crowns cemented with two different luting approaches (self-etch and self- adhesive resin cements) compared to the conventional surface treatment technique. Materials and methods: 28 extracted molar teeth were prepared to receive full coverage lithium disilicate glass ceramic crowns with lateral projections for pull out test. The crowns were divided into 2 main groups according to the surface treatment applied, Group 1: conventional surface treatment by hydrofluoric acid followed by silane coupling agent(HF+silane), Group 2: the new self-etching ceramic primer Monobond etch and prime(MEP). Each group was subdivided into 2 subgroups according to cementation protocol: In Subgroup A crowns were bonded using self- etch resin cement (Rely X Ultimate) while in subgroup B, crowns were bonded using self- adhesive resin cements (Rely X U200). Crowns were tested for retention using pull out test until failure occurred. Results: Group 2 showed statistically insignificant higher retention mean value (204.63±35.30 N) than Group 1(196.21±39.76 N), while subgroup A (265.75±49.35 N) showed statistically significant higher retention mean value than subgroup B (135.09±25.71 N). Subgroup 2A (MEP and Rely X Ultimate) had the highest bond strength (267.42 ±40.92 N) followed by 1A (HF+ silane and Rely X Ultimate), 2B (MEP and Rely X U200), 1B(HF+ silane and Rely X U200). Conclusion: Self-etching ceramic primer MEP is strongly recommended to replace conventional surface treatment. Self-etching ceramic primer(MEP) with self-etch resin cement provided the highest bond strength.

CLINICAL EVALUATION AND PATIENT SATISFACTION OF SHADE MATCHING BETWEEN NATURAL TEETH AND MONOLITHIC ALL-CERAMIC CROWNS FABRICATED FROM TWO MATERIALS (Randomized Controlled Clinical Trial)

Aim: The aim of the present study was to evaluate color difference between zirconia reinforced lithium silicate ceramic (Celtra Press) VS lithium disilicate glass ceramic (e.max) in relation to natural tooth structure to determine which monolithic material will provide restoration with exact shade and optical properties as natural tooth structure. Materials and Methods: 20 teeth esthetic zone requiring full coverage crown -with their adjacent/contralateral are sound and not severely discolored - were prepared to receive an all ceramic crown. The crowns will be divided into two groups , patient satisfaction of the two groups assessed using the Visual Analogue Scale (VAS). Shade matching to the contral lateral tooth was evaluated by 3 experienced evaluators modified United States public health service (USPHS) criteria as Alpha (Excellent), Bravo (Acceptable), Charlie (Acceptable but modifications needed), and Delta (Unacceptable). The color difference ΔE (perceptibility threshold) was measured using intraoral spectrophotometer and evaluated for each group. Results: Patient satisfaction was graded according to the visual analogue scale (VAS). There was no statistically significant difference between (Group I) and (Group II) where (p=1) as both groups showed (100%) Alpha. Moreover, shade matching was graded according to USPHS. There was no statistically significant difference between (Group I) and (Group II) where (p=1) as both groups showed (100%) Alpha. The results for both materials in terms of patient satisfaction and shade matching were Alpha. Conclusions: Within the limitations of this clinical study, Celtra Press and IPS e.max press full coverage restorations revealed excellent patient satisfaction and color matching.

Treatment of Teeth with Insufficient Clinical Crown. Part 1: One-Year Clinical Outcomes of a Minimally Invasive Crown-Lengthening Approach.

This study describes a clinical strategy based on a flowchart developed to facilitate the treatment of teeth with a severely compromised clinical crown. A group of 168 teeth in 126 patients required periodontal surgery and received a minimally invasive crown-lengthening procedure with the aim to reach a minimal supracrestal tissue attachment width of 2.5 mm, including a free space between the cervical margin of the restoration and the bottom of the sulcus. Surgery was performed with the aid of an operating microscope and microsurgical instruments, trying to reduce bone surgery and invasiveness as much as possible. An average postsurgical radiographic bone resection of 1 ± 0.6 mm was measured. Endodontic treatment was necessary in 73 teeth, re-treatment in 51. Most of the teeth (124 in 94 patients) received a full crown, while the remaining 44 received a direct (24 teeth) or an indirect (20 teeth) reconstruction. Six teeth were orthodontically extruded before surgery. The 1-year average pocket depth at the treated units was 2.5 ± 0.5 mm, resulting in a reduction of 0.7 ± 0.9 mm compared to the preoperative measurement (P < .0001). Bleeding on probing was detected in 19 sites (11.3%) and was significantly reduced from the preoperative condition (57 sites, 33.9%). The distance between the apical margin of the restoration and the gingival margin was 0.2 ± 0.4 mm (range: 0 to 1 mm); clinical attachment level was 2.7 ± 0.6 mm. A clinical approach based on minimally invasive crown lengthening with minimal or no ostectomy and high-quality restorative dentistry resulted in healthy periodontal and dental condition of all the treated units at the 1-year follow-up.

BLEACHING WITH 37.5% HYDROGEN PEROXIDE-A CASE REPORT

Today's dentists have a variety of treatment options for restoring a smile with discoloured vital teeth. Treatment options include full crowns, veneers, and direct restorations, as well as minimally invasive procedures such as microabrasion, macroabrasion, and bleaching. Bleaching of teeth is the least invasive and conservative treatment option, so it is gaining popularity. The purpose of this case report is to describe an in-office vital tooth bleaching case in a young patient using POLA OFFICE + (37.5%percent hydrogen peroxide gel). By the end of the second visit, the results were satisfactory, with no side effects.&#x0D; Keywords: In office Bleaching, Pola Office +, Discoloration

Assess the Radiological Change of Post Extraction Socket after Using Beta Tricalcium Phosphate for Understanding of Bone Formation

Background: Bone healing is an important subject in various fields of dentistry such as prosthesis, implant, surgery, etc. Numerous studies and researches have been done on tooth socket healing process however, most of these studies are histological evaluations and less are radiographic studies. Aim: The aim the Study was the Radiological Change of Post Extraction Socket after Using Beta Tricalcium Phosphate for Understanding of Bone Formation. Methods: The experimental Study was conducted in the department of oral and maxillofacial of in Bangabandhu Sheikh Mujib Medical University Hospital (BSMMU), Dhaka, Bangladesh to find out the common indications of Post Extraction Socket. 20 patients (Group-A) whose full veneer crown were prepared on Alloplastic bone substitute and another 20 patients (Group-B) whose were without alloplastic bone substitute. 40 cases were randomly selected for the study whose common indication of Radiological Change of Post Extraction Socket after Using Beta Tricalcium Phosphate. Clinical examination and evaluation were done from October 2010 to February 2011. Other necessary investigations were done if clinically indicated and to prepare the patient for anesthesia. Statistical analysis of the results was obtained by using window-based computer software devised with Statistical Packages for Social Sciences (SPSS-22). Results: Table shows the distribution of the age of the patients. Majority of the patients 22(55.0%) were of 18-25 years age group and another 15(37.5%) were at their 26-35 age group. Mean age of the patients was 25.97±4.99 years. Conclusion: Both QDSR and LRA methods can be used in evaluation of the rate of bone formation in the tooth socket but the former method is more accurate.

The influence of FRC base and bonded CAD/CAM resin composite endocrowns on fatigue behavior of cracked endodontically-treated molars

Cracked endodontically treated molars (ETMs) are commonly treated with full crowns. Less invasive techniques could include fiber-reinforced composite (FRC) base and adhesively bonded endocrowns. The purpose of this study was to assess the fatigue resistance of ETMs restored with CAD/CAM resin composite endocrowns and reinforced with different FRC bases. Cracks were simulated in fifty mandibular molars by cutting the teeth longitudinally and reassembling the two parts. After performing endodontic treatments and preparing cavities, teeth were restored in one of the following methods (n = 10). In Group 1, cavity floors were lined with 0.5 mm of flowable composite (Universal Injectable; GUI, shade A2). In Groups 2 and 3, the cavity floors were covered with one and three layers of FRC-net (ES Net) respectively, whereas in Groups 4 and 5 with 1 mm and 2 mm of flowable FRC-resin (EverX Flow Dentin; EXFD) respectively. Endocrowns (Cerasmart 270; CE, A2 HT) with 5 mm thickness were adhesively luted with preheated composite and all specimens were subjected to cyclic loading in water at 5 Hz, starting with a load of 600 N (5000 cycles), followed by stages of 1000, 1300, 1600, 1900, 2200 and 2500 at a maximum of 20 000 cycles each. Results were analyzed using Kaplan-Meier survival analysis and the Log-Rank test (p = 0.05). The fatigue failure load of ES Net applied in three layers (1617 N ± 371) or in one layer (1499 N ± 306), as well as EXFD applied in 2 mm (1496 N ± 264) or in 1 mm (1434 N ± 372) did not differ significantly (p > 0.05). Control teeth fractured at 1255 N ± 350 (p > 0.05). In the fiber-reinforced groups, restorable fractures were observed in 50%–80%, with only 30% deemed restorable in the control group. The fractures originated mainly at the occlusal contact points and the main crack propagated in the corono-apical direction. No crack origin (primary or secondary) starting from the artificial pre-existing crack was observed in fractured specimens. FRC bases did not improve the fatigue resistance of cracked ETMs, but favorably influenced the failure mode.

Effects of Modified Crown Contour on Periodontal Health

Introduction: The contour of artificial crowns has and continues to be highly controversial. Much of the controversy centers on whether the gingival sulcus is really in need of protection from buccal and/or lingual convexities, or whether a flatter emergence profile affords "self-cleansing" muscle action. Evidence is reviewed in this part which suggests that over-contoured crown is probably more detrimental to gingival health than under-contoured crown. Objective: The purpose of this study was to evaluate the effects of modified crown contour (over-contoured and under-contoured) on periodontal health. Methods: This study was conducted in the department of Prosthodontics, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh for the duration of one and half year to find out the successful artificial crown contour that is harmonious with the periodontium. Selected mandibular molar teeth were prepared for full veneer crown. 50 patients (Group-A) whose full veneer crown was fabricated with under-contouring form and another 50 patients (Group-B) whose full veneer crown was fabricated with over-contouring form and cemented on respected teeth. Clinical examination and evaluation were done after three (3) weeks, six (6) weeks, three (3) months, and six (6) months of post prosthesis follow up period. Data were collected on the basis of following parameters like gingival index, periodontal index, periodontal pocket depth, and gingival recession in a predesign data collection sheet. Statistical analysis (Chi- Square Test and unpaired t-test) was done to find out the significance value (P&lt;0.05). Results: It is observed that the result was highly significant (p&lt;.001) between two groups regarding Gingival index and Periodontal index but not significantly difference regarding Periodontal pocket depth or Gingival recession. Conclusion: This study revealed that under-contoured restoration does not produce any significant changes in the health of gingiva but over-.......

Assessment of Marginal Integrity and Color Stability of Provisional Restoration Fabricated from Different Autopolymerizing Acrylic Resins - A Comparative Study.

Aim:The present study is aimed to assess the marginal integrity and color stability of provisional restorations fabricated from different autopolymerizing acrylic resins.Materials and Methods:Totally, 60 provisional crowns were fabricated. A mandibular first molar artificial typodont was mounted on a base of dental stone. The mandibular first molar which was mounted was prepared for full cast crown, using the tooth preparation standard principles with shoulder finish line of 1 mm and taper 6°. There were 20 samples in each acrylic resin group: Group I: Polyvinyl-ethyl methacrylate resin, Group II: Autopolymerizing bis-acrylic material, and Group III: Polymethyl methacrylate (PMMA) autopolymerizing resin. Crowns were verified for marginal adaptation using stereomicroscope at a ×40. The color stability was measured using spectrophotometer poststaining period.Results:Autopolymerizing bis-acrylic material group showed minimum mean vertical marginal discrepancy (128.68 ± 18.036 μm) followed by PMMA autopolymerizing resin group (147.49 ± 20.128 μm) and polyvinyl-ethyl methacrylate resin group (172.89 ± 22.118 μm). Analysis of variance demonstrated a statistically significant difference between different autopolymerizing acrylic resins. The color change values did not show any significant difference between the groups on numerous comparisons between different autopolymerizing acrylic resin groups. A statistically significant difference was seen between Groups I and II, Groups I and III, and Groups II and III (P < 0.05).Conclusion:This study concluded that the autopolymerizing bis-acrylic material demonstrated significantly improved marginal integrity when compared to PMMA autopolymerizing resin and polyvinyl-ethyl methacrylate resin.