Crown Restorations Research Articles

Bite force evaluation at maximal intercuspal position: An in vivo comparative study between stainless steel and zirconia crowns on primary molar teeth.

The objective of this study was to clinically evaluate and compare the mean bite force changes at maximum intercuspal position, along with parental satisfaction following full crown restoration using stainless steel crown/zirconia crown on primary molar teeth using digital occlusal analysis system T-Scan III (Tekscan Corp, Boston, Mass., USA). Thirty-six primary molars of children aged 6-9 years with pulpal involvement were selected for the study. The selected teeth were allocated to either of the two groups using simple random sampling technique: Group A = stainless steel crowned teeth and Group B = zirconia crowned teeth. The mean bite force was recorded before the placement of the crown, after the placement of the crown, and after 1 month-follow-up. The inter-group and intra-group comparison was done among the groups. After the placement of the crown, parents were asked to fill out a questionnaire for assessing parental satisfaction. A significant result in the bite force on crowned tooth, vertical dimension was seen from baseline to 1-month follow-up between the SSC and zirconia groups. In the zirconia crown group, the mean bite force was more compared to the stainless steel crown group. Parents' satisfaction was higher with zirconia crown in terms of color and esthetics. SSC is more acceptable than zirconia crown since occlusal re-equilibration was attained better in SSC as compared to zirconia crown.

Impact of Full Veneer Crown Restoration on the Periodontal Health of Posterior Teeth

Background: Periodontal health plays a vital role in the longevity of prosthodontic restorations. Full veneer crown (FVC) is one of the most common modalities in restoration of single tooth for preservation of function and health of oral tissues. Objectives : The study was done to critically evaluate the impact of FVC restoration providing standard procedures on the periodontal health of posterior teeth, also to observe the changes of periodontal health in terms of their status of gingival index, plaque index, periodontal pocket depth, bleeding on probing in different stages of treatment. Materials & Methods: This prospective study evaluated the impact of FVC on periodontal health of 30 endodontically treated posterior teeth with FVC and 30 contralateral natural teeth of 19 patients in different stages of treatment for 2 years duration in the Dept. of Prosthodontics, Bangabandhu Sheikh Mujib Medical University (BSMMU) Hospital. To assess the periodontal health gingival index, plaque index, periodontal pocket depth, bleeding on probing were used. Collected data were analyzed using SPSS software (version 22) according to the study Objectives Results: The study Result showed that the mean differences of gingival index and plaque index between abutments and contraleteral natural teeth were non significant (p > 0.05) at baseline, 4th month visit; but the differences were significant (p < 0.05) at 8th month, 12th month visits. Regarding periodontal pocket depth the mean differences between abutments and contraleteral natural teeth found non significant (p > 0.05) throughout the follow up period. Same thing observed in bleeding on probing except 12th month follow up visit, where highly significant (p < 0.01) mean differences observed. Also the study found that the gingival index, plaque index, bleeding on probing, periodontal pocket depth increased a bit in 4th,8th,12th month visits gradually in abutments, which was almost same in contralateral natural teeth in case of gingival index, periodontal pocket depth; and increased a bit in case of plaque index, bleeding on probing. Conclusion : If the FVC is fabricated maintaining all standard procedures equigingival margin with proper marginal adaptation, oral hygiene as well as general health of the patient is maintained although less but there is a chance of detrimental effects on periodontal health in comparison to contralateral natural teeth. J Bangladesh Coll Phys Surg 2023; 41: 46-52

Comparison the marginal and internal fitness of veneered and anatomical zirconia crowns milled by two different CAD/CAM systems (An in Vitro Study)

Background: Accuracy of fit is considered a very important factor in a crown fabricating procedure. Zirconium oxide ceramic is gaining popularity because of its remarkable mechanical capabilities and the potential aesthetic results obtained by using its recommended veneering porcelain, this study aimed to determine the effect of porcelain veneering on the marginal and internal fitness of zirconium-oxide crowns milled with two different CAD/CAM systems ( Wet and dry milling).
 Materials and methods: An ideal prepared tooth #16 to receive an all-ceramic crown restoration with 0.8mm chamfer finishing line was used as a master die. It duplicated and poured to get thirty-two stone working dies. The stone dies divided into two major groups according to the CAD/CAM systems being used, then each group subdivided into two subgroups (n=8) either zirconia crowns milled to full contour or traditional veneered zirconia crowns. Each crown then cemented to it stone die and sectioned longitudinally into four pieces. Stereomicroscope with aid of (image J) was used to examine the sample at a magnification of (140X). Four points of measurement were selected at each of the four-sectioned parts.
 Results: The final internal gap value of each sample was the arithmetical mean of the selected points of the four-sectioned pieces The data was evaluated statistically, using One-way ANOVA and LSD tests which revealed highly significant differences (p<0.001) among groups.
 Conclusion: Full-contoured zirconia crowns have better marginal and internal fit than the traditionally veneered crown, (CEREC AC, Sirona) system showed the best internal fitness. The mean gap of all groups was within the clinically acceptance.

Periapical Status of Non–Root-Filled Teeth With Amalgam, Composite, or Crown Restorations: A Cross-Sectional Study

ObjectivesThis study aimed to evaluate the periapical status (PAS) of restored non–root-filled (RNRF) teeth amongst a group of patients attending dental teaching clinics at Jordan University of Science & Technology. It also aimed to assess the association of type and quality of coronal restorations and periapical disease. MethodsThis was a cross-sectional study. To be included, participants needed to have at least 1 non–root-filled tooth restored with either direct or indirect restoration. A sample of 491 participants was examined. Clinical examination and digital periapical radiographs were used to record material used and assess the quality of the restorations. Chi-square test and logistic regression analysis were used to analyse the association between PAS and gender, age, restoration material/type, and quality. ResultsOverall, 26.3% of the participants were diagnosed with apical periodontitis (AP) on 1 or more of the examined teeth. No significant differences in the prevalence of AP were observed when comparing amalgam to composite or indirect restorations (P = .386). Furthermore, no association was reported between AP and gender or age, while a significant association was observed with the restoration's quality (P < .001). ConclusionsThe high prevalence of AP in the examined sample is of clinical concern and suggests that more attention should be directed towards dental health awareness in Jordan. Teeth restored with inadequate restorations were twice as likely to have AP.

Implant or Tooth?-A Prospective Clinical Study on Oral Health-Related Quality of Life for Patients with "Unrestorable" Teeth.

In cases of severely compromised teeth, dental practitioners are confronted with the therapeutic decision of whether to restore a tooth or replace it with an implant. Comparative scientific evidence on patient perception of both treatment approaches is scarce. The subject of this prospective clinical study was to compare oral health-related quality of life (OHRQoL) between two treatment groups: restoration of severely destroyed teeth after orthodontic extrusion (FOE) versus tooth extraction and implant-supported single crown restoration (ISC). A self-selected trial was performed with 21 patients per group. OHRQoL was assessed with the aid of the Oral Health Impact Profile (OHIP-G49) at different time intervals: before treatment (T1), after treatment (T2), after restoration (T3) and at recall (T4). Overall, OHIP scores improved from baseline to follow-up for both concepts with no significant differences between groups. There were no significant differences in subscales between FOE and ISC at T1, T3 and T4. In terms of functional limitations (p = 0.003) and physical disability (p = 0.021), patients in the FOE group temporarily exhibited lower OHRQoL at T2 in comparison to the ISC group. However, at baseline, after final restoration and at recall, the study demonstrates the same level of OHRQoL for both treatment concepts.

Zirconia crown restoration on endodontically treated first premolar: A case report

Background: Endodontic treatment failure is frequently caused by insufficient coronal sealing or crown restorations. In the longterm, this reduces the dental prognosis. A widely used restoration material that has outstanding mechanical properties is zirconia. Purpose:This report's aim is to describe the management of zirconia crown restorations on first premolars after endodontic treatment. Case: A 54-year-old male patient complained of a lump in the upper right gum area and had a restoration done, but it frequently came off. The patient needs immediate treatment with a longer-lasting restoration. Case Management: Endodontic treatment was completed in a single visit, and a zirconia crown was used as a permanent restoration Conclusion: Zirconia crown restorations on first premolars after endodontic treatment provide aesthetic and promising results.

Single visit root canal treatment with post crown restoration

Background: Single visit endodontics has been shown to be an effective treatment modality when compared with multiple visit therapy and it does not deviate from achieving the objectives of proper biomechanical preparation, debridement, shaping, disinfection and 3 dimensional obturation of root canal system and is more beneficial to the patient and dentist provided there is careful case selection and strict follow of standard endodontic protocols. Symptomatic teeth can also be managed by single visit after controlling the abscess infection with antibiotic, provided the root canal is dry without any discharge.Purpose: This study aims to perform single visit root canals on teeth with irreversible pulpitis and restoration with post core and crown. Case(s): A 48-years-old female comes with dental complaints of upper left rear spontaneous pain at night. The tooth has had cavities since about two years ago and has never been previously treated. The patient said had not any systematic health disorder. There is a spontaneous pain that the patient feels. Case Management: From the examination that has been carried out, a clinical diagnosis of tooth 25 were symptomatic pulpitis irreversible with normal apical tissue. The restoration endodontic treatment plan was a single visit endodontic and the restoration is post core and crown. Conclusion: Symptomatic pulpitis irreversible with normal apical tissue treatment can be carried out single visit root canal treatment. Restoration of post endodontic treatment in this case need fiber post and core using composite and finally restoration using crown that made of zirconia. Zirconia has a higher level of material resistance than lithium disilicate. This is what makes zirconia the choice, especially for posterior teeth.

Application prospect of polyetheretherketone in postcore crown restorations

Application prospect of polyetheretherketone in postcore crown restorations

The influence of aging on the fracture load of milled monolithic crowns

BackgroundThis in-vitro study was conducted to assess the effect of aging on the fracture load of molar crowns fabricated with monolithic CAD/CAM materials.MethodsThe crown restorations were produced from Cerasmart, Vita Enamic, and IPS e.max CAD blocks. Aging was applied to the 10 samples each of monolithic CAD/CAM materials (n = 10). Dual-axis chewing simulator (50 N, 1.1 Hz, lateral movement: 1 mm, mouth opening: 2 mm, 1,200,000 cycles) and thermocycling (± 5–55 °C, 6000 cycles) were applied as an aging procedure. 10 samples each of monolithic CAD/CAM materials without aging (n = 10) were considered the control group. 6 tested groups were obtained. Then, all samples were evaluated in a universal testing machine to determine the fracture loading values’.ResultsThere was not a statistically significant difference between the fracture load values before and after aging for all samples of Cerasmart, Vita Enamic, and IPS e.max CAD (p > 0.005). In a comparison of the monolithic materials together, a statistically significant difference was found between the fracture load values of IPS e.max CAD and Vita Enamic crowns before aging (p = 0.02). Also, Vita Enamic crowns (1978,71 ± 364,05 N) were found different from the IPS e.max CAD (p = 0.005) and Cerasmart crowns (p = 0.041) after aging.ConclusionsDynamic aging with 1.200.000 cycles was found to have no effect to fracture loading on milled Cerasmart, Vita Enamic, and IPS e.max CAD monolithic crowns.

Endodontic treatment of the maxillary first molar with palatal canal variations: A case report and review of literature

Root canal variations frequently occur in maxillary first molars, which greatly affects the success of its treatment. The second mesiobuccal (MB) root canal is the most common root canal variation. However, only a few studies have been conducted on palatal root canal variations. Herein, we report the presence of two separate root canals in a palatal root of the maxillary first molar. A 39-year-old woman complained of pain in the maxillary right region for 1 year, which recently worsened. Clinical examination revealed a poorly restored right maxillary first molar and caries detected at the filling marginal. Cold and heat test results indicated severe pain in the right maxillary first molar. The patient was diagnosed with irreversible pulpitis, and subsequently, root canal treatment (RCT) was performed. In total, five root canals were found in the maxillary first molar, including two separate root canals in the palatal root. RCT was successfully performed using an endodontic microscope and cone-beam computed tomography (CBCT). The CBCT image revealed a vertucci type I canal morphology in the distobuccal root, while the MB and palatal root canals were type Ⅳ. At the 1-mo follow-up, the maxillary first molar was completely asymptomatic, and the X-ray results indicated a successful RCT. Finally, the ceramic crown restoration was performed. An endodontic microscope and CBCT are useful in effectively identifying and treating root canal variations.

Appropriate Immediate Dentin Sealing to Improve the Bonding of CAD/CAM Ceramic Crown Restorations.

This study aimed to use quantitative and qualitative evaluations based on micro-tensile bond strength (μTBS) to clarify the appropriate immediate dentin sealing (IDS) approach for improving the bonding of CAD/CAM ceramic crown restorations. Forty-eight extracted human molars were prepared to obtain standardized abutment specimens and divided into three groups: no IDS (group C: control), IDS performed by a single application of an all-in-one adhesive system (group A), and IDS performed by the combined application of an adhesive system and a flowable resin composite (group F). All specimens were restored with a ceramic crown fabricated by a chair-side CAD/CAM system and were divided into no-stress and stressed groups. After cyclic loading (78.5 N; total, 3 × 105 cycles; 90 cycles/min) on the specimens in the stressed group, all specimens were sectioned. The μTBS values for the occlusal and mesioaxial walls were measured (n = 16) and analyzed statistically. The quantitative bonding performance of groups A and F were superior to that of group C, regardless of the cyclic loading and abutment wall conditions. Group F showed the maximum bond strength and the highest bond durability in the qualitative bonding performance even under the cyclic loading condition simulating clinical mastication.

A hybrid and hierarchical stated preference study of freshwater restoration in Aotearoa New Zealand

Freshwater quality is multi-dimensional with many interrelated activities, indicators, and demand-relevant values. Environmental managers have a regulatory obligation to invoke social values when deciding on specific restoration activities to fund and must balance values with other criteria. However, it is often difficult to apply non-market values to operational decisions because valuation studies are either not decision-relevant, ecologically irrelevant, incomplete in scope, or not able to be disaggregated to the required spatial scale. This paper describes the design, implementation and results of a stated preference survey strategically positioned to be relevant to freshwater restoration institutions in Aotearoa New Zealand. The study uses a hybrid approach with different measurement methods to measure preferences for crown restoration activities and decompose those preferences by different restoration goals. The recently developed Multiple Discrete-Continuous Nested Extreme Value (MDCNEV) model is used to analyse budget allocation responses. At the most disaggregated level, discrete choice questions are used to evaluate quality and distance trade-offs. The hierarchical approach ensures responses are internally scope-and-scale consistent.

Sodium aluminum silicate composite ceramics with secondary caries prevention for dental crown restoration

Secondary caries caused by plaque accumulation at the edge of crown restorations is still a significant reason for crown restoration treatment failures. To prevent secondary caries, it is urgent to develop dental crown restorative materials with good antibacterial ability and mechanically stable properties. In this work, functionalized dental crown restorations were successfully prepared by doping the human trace element Zn into sodium aluminum silicate ceramics (NAS/Zn). The results demonstrated that the NAS/Zn composite ceramics killed Streptococcus mutans (S. mutans) effectively. The Zn ions released by NAS/Zn composite ceramics disrupted the bacterial membrane integrity and DNA proliferation, promoted the outflow of protein, and eventually led to bacterial death. Most notably, NAS/Zn composite ceramics exhibited excellent biocompatibility. This study will provide a new strategy to prevent the occurrence of secondary caries via the construction of dental crown restorative materials.

A case of precise prosthesis under the direction of target restoration space analysis after multidisciplinary combination therapy.

Quantitative grinding of abutment teeth is needed in crown and bridge restoration. Accurate quantitative preparation of teeth is one of the goals of minimally invasive restoration. In this paper, a case of congenital loss of upper and lower incisors was reported. Guided by the target restoration space (TRS), a personalized digital guide plate for tooth preparation was built to assist precise tooth preparation after the multidisciplinary combination therapy of orthodontic and periodontal teeth. Finally, the fixed bridge was prepared to meet the integrity, beauty, and function of the maxillary for the patient. In this case, the results suggest that the digital guide plate built under the guidance of TRS can be used to improve the accuracy of dental preparation.

Экзогенные причины изменения цвета прямых композитных реставраций зубов

INTRODUCTION: Technological processes of manufacture of dental materials with different manipulation qualities and physicochemical properties, are being constantly improved. Nowadays, a doctor can select the optimal material for each specific clinical case and to achieve the maximal functional and esthetic result. Thus, the most common method of restoration of the tooth crown is direct restoration using composite materials. In the last decade, the demand for conservative restorative dentistry has sharply increased. In turn, esthetic characteristics of composite materials are of key importance both in filling of teeth of the anterior group, and in restoration of the lateral teeth. Discoloration of the dental filling material is a common cause of its replacement. Therefore, to achieve a positive long-term result, it is important to prevent the change of composite color over time. This requires a clear understanding of the causes and conditions of discolorations. AIM: To systematize the scientific data accumulated in recent years concerning the study of the effect of coloring substances of human diet on the aesthetic characteristics of composite materials for direct dental restoration. CONCLUSION: Various pigments present in food and beverages have an effect on composite materials, reducing their microhardness, increasing the rate of wear and changing the color. It depends on the composition of the composite matrix and its chemical structure. Many studies prove that BIS-GMA based composite materials are most susceptible to staining, while UDMA and BIS-EMA matrices, as well as silorane resins, are stained to a lesser extent.

NON-INVASIVE ESTHETIC REHABILITATION OF ANTERIOR DIASTEMA WITH DIRECT COMPOSITE RESTORATION

Diastema is a gap between adjacent teeth that occur physiologically from the teeth eruption. However, diastema between the maxillary central incisors in an adult can be an aesthetic problem and sometimes impair speech. Diastema treatment with low or enlarged superior labial frenulum includes frenectomy, orthodontic treatment, veneers, crown, and bridge or resin-based composite direct restorations. This case report will discuss the rehabilitation of diastema in an aesthetic zone of maxillary central incisors due to low frenulum attachment. It was done by a minimally invasive approach using direct composite restoration, completed within several hours after the study model was analyzed, and much less expensive than other forms of treatment. The protocol involved model analysis, smile design, mock-up, silicon index creation, and composite selection. Patient cooperation and understanding of the limitations are critical to long-term treatment success. The direct composite resin is a fast, simple method yet durable to achieve good improvement of small diastema in the aesthetic zone. And stable after three years.

Cone-beam computed tomography evaluation of the possibility of fabrication of screw-retained implant crowns on maxillary central incisors

BACKGROUND: Immediate implant placement to the fresh socket of the extracted tooth, with immediate loading, is well documented. Dental roots in proximity to the vestibular plate require thorough attention from clinicians. Implants placed close to the vestibular plate often lead to its resorption and gingival recession. Therefore, dental surgeons place implants 23 mm away from the vestibular plate. In turn, prosthodontists plan implant placement so that the screw channel is not on the vestibular surface, which is most significant in the aesthetic area. However, this is not always possible, and there is a conflict between implant placement with proper primary stability and its simultaneous loading with a screw-retained crown.&#x0D; AIM: To conduct radiological assessment of the ideal implant placement for a screw-retained crown.&#x0D; MATERIALS AND METHODS: A total of 120 cone-beam computed tomography (CBCT; 3 groups of 40 people with different root positions) were analyzed. In each group, the possibility of extracting tooth 1.1 and inserting an implant was evaluated in compliance with the protocol for immediate implantation and the possibility to have the screw shaft of the artificial crown on the palatal surface.&#x0D; RESULTS: Group C was defined as the most favorable for immediate implant placement with a screw-retained crown. The least favorable was group N. In total, the screw channel in 40% of the cases was located palatally, 26.6% to the incisal edge, and 33.3% on the vestibular surface.&#x0D; CONCLUSIONS: Careful analysis of CBCT when planning implant-supported restoration in the aesthetic area is an integral part of the treatment. A team approach is required from surgeons and prosthodontists when planning. In a larger percentage of cases, implant-supported prosthetics in the maxillary central incisors involve the use of alternative solutions for the restoration of screw-retained crowns.

Influence of New Sleeve Composite on Fracture Behavior of Anterior Teeth with Flared Root Canals.

We evaluated the fracture strength and failure mode of non-ferrule teeth with flared root canals that were restored using new experimental sleeve composites. Fifty endodontically treated anterior teeth with flared root canals were restored with direct restorations utilizing different techniques. Group A had teeth (non-ferrule) restored using commercialized MI glass fiber post + Gradia Core as core build-up. Group B had teeth (non-ferrule) restored with commercialized i-TFC glass fiber post + sleeve system. In Group C, the teeth (non-ferrule) were restored with an experimental sleeve composite with commercialized MI glass fiber post and Gradia Core. Group D, teeth (non-ferrule), were restored using custom-made tapered E-glass filling post and Gradia Core. Group E, teeth (with ferrule), were restored with commercialized MI glass fiber post + Gradia Core. After core construction, all specimens underwent direct composite crown restoration and were loaded until fracture using a universal testing machine. Average fracture loads were compared, and the failure modes were observed. Group C exhibited significantly greater fracture strength than other groups (p < 0.05). Favorable fracture teeth ratio of group C was more than that of the other groups. Thus, the new experimental sleeve composite could be clinically useful for core construction of non-ferrule teeth.

Comparison of Clinical and Radiographic Results of Single Tooth Implants against Endodontic Treatment with Post and Crown Repair

Introduction: The choice between the two modes of treatment, endodontic treatment and single tooth implants are very different depending on the dentist, design, definition of successful outcomes, evaluation methods, and sample size. The aim of this study was to compare the clinical and radiographic results of single tooth implants versus endodontic treatment with post and crown restoration in patients referred to the School of Dentistry of Islamic Azad University of Isfahan&#x0D; Materials &amp; Methods: In this cross-sectional analytical study in the academic year 2021, 90 (46 females and 44 males) patients after recording demographic information and medical status, during three different time intervals post treatment (under 3 years, 3 to 5 years and Over 5 years) were examined clinically and radiographically (periapical). Outcome of treatment was classified based on clinical and radiographic findings into three categories: successful, surviving and unsuccessful. Data were analyzed using Chi-squared test (α = 0.05).&#x0D; Results: In this study, 60% of women and 40% of men had endodontic treatment and 42.2% of women and 57.8% of men had single tooth implants. There was no significant difference between the treatment outcomes in the studied groups (p value &gt; 0.521). There was no statistically significant relationship between gender and type of treatment as well as gender and treatment satisfaction (p value &gt; 0.05).&#x0D; Conclusion: Considering the preservation of natural teeth, if possible, root canal treatment is the main treatment of choice, otherwise a single-tooth implant can be a good alternative to missing or extracted teeth in terms of successful outcomes.

Guided Tissue Healing by Preformed Anatomical Healing Caps in the Edentulous Ridge: A 2-Year Retrospective Case-Control Study.

The present study evaluated the 2-year changes in soft tissue width after implant placement in healed sites, using two different methodologies to obtain tissue healing: preformed and anatomical abutment caps for customized healing (test) vs conventional healing abutments (control). The null hypothesis was that there would be no difference between the test group and the control group. Patients who suffered from a single-tooth edentulous area in the premolar/molar region were included. Both the standard abutments and the preformed and anatomical abutment caps were immediately screwed on the implants. The final crown restoration was fabricated 3 months later. Primary outcomes (changes in the alveolar soft tissue ridge) and secondary outcomes (testing adverse events and measuring implant/prosthesis survival) were evaluated. Thirty-nine patients (24 women) with a mean age of 57.7 ± 7.1 years (range: 42.6 to 72.8 years) were included. Alveolar widths in both groups showed significant increases from baseline to the 3-month follow-up, with augmentations of 3.6 ± 0.7 mm for the test group and 1.1 ± 0.9 mm for the control group. The gain in soft tissue appeared to be statistically different between the two groups (P < .0001). Contrarily, any subsequent change in width from 3 months to 2 years was negligible and insignificant (< 0.33 mm for both groups). The technique described in the present study encourages the potential for alternative healing based on the guided soft tissue concept, as it either eliminated the need for second-stage surgery or it reduced step-by-step peri-implant soft tissue conditioning, obtaining a tissue contour immediately very similar to that of a final prosthesis.