Do Hall Technique Crowns Affect Intra-arch Dimensions? A Split-mouth Quasi-experimental Non-randomized Feasibility Pilot Study.

Aim and background: The Hall technique preformed metal crowns (HT-PMCs) are allegedly oversized, temporarily altering inter-arch relationships. Intra-arch dimensions and leeway space (LWS) HT effects are unknown. Aim: To study single HT-PMC intra-arch effects and treated tooth dimensional changes. Materials and methods: Split-mouth, quasi-experimental, non-randomized feasibility pilot study. Intraoral scans (iTero II®) were taken preorthodontic separator placement (scan1), immediately post single HT-PMCs (scan2) in 13 children, and 1 month later (scan3) in eight children. Control and study quadrants' lengths ("arcs") and HT-PMCs/control tooth dimensions [mesiodistal (MD), buccopalatal/lingual (BP/L), diagonal (Diag1/Diag2)] were recorded in mm (OrthoCAD® software). Paired t-test, repeated analysis of variance (ANOVA) post hoc analysis statistics (p < 0.05). Results: Compared to scan1, the mean study arc increased by 0.7 mm (±0.5) (n = 13, t-test, p < 0.001) at scan2, while at scan3, it increased by 0.8 mm (±0.34) (n = 8, repeated ANOVA, p = 0.008). The HT-PMCs-treated tooth mean dimensions increased at scan2 by 0.9 mm (MD), 0.8 mm (BP/L), 0.5 mm (Diag1), and 0.7 mm (Diag2) (t-test, p < 0.001) with similar observations at scan3. There were no significant changes in the control arc or the control tooth measurements. Conclusion: One single HT-PMC increased the intra-arch quadrant length by approximately up to <1 mm. The HT-PMC-treated tooth was marginally oversized. This pilot study paves the way for a more robust study with a larger sample size. How to cite this article: AlRamzi B, AlHalabi M, Kowash M, et al. Do Hall Technique Crowns Affect Intra-arch Dimensions? A Split-mouth Quasi-experimental Non-randomized Feasibility Pilot Study. Int J Clin Pediatr Dent 2024;17(6):673-682.

Of the article: evaluation of the masticatory efficiency of children with stainless steel crowns: a pilot cross-sectional split-mouth study.

BACKGROUND: Stainless steel crowns (SSCs) are commonly employed to restore the posterior teeth of children and over the years, they are available with improved anatomical shapes. This study was conducted to evaluate and assess the effect of the placement of SSCs on the masticatory efficiency of children. METHODS: This pilot cross-sectional split-mouth study assessed masticatory efficiency in children aged 6-11 years. Fifteen participants, each with stainless-steel crowns placed unilaterally at least one month prior, were included. This study utilized two flavours of trident chewing gum (red and green) to measure masticatory efficiency. The child was asked to chew half a strip of red and green chewing gum placed one on top of the other using either the noncrown or crown side 15 times. Another set of chewing gum was given to the child to chew 20 times on the same side. The chewing exercise was repeated using teeth on the other side. Chewed gum samples were collected, photographed, and analysed via ImageJ software to determine the red and green areas. Masticatory efficiency was subsequently calculated with the help of a formula in which the red areas and green areas were calculated via ImageJ software. The data were analysed with paired t tests via SPSS (version 20.0). RESULTS: When the mean values of the crown side were compared with those of the noncrown side following 15 chewing cycles, the chewing efficiency on the noncrown side was greater, with a difference of 0.303, whereas the chewing efficiency following 20 chewing cycles was greater on the crown side, with a difference of 0.814. However, both differences were statistically nonsignificant, with t values of -0.07 and 0.26, respectively, and p values of 0.94 and 0.8, respectively. CONCLUSION: The presence of SSCs on the molars of children did not affect masticatory efficiency.

Evaluation of Nickel and Titanium Releasing from Titanium-coated Stainless Steel Crowns Regarding Trimming: An In Vitro Study.

Introduction: Stainless steel crowns (SSCs) are the most durable and effective restorations for primary teeth. Titanium-coated SSCs are newer on the market, and this study was conducted to assess the amount of nickel (Ni) and titanium ions released from titanium-coated SSCs, with and without trim, in artificial saliva. Materials and methods: A total of 60 titanium-coated SSCs were divided into two groups-group I (n = 30, without trim) and group II (n = 30, with trim) and were immersed in 5 mL artificial saliva. The amount of Ni and titanium released in each group was measured by inductively coupled plasma-mass spectrometry on days 1, 7, and 21. Results: The amount of Ni ion released in group I on day 1 was 0.0096 ppm and reduced on day 7 (0.0091 ppm) and day 21 (0.0088 ppm). Whereas the amount of Ni ion released in group II was the same for all 3 days (0.0096 ppm). The amount of titanium ion released in both groups was the same on all 3 days (0.00108 ppm). Conclusion: There was no significant difference seen in the mean Ni and titanium ion release between the two groups on all 3 days. The cumulative release of metals from titanium-coated SSCs in each of the groups was significantly lower than the level required to produce any harmful effects. Any of the groups of commercially available SSCs can be used in pediatric dentistry. How to cite this article: Biradar R, Siaddaiah SB, Bhat PK. Evaluation of Nickel and Titanium Releasing from Titanium-coated Stainless Steel Crowns Regarding Trimming: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(5):524-527.

The Hall technique: knowledge, practice, and concerns of dentists in primary care settings in the State of Qatar-a questionnaire-based survey.

PURPOSE: To assess the knowledge, practice, and concerns about the Hall Technique among pediatric dentists (PDs) and general dental practitioners (GDPs) working in primary care settings in the State of Qatar. METHODS: A prospective questionnaire-based survey was distributed to all GDPs and PDs working at different Primary Health Care Corporation centers in Qatar between 1 November and 10 December 2023. Descriptive data analysis was carried out. RESULTS: The response rate was 49% among GPDs and 100% among PDs. Approximately 85% of PDs and 48% of GDPs were familiar with the HT although only 58% of the PDs and 4% of the GDPs applied HT preformed metal crowns (HTPMCs) in their current primary care practice. Majority of both PDs and GDPs did not consider HTPMCs as the treatment of choice for restoring asymptomatic carious primary molars and preferred applying the HT for cavitated carious lesions over non-cavitated lesions. Regarding HT practices, 57.7% of PDs and 48% of GDPs always planned on taking a pre-operative radiograph before the procedure, while only 15.4% of PDs and 8% of GDPs would always consider using an orthodontic separator prior to placing an HTPMC. The main concerns among the respondents about the HT included sealing in caries (PDs 31%; GDPs 50%), high occlusion (PDs 57.7%; GDPs 53.3%), and gingival damage (27% PDs; 47% GDPs.) Endorsement by professional bodies and further research evidence were seen as ways to promote wider adoption of the HT. CONCLUSION: The HT is recognised but not widely used among primary care dentists working in the State of Qatar. HTPMCs are often seen as secondary options for restoring carious primary molars with dentists still having a number of concerns regarding the HT.

The Role of Digital Facebow for CAD/CAM Implant-Supported Crowns Workflow.

Recent advancements in digital technologies have transformed clinical workflows in dentistry, ensuring precise restorations. Custom-made crowns and fixed partial dentures (FPDs) now rely on virtual articulation. The digital facebow provides individualized data for CAD settings, streamlining the fabrication via digital workflow. For the purpose of demonstrating the differences observed during fabrication, we present a case report involving a 68-year-old patient seeking a replacement for missing teeth 24, 25, 26, and 27. The treatment plan involved the fabrication of an implant-supported FPD using monolithic zirconia (ZrO2). However, technical hurdles emerged during the planning phase, primarily due to spatial limitations posing a risk of mechanical failure over time. Consequently, we pivoted approach towards a porcelain fused to metal (PFM) FPD. For the PFM FPD, individual values from the digital facebow adjusted both virtual and conventional articulators. For comparison, two ZrO2 FPDs were milled-individual settings and average settings. All restorations underwent assessment for occlusion in maximal intercuspal position and eccentric mandible movements. In conclusion, the case report showed that individualized PFM FPD required minimal adjustments compared to milled ZrO2 restorations, whether using individual or average values. Utilizing individual values from the digital facebow reduced operator working time and minimized the intraoral adjustments.

Use of Computer Digital Techniques and Modern Materials in Dental Technology in Restoration: A Caries-Damaged Smile in a Teenage Patient.

Prosthodontic treatment of developmental age patients presents a significant challenge to the dentist. The growth and development of the stomatognathic system must be considered in treatment planning. Temporary prosthetic restorations must be regularly inspected and recemented, and final prosthetic restoration should not be delivered until the growth of the body is complete. In addition, due to the complex nature of morphological and functional disorders during the developmental period, simultaneous prosthetic and orthodontic treatment may be required. The case presented in this article is a 16-year-old boy with severe tooth destruction caused by untreated caries disease and poor oral hygiene. The patient required conservative, endodontic, and surgical treatment to restore the occlusion and aesthetics to allow the proper development of the masticatory organ. This article also presents the treatment case of a young patient with damaged crowns in the upper arch, which were restored with standard root-crown posts and cores and temporary 3D-printed composite crowns.

Evaluation of the Marginal Fit of Virgilite Based Lithium Disilicate Ceramic Crowns: An In-Vitro Comparative Study.

Background: Achieving optimal marginal fit is essential for the success of Virgilite Based Lithium Disilicate Ceramic crowns. Materials and Methods: In this in-vitro study, we compared the marginal fit of Virgilite Based Lithium Disilicate Ceramic crowns using two different CAD/CAM scanners, powder free (System A, Omnicam) and powder based (System B, Blue cam). Results: The mean marginal gap for System A was found to be 63.5 µm (standard deviation ± 10.2 µm), while for System B, it was 57.8 µm (standard deviation ± 9.8 µm). System B demonstrated a slightly superior marginal fit compared to System A, with a difference of 5.7 µm. Conclusion: Within the limitations of this study, it can be concluded that both Omnicam and Blue cam produced clinically acceptable marginal fit of Virgilite Based Lithium Disilicate Ceramic crowns. However, Blue cam exhibited a slightly better marginal fit compared to Omnicam. Further clinical studies are warranted to validate these findings.

The Effectiveness of Zirconia Crowns Versus Metal Crowns in Anterior Teeth: In vitro Study.

Background: The selection between Zirconia crowns and metal crowns for anterior teeth restorations is pivotal in prosthodontics due to their distinct properties. However, a comprehensive investigation into their effectiveness in anterior tooth restorations is warranted. Materials and Methods: This in vitro study aimed to compare the effectiveness of Zirconia crowns and metal crowns in anterior teeth restorations. A total of thirty extracted human maxillary central incisors were prepared to receive crowns and randomly allocated into two groups: group A, zirconia crowns; and group B, metal crowns. The crowns were fabricated following standardized protocols and cemented onto the prepared teeth. Various tests, including fracture resistance, marginal adaptation, and color-matching assessment, were conducted on the samples. Results: The mean fracture resistance of Zirconia crowns (Group A) was determined to be 320 N (SD ± 25), whereas it was 280 N (SD ± 30) for metal crowns (Group B). Marginal adaptation assessment revealed a mean gap width of 50 microns (SD ± 10) for Zirconia crowns and 70 microns (SD ± 15) for metal crowns. Evaluation of color matching showed a higher percentage of acceptable matches for Zirconia crowns compared to metal crowns. Conclusion: Zirconia crowns exhibited superior fracture resistance, marginal adaptation, and color matching in comparison to metal crowns for anterior teeth restorations. These findings advocate for Zirconia crowns as a more effective choice for restoring anterior teeth, offering both strength and esthetic appeal.

Clinical performance of implant-assisted removable partial dentures using implant surveyed crowns: a systematic review and meta-analysis.

PURPOSE: This study aimed to evaluate the clinical performance of implant-assisted removable partial dentures (IARPD) with surveyed crowns, also known as implant-crown-retained removable partial dentures (ICRPDs). MATERIALS AND METHODS: Electronic searches of MEDLINE/PubMed, the Cochrane Central Register of Controlled Trials, the Web of Science, and the Korea Citation Index were performed according to the established search terms for ICRPD. A literature search was conducted for studies published in English or Korean until September 2023, using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. RESULTS: A total of 216 journals were searched, and 31 eligible studies were selected based on the inclusion and exclusion criteria. One systematic review included five case reports of ICRPD. Nine retrospective studies evaluated implant survival/success rate, implant failure cases, marginal bone loss, periodontal status, clinical complications, and patient satisfaction. Twenty-one case reports published in Korea showed good prognoses. CONCLUSION: According to the findings of this systematic review, ICRPD has a reasonable survival/success rate, minimal bone loss, and high patient satisfaction.

Efficacy evaluation of zirconia crown on primary molars with caries defects.

OBJECTIVES: This study aimed to estimate the therapeutic effects of preformed metal crown (PMC) and prefabricated zirconia crowns (ZC) on decayed primary morals in children, as well as to analyze the possible influencing factors. METHODS: A retrospective cohort study was performed on the data of 192 patients (aged 3 to 8) in the Stomatological Department of Shenzhen Children's Hospital from October 2021 to December 2021. The decayed mandibular first molars were selected and restored by vital-pulp therapy followed by PMC and ZC, including 96 cases (96 caries) in the PMC group and 96 cases (96 caries) in the ZC group. Oral clinical examination was performed at 3 months, 1 year, and 2 years after treatment, overwiewing the clinical therapeutic effects and periodontal status of PMC and ZC groups, as well as recording the crown integrity, gingival index (GI), probing bleeding index (BI), plaque index (PLI) and various prosthetic indices. RESULTS: No significance differences existed in the periodontal status of PMC and ZC groups at 3 months, 1 year, and 2 years after treatment (P>0.05). However, the GI, BI, and PLI in the PMC group were higher than those in the ZC group at 3 months, 1 year, and 2 years after treatment, and the difference was dramatically significant (P<0.05). No significances difference existed in various prosthetic indices (P>0.05), as well as in the GI, BI, and PLI, between the two groups (P>0.05). No significant differences existed in various prosthetic indices between genders after PMC restoration (P>0.05). The scores of girls in various prosthetic indices after ZC restoration were higher than those of boys (P<0.05). Pearson correlation analysis indicated an inverse correlation between age in the PMC group and the GI, BI, PLI, and FDI indices (P<0.01), rather than in the ZC group (P>0.05). CONCLUSIONS: PMC and ZC can be applied to restore deciduous molar caries. The periodontal status of deciduous teeth in ZC group was superior to that in the PMC group. The periodontal status of deciduous teeth in PMC group may be stable with increased age.

An Invitro Study to Evaluate the Retentive Properties of Metal Crowns on Various Surface Roughnesses of Abutments.

Background Restorative dentists frequently deal with the prosthesis coming loose after placing multiple crowns. The luting cement holds indirect restorations to the prepared tooth. However, the success of the restorations is impacted by mastication pressures and other undesired factors. Therefore, escape is required to increase the crown's life. Mechanical locking of the prepared tooth surface is one technique to address this issue, in addition to cement adherence, to extend the life of the restoration. Aims and objective The objective of the study was to evaluate the influence of surface roughness of prepared teeth on the retention of metal crowns. Methodology This in-vitro investigation was carried out on freshly extracted maxillary first premolars that were defect-free and had the same crown size. Using multiple grifts of varied coarseness, different surface roughness was created, allowing for the observation of an important factor like retention (black at 180-250 µm [micrometer], blue at 125-150 µm, green at 106-125 µm, red at 53-63 µm, yellow at 20-30 µm). Results IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp. was used to perform the statistical analysis. Compounds were done before it began to guarantee that the study would have 80% power. There is a mean and a standard deviation for each quantitative variable. A one-way ANOVA was used for quantitative variables, and Tukey's post hoc analysis was conducted afterward. A probability value of less than 0.05 was used to determine statistical significance. According to the statistical findings, the prosthesis's retentive qualities improve as coarseness increases. Conclusion The resistance and retention form of the preparation is critical to the longevity of the prosthesis, based on the findings of the previously described study. Surface roughness, pins, slots, grooves, and other preparation modifications can enhance retention on the prepared tooth surface. The research findings indicate no need to polish the prepared tooth surface.

Influence of build direction, post-polymerization time, and aging on the fracture resistance and marginal and internal discrepancies of three-dimensional printed provisional crowns.

To evaluate the effect of build direction, post-polymerization time, and aging on the fracture resistance, failure mode, margin quality and Marginal (MD) and Internal Discrepancies (ID), and degree of conversion of tridimensional (3D) printed provisional crowns using the liquid crystal display technique (LCD). A left mandibular first molar was prepared and scanned. After, a full crown was designed (ExoCad) and exported to the LCD-printer software. One hundred and eighty crowns were printed at two build directions (30°, 90°) and post-polymerized for different periods (15, 30, 45 min). Half of the samples were aged (ST) in distilled water (37 °C/90 days). The marginal quality of the crowns was evaluated by the Schriwer method under a stereomicroscope (40x). The replica technique was used to measure the MD and ID and measured under a stereomicroscope (10x), through 20 reference points defined in 5 regions: Occlusal (O), Cusp (CP), Axial (AX), Chamfer (CH), and Finish Line (F). After, the crowns were cemented onto the respective dies using temporary cement and submitted to compression test (ISO150, 1 mm/min, 100 kgf).The failure mode was classified by Burke's fracture mode. The degree of conversion was evaluated through Fourier Transform Infrared Spectroscopy. The data (µm) of MD and ID and fracture resistance (N) were subjected to ANOVA (3 factors) and Tukey's test (5%); Weibull analysis was also performed for fracture resistance data (N). For MD, ID and fracture resistance ANOVA revealed that all factors (P < .001) were significant. For aged groups, the crowns printed at 30° showed lower MD (Tukey). The O_90_30 min (172.13A µm) and O_90_15 min (170.20A µm) groups showed the highest ID values. Higher resistance values were observed for the 30_45 min (844.30A N), 30_30 min (835.35A N), and 90_30 min (820.62A N) groups (Tukey). In the margin analysis, 98.6% of the crowns printed at 30° showed smooth margins without defects. The most prevalent fracture mode (41.7%) was Burke type 5. The degree of conversion (DC) increased with increasing post-polymerization time and aging. Printing provisional crowns at 30° provided lower crown MD and ID, as well as higher fracture resistance. A post-polymerization time of 30 min resulted in higher crown fracture resistance, while aging reduced the resistance of the crowns.

The Surface Deterioration of Prefabricated Zirconia Crowns on Exposure to Acidulated Phosphate Fluoride Gel: An In Vitro Study.

Introduction Zirconia is a widely used restorative material in dentistry due to its superior aesthetic and mechanical properties. The oral cavity is a complex ecosystem with various components, which affect the teeth, as well as artificial restorative materials. Various personal and professional interventions carried out can severely affect the properties of restorative materials, thus altering the longevity of the prosthesis; 1.23% acidulated phosphate fluoride (APF) gel is one such professionally applied topical fluoride agent used to prevent caries. The interaction of this APF gel with highly aesthetic restorative material such as zirconia crowns is unknown. Objective The objective of this study is the evaluation of the surface deterioration of prefabricated zirconia crowns on exposure to deionised water and 1.23% acidulated phosphate fluoride (APF) gel with field emission scanning electron microscope (FE-SEM) and mass loss analysis. Material and method Sixty prefabricated paediatric zirconia crowns were taken, 10 samples were immersed in deionised water, 40 samples were immersed in 1.23% APF gel and 10 samples were used as control. Surface morphology and mass loss analysis were carried out at time intervals of four minutes, 24 hours, 48 hours and 72 hours using FE-SEM and digital weighing machine. Results No visual change was observed in the samples immersed in deionised water at the time interval of 72 hours. There was a marked visual change in samples immersed in 1.23% APF gel at the time interval of four minutes to 72 hours; this change involved a loss of gloss to the appearance of chalkiness. FE-SEM analysis for the control group and samples immersed in deionised water showed a smooth, continuous, undisrupted top layer, while samples immersed in 1.23% APF gel showed changes ranging from surface etching, to pinhole porosities, to crack formation and disruption of the surface depending upon the exposure time. Conclusions On the immersion of zirconia crowns in an aqueous acidic medium of 1.23% APF gel, the crowns showed flaws, imperfections and uneven superficial layers. It has been observed that surface grains are disrupted and micropores have been formed. This degraded superficial surface when undergoes cyclic mechanical loading can accelerate the ageing phenomenon of zirconia. Mechanical forces along with a dynamic electrochemical environment can degrade the material properties of zirconia.

Evaluation of Microleakage Using Different Luting Cements in Kedo Zirconia Crowns: An In Vitro Assessment.

Introduction A space between the prepared tooth and the cemented crown can cause microleakage, allowing microorganisms to enter, which in turn leads to the breakdown of the luting cement. To achieve an optimum fit, several factors should be considered, including the type of crown used, the taper of tooth preparation, and the type of cementing agent. Aim The purpose of the current study is to evaluate the microleakage of zirconia crowns cemented with glass ionomer cement (GIC), resin-modified GIC (RMGIC), and self-adhesive resin cement. Materials Forty-five primary mandibular molars were divided into three groups: Group I receiving GIC, Group II receiving RMGIC, and Group III receiving self-adhesive resin cement. These cements were used to lute the teeth with Kedo zirconia crowns. The restored samples underwent thermal cycling and were assessed for microleakage under a stereomicroscope. For the statistical analysis, SPSS version 23.0 was used. Descriptive statistics were presented as frequencies and percentages. Analytical statistics, including the Mann Whitney U test, were used to assess the differences in the level of microleakage between the groups at p < 0.05. Results The Mann Whitney U test revealed no significant difference in the level of microleakage between GIC and RMGIC (p = 0.072). However, self-adhesive resin cement showed significantly less microleakage than GIC (p = 0.000). Similarly, when comparing RMGIC and self-adhesive resin cement, the latter showed significantly less microleakage than the former (p = 0.001). Conclusion Microleakage of Kedo zirconia crowns on mandibular first molars was highest when luted with GIC, followed by RMGIC, and was least when luted with self-adhesive resin cement.

Fit comparison of interim crowns manufactured with open and proprietary 3D printing modes versus milling technology: An in vitro study.

OBJECTIVES: This study aimed to assess the fit of interim crowns produced using DLP-based 3D printing with different manufacturing workflows-open and proprietary-versus milling technology. METHODS: A total of 120 crowns were evaluated using the replica technique. The control group (Mill, n = 30) was manufactured via subtractive technology. Experimental groups were printed using a DLP printer (SprintRay Pro95). In the proprietary mode (SR100, n = 30), manufacturer resin was used with a 100-µm layer thickness (LT) and a splashing cleaning postprocessing. In the open mode, validated resin was used. Group B100 (n = 30) had a 100-µm LT, and group B50 (n = 30) had a 50-µm followed by postprocessing in an ultrasonic bath with full immersion in isopropyl alcohol. Kruskal-Wallis tests with Bonferroni correction was applied after normal analysis (α = 0.05). RESULTS: Group B50 exhibited the best overall fit (123.87 ± 67.42 µm), which was comparable to the gold standard Milling group, which demonstrated the lowest marginal fit (p = 0.760). SR100 showed significantly poorer performance compared to Mill, B50, and B100 (p < 0.001). CONCLUSIONS: 3D printed and milled interim crowns generally demonstrated clinically acceptable fit, with the exception of the SR100 group. Postprocessing notably influenced crown fit, with the open mode with total immersion in isopropyl alcohol being superior. CLINICAL SIGNIFICANCE: The present study demonstrates that the selection of an optimal manufacturing and postprocessing workflow results in superior fit for interim crowns. This enables dental professionals to evaluate protocols and ensure reliable outcomes with improved clinical outcomes in interim crown fabrication.

Interdisciplinary Delphi study by PROSEC North America: Recommendations on single indirect restorations made from ceramic and nonmetallic biomaterials for posterior teeth.

OBJECTIVE: This article puts forward consensus recommendations from PROSEC North America regarding single indirect restorations made from ceramic and nonmetallic biomaterials in posterior teeth. OVERVIEW: The consensus process involved a multidisciplinary panel and three consensus workshops. A systematic literature review was conducted across five databases to gather evidence. The recommendations, informed by findings from systematic reviews and formulated based on a two-phase e-Delphi survey, emphasize a comprehensive treatment strategy that includes noninvasive measures alongside restorative interventions for managing dental caries and tooth wear. The recommendations advocate for selecting between direct and indirect restorations on a case-by-case basis, favoring inlays and onlays over crowns to align with minimally invasive dentistry principles. The recommendations highlight the critical role of selecting restorative biomaterials based on clinical performance, esthetic properties, and adherence to manufacturer guidelines. They emphasize the importance of precision in restorative procedures, including tooth preparation, impression taking, contamination control, and luting. Regular follow-up and maintenance tailored to individual patient needs are crucial for the longevity of ceramic and nonmetallic restorations. CONCLUSIONS: These PROSEC recommendations provide a framework for dental practitioners to deliver high-quality restorative care, advocating for personalized treatment planning and minimally invasive approaches to optimize oral health outcomes. CLINICAL SIGNIFICANCE: The PROSEC North America recommendations highlight the importance of minimally invasive techniques in posterior tooth restorations using ceramic and non-metallic biomaterials. These principles prioritize tooth structure conservation and personalized treatment planning, essential for enhancing clinical outcomes and long-term oral health.

Bacterial Adhesion in Pediatric Crowns: A Systematic and Meta-Analytical Review.

Stainless steel crowns (SSC) have long been the standard choice due to their durability, ease of use, and cost-effectiveness. Other esthetic crowns, known for their superior esthetic properties and biocompatibility, have emerged as a popular option in recent years. A comprehensive literature search was conducted across multiple databases, including PubMed, Scopus, and Cochrane Library, up to June 2024. The population under study was primary teeth, with the intervention being the application of aesthetic crowns. These were compared against SSC, with the primary outcome being the level of microbial adhesion on the crowns in primary teeth. Data extraction and quality assessment were performed independently by two reviewers. Meta-analyses were conducted using random-effects models to estimate pooled differences in microbial adhesion levels. A total of five studies were included in the review. The meta-analysis revealed a statistically significant difference in microbial adhesion between esthetic and SSC, with esthetic crowns showing lower levels of bacterial colonization. Specifically, the mean difference in colony-forming units (CFU). Esthetic crowns exhibit significantly lower microbial adhesion compared to SSC in pediatric patients, suggesting a potential advantage in reducing the risk of secondary caries and other microbial-related complications. However, further long-term clinical studies are warranted to confirm these results and assess their clinical implications.

Comparative Evaluation of Polymethyl Methacrylate and Thermoforming Crowns as Semipermanent Crowns in Primary Molars: An In Vivo Study.

Aim: The present randomized clinical trial is aimed at evaluating clinical efficiency of two different types of esthetic crowns-polymethyl methacrylate crowns and vacuum formed thermoformed crown as an alternative to full-coverage coronal restoration for deciduous molars. Materials and methods: A total of 45 primary molars in pediatric patients were selected using randomization and split into three groups based on the technique used for preparation of crowns: group I-polymethyl methacrylate crowns; group II-thermoformed crown; and group III-stainless steel crowns (SSC). All crowns were clinically and radiographically evaluated at baseline, 1st month, and 3rd month for gingival health, retention, marginal integrity, proximal contacts, occlusion, alignment, and staining. Statistical analysis: The data was tabulated and analyzed by Statistical Package for the Social Sciences (SPSS) Version 23.0 software. The intergroup comparison was done by Kruskal-Wallis test, analysis of variance (ANOVA), and Mann-Whitney U test for continuous data. The intragroup comparison was done by Friedman test and Wilcoxon signed-rank test for categorical data. All p-values < 0.05 were considered statistically significant. Results: With regard to the parameters of plaque score, gingival index score, occlusion, interproximal contacts, retention, alignment, and marginal adaptation, no statistical significance was noted between the three groups. However, with regard to the discoloration (staining) when the polymethyl methacrylate acrylic (PMMA) group was compared with thermoforming group, statistical significance was noted in 1st month with p-values of 0.04 and 0.03, respectively. On intragroup comparison, statistically significant values were obtained in SSC group for plaque score and thermoforming group for gingival index score. Clinical significance: The study concluded that the PMMA and thermoforming crowns can be used as an alternative to SSC for restoring the primary molars as they showed equivalent results to that of standard SSC. How to cite this article: Matha N, Kumar KS, Reddy BVT, et al. Comparative Evaluation of Polymethyl Methacrylate and Thermoforming Crowns as Semipermanent Crowns in Primary Molars: An In Vivo Study. Int J Clin Pediatr Dent 2024;17(S-1):S43-S54.

Fracture Resistance of Zirconia Surveyed Crowns With Digitally Designed and Hand-Modified Occlusal Rest Seats.

Background In light of the trend of using zirconia crowns, clinicians will likely face abutment included in removable partial dentures (RPD) designs with existing zirconia. However, the decision to replace the existing crown with a surveyed crown or modify the existing crown to accept the RPD is unclear. To the best of our knowledge, there is a lack of literature on the effect of preparing a rest seat on the existing monolithic zirconia crown in the patient's mouth on the fracture resistance of the crown. Therefore, in this study, we aimed to evaluate the fracture resistance of computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia surveyed crowns with digitally designed rest seats and hand-modified rest seats. Methods Thirty CAD/CAM zirconia surveyed crowns were digitally designed and fabricated and divided into groups (n=10 per group) as follows: Group 1 comprised surveyed crowns with no occlusal rest seat; Group 2 comprised surveyed crowns with a digitally designed mesial rest seat; and Group 3 comprised surveyed crowns with a hand-modified mesial rest seat. Then, with all the crowns cemented to metal dies, the specimens were subjected to a fracture resistance test using a universal testing machine (Model 8501 Instron, Norwood, MA, USA). Results Surveyed crowns without any rest seat and those with digitally created and hand-modified rest seats displayed different fracture resistances: crowns with no rest seat offered the highest fracture resistance (5831 ± 895.15 N), followed by those with a digitally designed and milled rest seat (5280 ± 1673.33 N). Crowns with a hand-modified rest seat provided the lowest fracture resistance (4976 ± 322.5 N). Based on our results, surveyed crowns without a rest seat displayed higher fracture resistance than those with a rest seat. Conclusion The fracture resistance of crowns with a digitally designed and milled rest seat was statistically similar to that of control crowns with no rest seat, whereas hand-modified rest seats significantly reduced the fracture resistance of surveyed zirconia crowns.

Comparative Evaluation of Microbial Adhesion on Provisional Crowns Fabricated With Milled Polymethyl Methacrylate (PMMA) and Conventional Acrylic Resin: A Prospective Clinical Trial.

Introduction Provisional prosthetic restorations play a crucial role in dentistry by protecting dentinal tubules, offering thermal insulation, and ensuring a precise fit during dental treatments. Computer-aided design and computer-aided manufacturing (CAD/CAM) have improved polymethyl methacrylate (PMMA), enhancing its mechanical properties such as hardness and resistance compared to traditional methods. However, bacterial accumulation remains a challenge due to inherent surface roughness. This study aims to assess and compare Streptococcus mutans adhesion on milled PMMA and conventional self-cure acrylic resin, providing insights into their microbial interaction dynamics. Materials and methods This study was a prospective trial approved by the Institutional Human Ethical Committee (SRB-IHEC) (registration number: IHEC/SDC/PROSTHO-2104/24/045) and registered in the Clinical Trial Registry, India (registration number: CTRI/2024/05/068196). The study involved 20 patients requiring single crowns in the right and left molar regions. Two groups were established: Group I (the milled PMMA group) and Group II (the conventional PMMA group). Criteria for participant selection and exclusion were set. A total of 120 swab samples from the buccal mucosa and tooth surfaces were collected before tooth preparation (the baseline) at one week and three weeks. Culture for S. mutans was done, and colony-forming units were counted. Data analysis was carried out using IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York, United States). An independent sample t-test was employed to compare the two materials for crowns. To analyze changes over time within each group, a repeated-measures analysis of variance (ANOVA) was conducted. When the ANOVA test indicated significance, Tukey's post-hoc test was utilized for pairwise mean comparison. The level of significance was set at P < 0.05. Results The mean colony-forming units (CFU) counts for the milled PMMA group were 4.46 ± 0.167 CFU at baseline, 4.163 ± 0.058 CFU at one week, and 3.87 ± 0.19 CFU at three weeks. The mean CFU counts for the conventional PMMA group were 4.41 ± 0.13 CFU at baseline, 4.29 ± 0.114 CFU at one week, and 4.16 ± 0.108 CFU at three weeks. At baseline (before cementation), there was no difference between milled PMMA and conventional PMMA (P = 0.578). After one week, a significant difference between milled PMMA and conventional PMMA was observed (P < 0.005). After three weeks, a significant difference between milled PMMA and conventional PMMA persisted (P < 0.005).  Conclusion There was a significant reduction in microbial adhesion in both the milled and conventional PMMA groups. However, milled PMMA demonstrated a greater decrease in microbial adhesion as compared to conventional PMMA.