Nor Aidaniza Abdul Muttlib

Post plays a crucial role in reinforcing final restoration in endodontically treated teeth (ETT). The appropriate selection of the post system is crucial for enhancing the clinical success of the restored tooth. This study aims to evaluate the adaptation, fracture resistance, and fracture patterns of ETT restored with different post systems, specifically zirconia posts, cast metal posts (CMP), and anatomically customised fibre-reinforced composite (FRC) posts. Twenty-four human premolars were randomly allocated into four groups. The teeth were root canal treated and prepared to receive zirconia, CMP, and anatomically customised FRC posts. All the samples were subjected to adaptation evaluation, fracture resistance test, and fracture pattern analysis. One-way ANOVA showed a statistically significant difference in mean adaptation between the groups (p < 0.001). Post-hoc Bonferroni analysis suggested that the adaptation values were statistically significant among zirconia and CMP (p < 0.001), and in zirconia and FRC (p = 0.007). Regarding fracture resistance, one-way ANOVA presented a statistically significant difference among the groups (p = 0.001). Post-hoc Bonferroni analysis reported a significant difference in fracture resistance in zirconia and control (p = 0.001), CMP and FRC (p < 0.001), and FRC and control. The categorical analysis of fracture patterns revealed no statistically significant differences among the zirconia, CMP, and FRC post systems. Zirconia posts show lower adaptation than CMP and FRC posts. However, their fracture resistance is comparable to CMPs and FRCs. Fracture patterns were generally consistent across the different post systems; however, the control group exhibited a significantly different pattern, highlighting the influence of post presence on fracture behaviour.

Objectives: Polyamide 12 (PA 12), a widely used thermoplastic polymer, exhibits exceptional mechanical, thermal, and chemical properties, making it a crucial material in various industries, particularly the medical sector. With its semi-crystalline structure and low water absorption, PA 12 offers superior flexibility, impact resistance, and processability. This review explores the advancements and applications of PA 12 in medical fields. Material and Methods: Only articles published in 2013–2024 and written in English were reviewed in this study. An electronic search was conducted in databases such as Google Scholar, PubMed, PubMed Central, ScienceDirect, and Medline with the terms “polyamide,” “polyamide 12,” and “polyamide 12 in the medical field” used. Results: From a pool of 1018 articles initially identified, 211 were deemed relevant to the keywords “polyamide,” “polyamide 12,” and “PA 12 in the medical industry.” Following a screening process focusing on articles published from 2013 to 2024 and reviewing content, only 19 articles met the criteria. Conclusion: PA 12 was found to play a vital role in the medical sector, being used in catheters, tissue engineering, biomedical implants, dental prostheses, and many more.

The traditional approach to fabricating ocular prostheses often requires multiple visits, including impression making, wax pattern try-in, iris coloring, iris button fitting, and final prosthesis delivery. This process can be challenging for patients with logistical difficulties. Additionally, not all clinics offer this service due to limitations in expertise and equipment. This case report aims to present a modified technique for creating ocular prostheses that reduces the number of clinical visits while maintaining the quality of the final result.

Polyamide12 (PA12) has been used to fabricate flexible dentures for patients with prominent undercuts. It has a high moulding property, enabling it to take the shape of the canal without forming any voids, hence a suitable canal space restorative material. This study aims to investigate the chemicomechanical properties of PA12 composite reinforced with crystalline nanocelluloses (CNC) from oil palm fibre (OPF) and rice husk (RH) silica compared to commercial posts. Treated silica from RH and CNC from OPF were incorporated into the PA12 matrix to obtain the samples. Six 1.5 mm × 2 mm × 2.5 mm samples were prepared for seven groups. The flexure test, Fourier-transform infrared spectroscopy, and scanning electron microscopy (SEM) were employed during sample evaluations. A statistically notable variation in flexural strength among the sample groups [χ2 (df) = 38.65 (6)] was observed. The PA12 with CNC fillers recorded increased flexure strength than its unfilled counterpart and no significant difference with the commercial post. The SEM results confirmed the presence of both fillers in the composite. Smoother surfaces with fewer voids and gaps were observed with filler weight percentage (wt%) increments, suggesting enhanced interfacial bonding. Incorporating CNC into the PA12 matrix increased the flexural strength of the composite, whereas silica reduced it. Therefore, within the limitations of this study, new PA12 composites reinforced with CNC fillers from OPF biowastes could be a promising alternative for dental posts. However, additional research is needed to fully assess their viability.

Objective: This study was conducted to assess the influence of combining different forms of fiber-reinforced composites (FRC) on the mechanical behavior and bond strength of compromised endodontically treated teeth (ETT). Materials and methods: Eighty extracted human premolar teeth were randomly divided into five experimental groups according to the type of intra-radicular restoration and the canal preparation design which was either non-flared (Group 1), flared (Groups 2–5), closed-apex (Groups 1,3,5) or open-apex (Groups 2,4). Standard prefabricated fiber posts were used as intra-radicular restoration for Groups 1–3 while Groups 4–5 were restored with anatomically customized relined fiber posts. After composite core fabrication, all samples were sent for an artificial aging process. Fracture resistance and push-out bond strength tests were then carried out through a universal testing machine followed by mode of failure analysis via a stereomicroscope and scanning electron microscope. Results: Pairwise Log-Rank comparisons revealed that the survival rate of Group 2 and Group 3 was significantly lower than all other groups after artificial aging. The highest fracture resistance value (1796 N) was recorded in Group 5 and was significantly higher than that of the other groups (p < 0.05), while Group 2 exhibited the lowest fracture resistance (758 N), which was significantly lower compared to the other groups. Group 5 and Group 4 demonstrated a significantly higher push-out bond strength, at all root thirds, than Group 3, Group 2, and Group 1 (p < 0.05). The most frequently observed failure mode in the tested groups occurred between the resin cement and radicular dentin. Conclusion: The use of short fiber-reinforced composite (SFRC) to reline the prefabricated FRC post has been proven to have superior fracture resistance with favorable failure patterns and increased push-out bond strength values compared to standard prefabricated FRC posts.

Objective. Reviewing oil palm fibre (OPF) utilisation in various medical sectors. Background. The OPF, especially in nanocellulose form, is frequently used due to its exceptional mechanical attributes, considerable surface area, versatility for surface functionalisation, biocompatibility, and nontoxicity. Method. Only articles published in the last ten years (2012-2022) and written in English were reviewed in this study. An electronic search was conducted in Google Scholar, ScienceDirect, and PubMed using the terms oil palm fibres in the medical field and oil palm fibre. Results. Among the 459 articles obtained, only 24 were accessible as full text and satisfied the parameters set in this study. Conclusion. The OPF could be widely employed in the medical domain, particularly the biomedical branch, for drug delivery, tissue engineering, wound dressing, and antimicrobial agent transporters. The substance also demonstrated promising results and significant capacities to be utilised and further studied.

Objective This study aimed to investigate the effect of relining prefabricated fiber-reinforced composite (FRC) posts using bulk-fill, flowable, discontinuous short fiber-reinforced composite (SFRC) on intracanal adaptation in weakened endodontically-treated premolar teeth. Materials and Methods Forty extracted human premolar teeth were selected and randomly allocated to five groups (n = 8) according to the canal preparation method and restorative technique after endodontic treatment: Group 1 (control): nonflared, closed apex root canals; group 2, 4: flared, open-apex root canals; group 3, 5: flared, closed apex root canals. Groups 1 to 3 were restored with standard RelyX fiber post size #1, while groups 4 and 5 were restored with customized RelyX fiber post size #1 and relined with bulk-fill flowable SFRC (everX Flow, GC, Tokyo, Japan). To evaluate intracanal adaptation, the empty root of each sample with the corresponding fiber post (standard or customized) inserted was measured twice using a micro-digital scale and the average value was calculated. The post was then removed, followed by the insertion of a light body polyvinyl siloxane (PVS) impression material into the canal, followed by reinsertion of the post and removal of excess material once the PVS was set. Finally, the sample weight was recorded, and the data were analyzed using one-way analysis of variance and the Bonferroni post hoc test (p-value = 0.05). Results A statistically significant difference (p < 0.05) in PVS material weight was identified between the groups. Group 1 (control) had the lightest weight of PVS material, followed by groups restored with customized fiber posts (groups 4 and 5) and standard fiber posts (groups 2 and 3). Conclusion Anatomically-customized fiber posts with bulk-fill flowable SFRC provided better intracanal adaptation compared with standard fiber posts in teeth with compromised root canals.

The innovation of nanocellulose as reinforcement filler in composites has been a topic of interest in the development of new biomaterials. The objective of this study was to investigate the mechanical properties of a nanohybrid dental composite made of rice husk silica and loaded with different percentages of kenaf nanocellulose. Kenaf cellulose nanocrystals (CNC) were isolated and characterized using a transmission electron microscope (TEM) (Libra 120, Carl Zeiss, Germany). The experimental composite was fabricated with fiber loadings of 1 wt%, 2 wt%, 3 wt%, 4 wt%, and 6 wt% silane-treated kenaf CNC, and subjected to a flexural and compressive strength test (n = 7) using an Instron Universal Testing Machine (Shimadzu, Kyoto, Japan), followed by a scanning electron microscopic assessment of the flexural specimen’s fracture surface using a scanning electron microscope (SEM) (FEI Quanta FEG 450, Hillsborough, OR, USA). Commercial composites Filtek Z350XT (3M ESPE, St. Paul, MN, USA), Neofil (Kerr Corporation, Orange, CA, USA) and Ever-X Posterior (GC Corporation, Tokyo, Japan) were used as a comparison. The average diameter of kenaf CNC under TEM was 6 nm. For flexural and compressive strength tests, one-way ANOVA showed a statistically significant difference (p < 0.05) between all groups. Compared to the control group (0 wt%), the incorporation of kenaf CNC (1 wt%) into rice husk silica nanohybrid dental composite showed a slight improvement in mechanical properties and modes of reinforcement, which was reflected in SEM images of the fracture surface. The optimum dental composite reinforcement made of rice husk was 1 wt% kenaf CNC. Excessive fiber loading results in a decline in mechanical properties. CNC derived from natural sources may be a viable alternative as a reinforcement co-filler at low concentrations.