The Journal of Indian Prosthodontic Society最新文献

Aim: To validate the CBCT classification for immediate implant placement (IIP) given by Howard Gluckman in the local population of Gujarat, India, and additionally evaluate the available bone beyond the tooth apex for IIP in the direction of proposed osteotomy.

Setting and design: Cross-sectional Observational study.

Materials and methods: A total of 103 cone beam computed tomography (CBCT) scans involving the six maxillary anterior teeth were scrutinized in the radial plane. Each CBCT was divided into six slices (n = 618), which were classified according to Gluckman's classification, followed by making the osteotomy lines. Six measurements (L, W1, W2, W3, W4, and W5) were made from root to nasal floor. Bone length (L) was measured in the direction of proposed osteotomy, whereas the bone width was measured at five different points along the proposed osteotomy.

Statistical analysis used: Chi-square p value, One-way ANOVA and Post hoc Tukey test.

Results: As per Gluckman's classification, it was found that class I showed the highest bone width with the lowest bone length, whereas Class V showed the lowest bone width. The highest bone length was observed in Class IV. The prevalence of different radial root position (RRP) starting from class I to class V was 1%, 75%, 15%, 16%, and 3%, respectively.

Conclusion: A distinct correlation was found between the anterior root position and the available bone between the root tip and the nasal floor as per Gluckman's classification.

Clinical significance: This study helps in the radiographic evaluation of available bone around the roots of maxillary anterior teeth, which is a critical determining factor for treatment planning in IIP cases. A deep knowledge of RRP, bone morphology, and available alveolar bone beyond the apex provides useful perception to the clinician to plan surgical and grafting procedures to achieve primary stability. This will also help the clinicians to visualize the final prosthetic outcome with respect to the position of access hole.

Aim: To evaluate the effects of hydroxyapatite gypsum puger-cassava starch (HAGP-CS) scaffold on the number of osteoblasts and alkaline phosphatase (ALP) and osteocalcin (OCN) expression in the alveolar bone rat model.

Settings and design: In vivo study.

Materials and methods: Thirty-six Wistar rats were randomly divided into three groups: rat sockets were given a 1 mm × 1 mm × 1 mm HAGP scaffold, rat sockets were given a 1 mm × 1 mm × 1 mm HAGP-CS, and a control group (rat sockets were not given scaffold material). Following lower left molar extraction, scaffold materials were applied to the sockets. Assessments were conducted on days 7th, 14th, and 28th, with osteoblast counts determined via hematoxylin-eosin staining, and ALP and OCN expressions were analyzed using immunohistochemistry (IHC) staining.

Statistical analysis used: Two-way analysis of variance and Tukey's test.

Results: A significant increase in osteoblast count was observed on day 28 (P = 0.001). In addition, significant differences were noted in ALP expression on day 7 (P = 0.030) and day 28 (P = 0.001), as well as in OCN expression on days 7 and 28 (P = 0.001) across the groups.

Conclusions: Administering a HAGP-CS scaffold significantly enhances osteoblast proliferation and increases ALP and OCN expression in the alveolar bone rat model.

Aim: The aim of the study is to assess the antimicrobial efficacy at Implant-Abutment Interface (IAI) coated with metal ions (silver and gold) causing peri-implantitis, with the objective of comparing its antimicrobial properties.

Study setting and design: The study conducted is an in vitro experimental study.

Material and methods: A total of 90 specimens 45 Titanium alloy discs substitute for Implant (Ti-6Al-4V, Grade V) and 45 Stainless Steel (315L SS) disc substitute for Abutment were serially ground, polished and cleaned to be coated with gold (Au) and silver (Ag) ions by sputtering technique which was later tested for antimicrobial efficacy by means of agar disk diffusion method with gram negative microorganisms causing peri-implantitis, the measurement of inhibition zone (ZOI) encircling each sample were taken and noted.

Statistical analysis used: The mean zone of inhibition data for all the groups were subjected for statistical analysis by Tukey's multiple comparison test and one way ANOVA.

Results: The results showed that the antimicrobial efficacy of gold coated Titanium alloy-Stainless steel, (TiAu -SSAu) and Silver coated Titanium- stainless steel (TiAg-SSAg) were significantly higher with a mean ZOI value of 24.6mm (Prevotella intermedia) for gold coated and 17 mm for silver coated groups compared to Uncoated group Titanium alloy- stainless steel (Ti-SS) with a mean zone of inhibition of 10mm, also proved by Tukeys multiple comparison test with statistical significant difference in the antibacterial activity of gold coated group compared to other groups where p <0.0001 against Porphyromonas Gingivalis, Prevotella Intermedia and Aggregatibacter Actinomyces.

Conclusions: The surface modification of titanium alloy and stainless steel with metal ion coating (Au and Ag) significantly reduces the signs of peri-implantitis and thus leading to lasting success of implants.

Aim: The aim of this study was to evaluate the marginal gap of full-arch frameworks (FAFs) supported by all-on-four and all-on-six implant designs, fabricated using different manufacturing technologies.

Settings and design: This was an in vitro study.

Materials and methods: Fifteen titanium FAFs were fabricated using milling and three-dimensional printing techniques: selective laser melting (SLM) and electron beam melting (EBM) (n = 5/group). The marginal gap between the framework and abutment was measured using a microscope with 1 μm accuracy. Measurements were taken three times by a calibrated examiner (intraclass correlation coefficient of 0.996; P < 0.001) at the buccal and lingual interface between the abutment and the framework.

Statistical analysis used: A two-way ANOVA was applied to assess the effects of implant design and manufacturing technology (α = 0.05).

Results: When comparing implant designs, the all-on-four group (milling [P = 0.002] and SLM [P = 0.001]) exhibited lower marginal gap values than the all-on-six group. No statistically significant difference was observed between the EBM frameworks in both designs. In the all-on-four group, milling resulted in lower marginal gap values than SLM (P = 0.021) and EBM (P = 0.001), while no statistically significant difference was found between the SLM and EBM groups (P = 0.163). For the all-on-six framework design, the milling (P = 0.008) and EBM (P < .001) groups exhibited lower marginal gap values than the SLM group. No statistically significant difference was detected between the milling and EBM groups (P = 0.160).

Conclusion: Milled frameworks should be the preferred choice for rehabilitations using the all-on-four implant design. For the all-on-six design, both milled and EBM frameworks may be indicated. The marginal gap values observed for all FAFs designs and manufacturing technologies can be considered clinically acceptable.

Aim: The purpose of the study was to comparatively evaluate temporomandibular joint function and treatment response using joint vibration analysis (JVA) in patients exhibiting disc displacement with reduction (DDR), treated with three variable thickness of stabilization splints. JVA analyzed these vibrations to detect internal joint abnormalities, and their patterns were further categorized using the Piper classification was highly accurate and hence used over magnetic resonance imaging.

Settings and design: Randomized clinical trial.

Materials and methods: The splint of different thicknesses, i.e., Group A (3 mm), Group B (4 mm), and Group C (5 mm) were given to the study participants for 10 week interval, and pre and posttreatment efficacy was recorded using JVA. Stress perseverance and tooth wear index were recorded with a pre and postquestionnaire.

Statistical analysis used: The one way analysis of variance f test and Turkey's post hoc test for multiple comparisons were used to statistically assess the results.

Results: The treatment response with Group A and B thickness of stabilization splints was significant (P = 0.01) and with Group C was not significant (P = 5.28). The statistical result of stress perseverance was not significant between the three groups, although reflecting female participants were affected more. The tooth wear index was significant with all the three groups (P = 0.09).

Conclusion: The study concluded that the splints given to Group A and Group B showed effective treatment response, while Group C showed positive response in a few individuals, but some individuals compliant of discomfort. The stress level was high in female individuals. Among all the participants, the concern of tooth wear was present.

Aim: To evaluate and compare the surface roughness and impact strength of conventional polymethyl methacrylate (PMMA) with microcrystalline cellulose (MCC)-reinforced PMMA.

Settings and design: An in-vitro experimental study was conducted. Fifty PMMA specimens were fabricated and divided into five groups based on MCC concentration (2% or 5%) and particle size (20 μm or 50 μm).

Materials and methods: Specimens (80 mm × 10 mm × 4 mm) were categorized as follows: Group A (control; conventional PMMA), Groups B and D (2% MCC with 20 µm and 50 µm particles, respectively), and Groups C and E (5% MCC with 20 µm and 50 µm particles, respectively). Surface roughness was measured using a contact profilometer, and impact strength was tested with a ZwickRoell impact testing machine.

Statistical analysis used: Statistical analysis was performed using IBM SPSS Version 28.0. One-way ANOVA followed by Tukey's post hoc test was used to determine intergroup differences, with the significance level set at p<0.05.

Results: Surface roughness was lower in Groups B (0.89±0.43), C (1.07±0.34), and E (0.77±0.27) compared to the control Group A (1.25±0.42), while Group D (1.84±0.25) showed higher values. Impact strength in Groups C (1.85±0.23), D (1.80±0.17), and E (1.81±0.26) was slightly lower than the control (1.88±0.31), though not statistically significant. However, Group B (1.56 ± 0.20) showed a significant reduction.

Conclusion: The addition of 20 μm MCC reduced surface roughness at both 2% and 5% concentrations, whereas 50 μm MCC increased roughness at 2% but decreased at 5%. Impact strength remained comparable to the control in all groups except PMMA + 2% MCC (20 μm), which exhibited a significant decline. MCC reinforcement influences PMMA's mechanical and surface properties, suggesting its potential for denture base modifications.

Aim: Sustainability of dental polymethyl methacrylate (PMMA) in acidic environments is crucial as oral pH fluctuations can degrade the mechanical properties of denture bases. PMMA strengthening with polypropylene (PP) mesh has improved mechanical properties, but its effectiveness in acidic conditions remains underexplored. This investigation aimed to evaluate the mechanical properties of PP mesh reinforced PMMA (PP-PMMA) on exposure to an acidic environment as against unreinforced denture base resin (UN-PMMA).

Settings and design: Experimental In-vitro study.

Materials and methods: A total of 120 PMMA samples were prepared as per standardized guidelines and divided into two groups as unreinforced and PP - PMMA. Prepared specimens were immersed in artificial saliva and simulated gastric acid (0.06M HCl, pH 1.2) at 37°C for 96 hours to simulate long-term clinical exposure to an acidic environment. Flexural strength, impact strength, surface roughness and microscopic characteristics were assessed with aid of universal testing machine, Izod's impact tester, profilometer and high-resolution scanning electron microscope (HR-SEM) in order.

Statistical analysis used: The data were statistically analyzed using ANOVA and independent t-test set at a significance level of P-values less than 0.05.

Results: PP-PMMA exhibited significantly higher flexural strength in simulated gastric acid (70.03±1.4MPa) compared to UN-PMMA (68.77±2.2MPa) (P < 0.05). In simulated gastric acid (HCl), PP-PMMA showed no significant difference in surface roughness compared to UN-PMMA (P = 0.29). However, in artificial saliva, PP-PMMA exhibited lower surface roughness (0.47±0.14μm) than UN-PMMA (0.56±0.08μm) (P < 0.05), indicating improved smoothness. Impact strength remained comparable between groups in both immersion conditions (P > 0.05). The presence of mesh between the layers restricted the ingress of saliva and HCl as was perceived with rougher surface in the external area.

Conclusion: PP reinforcement improved the flexural strength of PMMA in acidic environments and maintained surface roughness in acidic environments but did not significantly enhance impact strength. Polypropylene mesh reinforcement effectively reduced porosities and maintained structural integrity within the PMMA matrix. These findings suggested that polypropylene mesh reinforcement enhances the durability of denture base materials and benefits patients with gastroesophageal reflux condition.

Aim: Microbial assessment of internal recess of two different internal implant connections in an in vivo study.

Study settings and design: This randomized, in vivo study included 40 patients requiring mandibular single-tooth implant-supported prostheses, allocated into two equal groups based on implant connection design.

Materials and methods: Group Internal Hex (IH) and group Conical Connection (CC) received implants with IH and CC, respectively. On the day of prosthetic loading, peri-implant sulcular fluid (PISF) sample was collected and stored. PISF samples were recollected after 3 months. Subsequently, the screw access hole was exposed, and the abutment screw was removed. Implant-abutment recess was washed with saline, lavage was sent for microbiological assay. The abutment screw and crown were restored. PISF was analyzed for interleukin-6 (IL-6).

Statistical analysis used: For nonparametric values Chi square test and for parametric values t-test was used to analyse the data.

Results: No implant failure or patient fallout was observed. In Group IH, 17 out of 20 samples were positive for aerobic viz-a-viz 7 samples from Group CC; P = 0.001. For anaerobic bacteria, similar results were obtained with a number of positive samples 19 as compared to 6 in respective groups; P = 0.00002. IL-6 values did not differ significantly from baseline to 3 months in either group.

Conclusion: Within the limitations of the study, results show higher bacterial contamination of implant recess in IH than CC. However, the bacterial load had an insignificant contribution to IL-6 levels in PISF of the patients of either group in this time period.

Aim: Maxillectomy patients frequently have speech impairments resulting from the loss of the oral-nasal partition. Prosthodontic rehabilitation with an obturator helps restore speech intelligibility, with its success largely dependent on accurate impression recording of maxillary defects. This investigation evaluated the effectiveness of conventional versus digital impression techniques in the context of speech analysis, specifically using Hindi vowels, in maxillectomy patients rehabilitated with obturators.

Study setting and design: This research, designed as a quasi-experimental study, was undertaken at a tertiary care hospital.

Material and methods: The study included 20 patients needing obturators, assigned to two groups: one received prostheses fabricated with conventional impressions, and the other with digital techniques. Speech parameters, including fundamental frequency, formant frequencies (F1, F2, F3), intensity, jitter, shimmer, and maximum phonation duration (MPD), were analyzed using Praat software before and three months after rehabilitation. Hindi vowels aa /a:/, ii /i:/, and uu /u:/ were sustained at a controlled intensity. Swallowing efficiency was assessed via the water swallow test.

Statistical analysis used: The Wilcoxon Rank Sum test or exact test was used to compare the data, with a p-value < 0.05 considered significant.

Results: The most common maxillectomy defects were Brown class 2b. After three months, significant improvement in speech parameters and swallowing efficiency was seen in both groups of participants. However, no statistically significant differences (P > 0.05) were found between the conventional and digital impression groups.

Conclusions: This novel study compared conventional and digital impressions for speech analysis using Hindi vowels in maxillectomy patients after rehabilitation with an obturator. Voice recording and acoustic analysis using Hindi vowels provide valuable insights into speech rehabilitation outcomes in maxillectomy patients. Both conventional and digital impression techniques effectively fabricate obturators, improving speech characteristics and intelligibility. Both methods can be used for maxillectomy patients, allowing flexibility in clinical practice.