Journal of prosthodontic research最新文献

Purpose: This network meta-analysis (NMA) of randomized controlled trials (RCTs) aimed to identify effective initial conservative treatment strategies for patients with temporomandibular joint disorders (TMD).

Study selection: RCTs comparing treatment options for TMD published between January 2000 and July 2021 were retrieved from the databases of PubMed and Embase via a comprehensive electronic search. Patients diagnosed with myalgia (muscle pain) or arthralgia (joint pain) according to pain-related Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were eligible for inclusion. Twelve treatment options and a placebo were included in the mutual comparisons. The risk of bias was assessed using Risk of Bias 2.0. Forest plots of direct comparisons between individual studies were created using MetaInsight. NMA was performed using R statistical software (netmeta).

Results: Twenty-four RCTs involving 1336 patients assessing pain and 12 RCTs involving 614 patients assessing maximal mouth opening were identified. Low-level laser therapy (standard mean difference [SMD]: -2.12, 95% confidence interval [CI]: -3.18, -1.06), self-exercise (SMD: -1.51, 95% CI: -2.82, -0.2), and stabilization splints (SMD: -1.16, 95% CI: -2.02, -0.29) were effective in improving pain; however, the certainty of evidence was very low. Self-exercise (SMD: 0.71, 95% CI: -0.58, 2.01), stabilization splints (SMD: 0.65, 95% CI: -0.09, 1.39), and low-level laser therapy (SMD: 0.63, 95% CI: -0.34, 1.6) were effective in improving maximal mouth opening; however, the certainty of evidence was very low.

Conclusions: Stabilization splints, self-exercise, and low-level laser therapy may be effective in the initial treatment of TMD.

Purpose: Additive cast-fabrication has yet to be used as commonly in implant prosthodontics as conventional methods. This review aimed to investigate the accuracy of additive cast-fabrication in implant prosthodontics.

Study selection: The study protocol was registered in the PROSPERO database (CRD42022374972). Reporting was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, following the Cochrane Handbook. Two-arm interventional studies that matched the PICO were included (Population: dental typodonts with implants, Intervention: additive cast-fabrication, Comparator: conventional cast-fabrication, Outcome: positional deviations). A systematic search was conducted in three databases: PubMed (MEDLINE), EMBASE, and the Cochrane Library (CENTRAL).

Results: Seven papers were included in the analysis of horizontal, vertical, and root mean square (RMS) deviations. No significant differences were observed between groups. The overall vertical mean deviation of the intervention group was -4.15 µm [-24.88; 16.57], and the pooled mean absolute deviation was 22.43 µm [8.33; 36.54]. In the control group, these values were 19.67 µm [-32.71; 72.04] and 24.62 µm [0.00; 59.42], respectively. The overall horizontal mean deviation in the intervention group was 21.29 µm [-77.10; 119.68], and the pooled mean absolute deviation was 26.96 µm [0.00; 70.81]. In the control group, the overall mean was 1.45 µm [-32.26; 35.15] and the pooled mean absolute deviation was 25.05 µm [9.08; 41.01]. The mean RMS was only slightly larger in the intervention group, with the value of 14.74 µm [-107.26; 136.74].

Conclusions: Additive cast-fabrication is as accurate as the conventional method for the position of implant analogs.

Purpose: This study aimed to compare the deviation of hypermobile teeth in partially edentulous dental arches during impression taking using digital and conventional techniques.

Methods: A partially edentulous mandibular model with three target hypermobile teeth (including the left first premolar, #34; left second molar, #37; and right first premolar, #44), was used as the simulation model. After reference data were acquired using a desktop scanner, impressions of the simulation model were obtained using a digital intraoral scanner (IOS) and two conventional techniques (hydrocolloid material with a stock tray and silicone material with a custom tray as impression data (n=12/group). The three-dimensional accuracy (root mean square value) and two-dimensional accuracy (mesiodistal and buccolingual displacements) of the target teeth in each impression dataset were calculated based on the reference data. The comparison among three impression techniques was statistically performed using the Kruskal-Wallis test (α=0.05).

Results: For #34 and #44, the three- and two-dimensional accuracies of the impressions fabricated through data acquired through digital scanning (digital impression) were significantly superior to those of the hydrocolloid impression (P < 0.05), whereas no significant difference was found between the digital and silicone impressions. For #37, no significant difference in the accuracy of the impression data for the target teeth was observed among the three impression techniques.

Conclusions: Digital impression acquiring using an IOS is recommended over using a conventional hydrocolloid impression to prevent the deviation of hypermobile teeth in partially edentulous dental arches. Hypermobile tooth deviation in digital impression data depends on the tooth location.

Purpose: The innate immune response, particularly the reaction of polymorphonuclear neutrophils (PMNs), is crucial in shaping the outcomes of chronic inflammation, fibrosis, or osseointegration following biomaterial implantation. Peri-implantitis or peri-mucositis, inflammatory conditions linked to dental implants, pose a significant threat to implant success. We developed a single-cell analysis approach using a murine model to assess the immune response to implant materials, offering a practical screening tool for potential dental implants.

Methods: We performed bioinformatics analysis and established a peri-implant inflammation model by inserting two titanium implants into the maxillary region, to examine the immune response.

Results: Bioinformatics analysis revealed that titanium implants triggered a host immune response, primarily mediated by PMNs. In the in vivo experiments, we observed a rapid PMN-mediated response, with increased infiltration around the implants and on the implant surface by day 3. Remarkably, PMN attachment to the implants persisted for 7 days, resembling the immune profiles seen in human implant-mediated inflammation.

Conclusions: Our findings indicate that persistent attachment of the short-living PMNs to titanium implants can serve as an indicator or traits of peri-implant inflammation. Therefore, analyzing gingival tissue at the single-cell level could be a useful tool for evaluating the biocompatibility of candidate dental implants.

Purpose: To compare the effectiveness of keratinized mucosa (KM) augmentation with different techniques for the treatment of dental implants based on risk assessment.

Methods: Thirty-nine patients who underwent KM augmentation at implant sites in the posterior mandible were included. Three techniques were used based on anatomy-guided risk assessment: an apically positioned flap (APF) alone, an APF plus a free gingival graft (APF plus FGG), and an APF plus a collagen matrix (APF plus CM). Clinically effective KM augmentation was defined as remaining KM ≥ 2 mm after the intervention. The effective rate, implant/prosthesis survival rates, and bone/soft tissue parameters were analyzed. The correlation between local anatomical characteristics and different techniques was also determined. The associations between the effectiveness of KM augmentation and related factors were analyzed using a linear model.

Results: Overall, 74 sites received KM augmentation in the posterior mandible, for an effective rate of 94.6% at the 1-year follow-up and 93.2% at the 5-year follow-up. The KM width in the APF plus FGG group (3.85 ± 1.22 mm) was greater than that in the APF alone (3.05 ± 0.90 mm) (P = 0.016) and APF plus CM (3.21 ± 1.17 mm) groups (P = 0.038) at 5 years post-surgery. There was no significant difference in the effective/ineffective outcomes at the 1-year or 5-year follow-up among the three groups.

Conclusions: Comparable effective outcomes were achieved with three KM augmentation techniques following the decision-making criterion based on risk assessment.

Purpose: The lack of occlusal support reportedly reduces cognitive function; however, the underlying mechanisms remain unclear. The locus coeruleus, which is located adjacent to the trigeminal mesencephalic nucleus, secretes noradrenaline throughout the brain. In this study, we evaluated the effects of noradrenaline in the hippocampus and cerebral cortex on cognitive decline following tooth extraction in rats.

Methods: We performed passive avoidance experiments on male Wistar rats with extracted maxillary molars and determined the neuron density in the locus coeruleus and trigeminal mesencephalic nucleus using immunostaining and Nissl staining, respectively. We also assessed noradrenaline concentrations in the hippocampus and cerebral cortex using enzyme-linked immunosorbent assay.

Results: In the passive avoidance experiment, the latency in the bright compartment was significantly shorter (P < 0.05) in the extraction group than in the control group. The numbers of cells in the locus coeruleus and trigeminal nucleus were significantly lower (P < 0.05) in the extraction group compared to those in the control group. The noradrenaline levels in the hippocampus and cerebral cortex were also significantly lower (P < 0.05) in the extraction group than those in the control group.

Conclusions: The lack of occlusal support associated with tooth extraction reduces the number of cells in the trigeminal mesencephalic nucleus and locus coeruleus, which may reduce the supply of noradrenaline to the cerebral cortex and hippocampus, leading to a decline in cognitive function.

Purpose: This in vitro study investigated the effect of build orientation on the wear resistance and hardness of denture teeth fabricated using digital light processing (DLP) compared to other denture tooth materials.

Methods: Disc-shaped specimens were prepared using denture tooth monomers and DLP devices in three build orientations: 0°, 45°, and 90°. Specimens of the same shape were fabricated using denture tooth materials for subtractive manufacturing, commercially available polymethylmethacrylate (PMMA) resin, and composite resin. The wear resistance was evaluated as the wear volume loss after 50,000 wear cycles using a ball-on-disc wear device in water for two-body wear and poppy seed slurry for three-body wear. The Vickers hardness values of the materials were measured. Two-way and one-way analyses of variance were performed for wear resistance and hardness, respectively, followed by Tukey's honest significance test.

Results: The interaction between the denture tooth resins and maximum wear volume was significant (P < 0.01). The 0° build orientation exhibited the lowest wear volume in the three-body wear test and the highest hardness among the three build orientations. The 0° DLP-fabricated specimens demonstrated significantly less wear volume than that of the PMMA specimens and a wear volume comparable to that of the milled specimens. However, the 0° DLP-fabricated specimens showed significantly lower hardness than that of the milled and PMMA specimens. The composite resin specimens exhibited the highest wear resistance and hardness.

Conclusions: A 0° build orientation is recommended for DLP-fabricated denture teeth compared to 45° and 90° orientations to achieve greater wear resistance and hardness.

Purpose: Poor contour of the implant restoration causes plaque accumulation and increases the risk of peri-implantitis. This study aimed to investigate whether the prosthodontic components of dental implants were associated with the prevalence of peri-implantitis.

Methods: We enrolled 185 patients with 348 implants who underwent at least 1-year follow-up after the delivery of the prosthesis from February 2010 to January 2021. Demographic data of the patients and implants and the follow-up period were recorded. The emergence angle, type of cervical crown contour, and contour angle were analyzed using annual bite-wing radiographs. Peri-implantitis in this study was diagnosed if the peri-implant bone loss was greater than 2 mm between the bite-wing radiographs taken at baseline and the latest. Chi-square test, two-sample t-test, and multivariate logistic regression were used to investigate the differences and odds ratios between the peri-implantitis and non-peri-implantitis groups.

Results: The incidence of peri-implantitis was 14.9% during a follow-up period of 1509 days after the delivery of the prosthesis for at least 1-year. Based on the prevalence of non-peri-implantitis and after adjusting for confounding factors, the risk factors identified were bone types for implants (native bone vs. alveolar ridge preservation: adjusted odds ratio = 2.43, P = 0.04). Sex, arch, and guided bone regeneration vs. alveolar ridge preservation have the potential for a statistical difference.

Conclusions: Compared with implants at alveolar ridge preservation sites, implants in the native bone were more prone to peri-implantitis. Further randomized controlled trials are required to determine these associations.

Purpose: The maintenance of peri-implant health relies significantly on the integrity of the peri-implant seal, particularly vulnerable at the interface between implant abutment and soft tissue. Early healing stages around implants involve cellular exposure to oxidative stress. This study aimed to investigate whether vacuum ultraviolet (VUV)-treated titanium augments the growth and functionality of human gingival fibroblasts while mitigating cellular stress.

Methods: Machined titanium plates underwent treatment with 172 nm VUV light for one minute, with untreated plates as controls. Human gingival fibroblasts were cultured on treated and untreated plates, and their behavior, growth, and functionality were assessed. Functionally impaired fibroblasts, treated with hydrogen peroxide, were also cultured on these titanium plates, and plate-to-plate transmigration ability was evaluated.

Results: Fibroblasts on VUV-treated titanium exhibited a 50% reduction in intracellular reactive oxygen species production compared to controls. Additionally, glutathione, an antioxidant, remained undepleted in cells on VUV-treated titanium. Furthermore, the expression levels of inflammatory cytokines IL-1β and IL-8 decreased by 40-60% on VUV-treated titanium. Consequently, fibroblast attachment and proliferation doubled on VUV-treated titanium compared to those in the controls, leading to enhanced cell retention. Plate-to-plate transmigration assays demonstrated that fibroblasts migrated twice as far on VUV-treated surfaces compared to those in the controls. In particular, the transmigration ability, impaired in functionally impaired fibroblasts on the controls, was preserved on VUV-treated titanium.

Conclusions: VUV-treated titanium promotes the growth, function, and migration of human gingival fibroblasts by reducing cellular stress and enhancing antioxidative capacity. Notably, the transmigration ability significantly improved on VUV-treated titanium.

Patient: A 67-year-old woman presented to our clinic with chief complaints of headache and mandibular heaviness. Physical examination revealed bilateral tenderness in the temporalis and masseter muscles, corresponding to the patient's chief complaint. Thus, a diagnosis of temporomandibular disorders (TMDs)-related headache was made. However, sleep disorders were identified after further consultation. Hence, sleep apnea-related headache was suspected due to a snoring habit with a Mallampati classification of Class IV. Out-of-center sleep testing (OCST) revealed a respiratory event index (REI) of 10.1/h and a low peripheral oxygen saturation (SpO₂) of 76%. Consequently, a diagnosis of obstructive sleep apnea (OSA) was made, and treatment using the mandibular advancement device (MAD) was recommended. Following MAD treatment, the patient's sleep quality improved, and morning headaches ceased. Subsequent OCST performed while wearing the MAD showed a significant reduction in the REI to 1.6/h and an increase in the SpO₂ to 86%, indicating the therapeutic efficacy of the MAD in treating OSA.

Discussion: MAD treatment effectively alleviated the patient's morning headaches, suggesting that sleep bruxism should not be considered the only cause of headaches. OSA should also be considered and addressed when investigating the potential causes of morning headaches in patients.

Conclusions: In patients experiencing TMDs symptoms and morning headaches, TMDs should not be presumed as the sole cause. Dentists should discuss the likelihood of sleep disorders during consultations. If sleep disorders are suspected, the possibility of OSA should be considered, and sleep tests should be conducted when necessary.