The International journal of oral & maxillofacial implants最新文献

Background and aim: The Pink Esthetic Score (PES) is a widely used index for evaluating the esthetics of peri-implant soft tissue in the anterior region. With the advent of digital technology, clinicians increasingly rely on digital tools to capture data and evaluate PES using standardized methods. This study aimed to compare the outcomes of clinical and digital assessments of peri-implant soft tissue esthetics using PES.

Materials and methods: In this descriptive cross-sectional study, 24 patients with single implants in the anterior region were evaluated. The esthetic quality of the peri-implant soft tissue was assessed clinically and using scans obtained via an intraoral scanner, based on the PES. Scores were assigned for each parameter using a three-point scale: 0 (most differences), 1 (moderate differences), and 2 (least differences compared to the reference). Frequencies of PES scores were analyzed for each of the seven PES items, and total scores were calculated for both methods. Agreement between the two assessment methods was evaluated using weighted kappa statistics and the intraclass correlation coefficient (ICC).

Results: Out of 168 assessments, the clinical and digital modalities provided identical scores in 119 cases (70.8%). The weighted kappa for total scores was 0.64, indicating substantial agreement. Kappa values for individual parameters were as follows: 0.68 for mesial papilla, 0.69 for distal papilla, 0.54 for soft tissue margins, 0.66 for soft tissue contour, 0.68 for soft tissue color, 0.47 for soft tissue texture, and 0.62 for alveolar process deficiencies.

Conclusions: Substantial agreement was observed between clinical and digital assessments of peri-implant soft tissue esthetics in the anterior region. Intraoral scanners offer a reliable and advantageous method for evaluating PES, providing consistency and convenience for clinicians.

Purpose: The clinical condition known as single denture syndrome (SDS), or combination syndrome, or Kelly's Syndrome, is still not well understood and is not widely recognized in the literature or in dental practice. It occurs when a patient has a fully edentulous maxilla and a partially edentulous mandible; it commonly affects individuals who wear a complete maxillary denture, paired with a lower removable partial denture (RPD), which is supported by their remaining front teeth. Then, significant morphological and functional changes in the oral cavity can result from the progressive loss of teeth and the subsequent resorption of the maxillary and mandibular alveolar ridges associated with SDS. These changes ultimately affect the patient's overall oral health and quality of life. Thus, this study aimed to evaluate patient satisfaction after prosthodontic rehabilitation of cases with single denture syndrome.

Materials and methods: Two groups of patients were randomly assigned. Group I received a conventional lower removable partial denture and an upper conventional complete denture, and Group II received a lower removable partial overdenture supported and retained by two implants with locator attachments, along with an upper conventional complete denture. The study evaluated patient satisfaction with implant-assisted partial dentures using a 100-mm VAS at baseline and three months (measurable improvements in comfort, function, and overall satisfaction). Descriptive and inferential statistics, including ANOVA, paired t-tests, and Pearson correlations, were used to assess changes over time.

Results: Eighteen patients exhibiting signs of single denture syndrome (completely edentulous upper ridge and lower Kennedy Class I) were included in this study. Satisfaction scores showed that for 'speech', 'chewing', 'handling', and 'overall satisfaction', group I experienced a significant improvement after 3 months (p<0.05). In group II, there was a significant increase in value only in 'speech' and 'handling' parameters (p<0.05); in contrast, the changes in other parameters were not statistically significant (p>0.05).

Conclusions: Patients with SDS who wore lower implant-retained removable partial overdentures were more satisfied than those with lower conventional removable partial dentures.

Purpose: The objective of this study was to evaluate clinical outcomes among subjects with mandibular overdentures supported by a single parallel-walled or tapered dental implant placed according to the immediate loading protocol.

Materials and methods: Forty-seven edentulous subjects, (21 men and 26 women with a mean age of 61.5 years) with dentures fulfilled the criteria for inclusion and were scheduled for surgical implant placement. All subjects were provided with a single implant in the mandibular symphyseal area after which a Locator abutment was connected to the implant immediately following placement. The mandibular denture was modified and provided with the female attachment component and delivered the day of implant surgery. The subjects were scheduled for follow-up examinations 6 and 12 months after implant placement and yearly for another 4 years. Yearly examinations included a periapical radiograph to determine peri-implant bone level and clinical evaluation of denture stability, retention, wear, occlusion, and mucosal health.

Results: Forty of the 47 subjects, (19 men and 21 women with a mean age of 64.1 years) were available for the 12-month follow-up. The parallel-walled implant group (Group 1) included 20 subjects (8 men and 12 women) and the tapered implant group (Group 2) included 20 subjects (11 men and 9 women). Seven subjects were excluded during the first year; two subjects could not be reached and were lost to follow-up, one had died, three subjects had failing implants and one subject requested to have the implant removed. The mean peri-implant bone change was 0.29 mm (range 0 to 1.8 mm) and the Implant Stability Quotient (ISQ) remained stable with no significant differences between the groups. The most common need for maintenance was replacement of the retentive nylon insert.

Conclusions: No significant differences were found between subjects in the two groups with respect to implant survival rates and peri-implant bone loss. Need for denture maintenance was mostly related to replacement of retentive nylon caps.

Purpose: The aim of this study is to compare the effects of different occlusal forces on quad zygoma, transnasal and pterygoid implants in patients with severely atrophic maxilla using finite element analysis.

Materials and methods: Using cone beam computed tomography data from a patient with a severely atrophic maxilla, a three-dimensional finite element analysis model was created. Three models were developed: Model 1, a quad zygoma model with four zygomatic implants placed using the extrasinus technique; Model 2, a combination of one zygomatic implant placed using the extrasinus technique and one transnasal implant; and Model 3, with transnasal, zygomatic and pterygoid implants. Two different forces were applied: a 150 N vertical force at the first, second premolar and the first molar region and functional force consisting of a 100 N vertical force combined with a 50 N horizontal force at the same locations. Stress values in the bone, implants, abutments and prosthetic framework were evaluated.

Results: The quad zygoma model (Model 1) demonstrated the highest stress values on the implant, abutment, and prosthetic framework under both vertical and functional forces. Model 2, which included transnasal and zygomatic implants, showed lower stress values compared to Model 1. Model 3, supported by pterygoid implants, exhibited lower stress levels on the bone, implants, abutments and prostheses compared to the other models.

Conclusions: According to the results of our study, the use of transnasal implants with zygomatic implants presents a method as an alternative to quad zygoma protocol. Additionally, in the model supported by pterygoid implants, the absence of cantilevers resulted in reduced stresses on the bone, implant, abutment, and prosthetic framework. We recommend the application of pterygoid implants alongside zygomatic and transnasal implants for long-term success and the prevention of biomechanical complications in the rehabilitation of severely atrophic maxilla.

Purpose: Implant overdenture rehabilitation has recently become a common treatment for patients. However, few papers present long-term observations (over 10 years) of IOD/IRPD. The purpose of this study was to investigate the clinical results of 'planned' IOD/IRPD provided at Tsurumi University Dental Hospital over approximately 20 years, as a retrospective cohort study.

Materials and methods: To investigate the clinical results of 'planned' IOD/IRPD, a survey was performed regarding patients who had received IOD/IRPD at our University Dental Hospital and underwent regular maintenance between August 2000 and August 2020. The data of 'rescue' overdentures, which have poor survival rates, were excluded in this study. Descriptive statistics show the age and gender ratio of the target patients, the length and diameter of the placed implants, implant position and number, denture designs, types of attachment, marginal bone loss (MBL) around implants, implant survival rate, prosthetic complications, and patient satisfaction. Kaplan-Meier curves were computed for IOD/IRPD survival analysis with implant failure as the endpoint, and log-rank tests were used to assess the IOD/IRPD rehabilitation.

Results: The selected patients were 78 (32 males and 46 females). Eighty-six IODs/IRPDs were manufactured-Maxillary: 31 (IODs: 23, IRPDs: 23); and mandibular: 55 (IODs: 35, IRPD: 20). Regarding the survival rate of IOD/IRPDs, measured by the endpoint of implant failure, the survival rate of mandibular implants was significantly higher than that of maxillary implants (p<0.05). However, there was no significant difference between mandibular IOD and IRPD (p>0.05).

Conclusions: All 'planned' IODs/IRPDs were confirmed to maintain successful conditions for 5 years after the commencement of function. Many implant failures were observed in maxillary IODs/IRPDs with mandibular antagonist teeth. Even when biological and prosthetic complications occurred in IODs/IRPDs more than 5 years after function, higher.

Purpose: Morse taper connection presents better functional load distribution than other types of connections. The angle and finishing surfaces are used to prevent components from loosening under direct axial load. The angulation of the connection walls for the Morse effect to exist should be from 6° to 16°. Therefore, there is a lack of consensus regarding the most appropriate conical connection from both biological and mechanical perspectives. This study aimed to evaluate the influence of different conicities (10°, 16°, 22°, and 24°) of implants with conical connections on the adhesive wear of the prosthetic abutment after the application of the tightening torque.

Materials and methods: Twenty implant sets, abutment with different conicities (10, 16, 22, and 24 degrees) were analyzed using five implants and five abutments, divided into four groups according to the taper angle: A-10° (Emfils, São Paulo Brazil); A-16° (SIN, Sao Paulo, Brazil); A-22° (Nobel Biocare, Zurich, Switzerland); and A-24° (Conexão Sistema de Prósteses, São Paulo, Brazil). The 20 implants were installed in specimens with a stability of 60N·cm, and their respective abutments were subjected to an installation torque of 32N·cm. After being subjected to the recommended torque, the abutments were subjected to detorque for scanning electron microscopy (SEM) analysis. The images obtained of the prosthetic abutments were delineated.

Results: The adhesive wear areas outlined in the ImageJ and values of detorque were analyzed. After statistical analysis of the data, it was observed that group A-24° presented a higher detorque value compared to the other groups (p<0.05). In contrast, the others did not show significant differences among them (p>0.05). For the adhesive wear score, it was observed that group A-16° presented the highest adhesive wear scores, with a statistically significant difference compared to group A-10° (p<0.05). For the other conicities, no difference was observed (p>0.05).

Conclusion: It is possible to conclude that the conicity of 16° presented a higher adhesive wear score after tightening the torque of the prosthetic abutment.

Purpose: To compare clinical outcomes of short (6 and 8 mm) and standard-length (11 and 13 mm) implants in posterior sites. It was hypothesized that both implant types exhibit no difference regarding implant survival rate and marginal bone level change (MBLC).

Materials and methods: In this prospective observational study, implant survival and success rates, soft tissue conditions, and MBLC were observed over a period up to 36 months. Short and standard-length OsseoSpeed® Astra Tech implants were used to replace at least two up to three missing teeth. Data regarding the patients' medical history, clinical and radiographic parameters were analysed.

Results: Thirty-eight patients (42 standard-length and 64 short implants) were available for follow-up. Neither implant loss nor mobility were recorded throughout the observation period. Considering MBLC ≥ 2 mm, no significant difference of success rate of short (76.9 %) and standard-length (76.2 %) implants was noted. Considering MBLC, success rates of short (88.7 %) and standard-length (100 %) implants differed significantly (Log-rank test, p = 0.028). Compromised medical history, implant site (maxila or mandible), bone quality, type of prosthetic restoration (single non-splinted or splinted crowns or fixed partial dentures), keratinized mucosa width ≥ 2 mm were not associated with MBLC. Premature cover screw exposure and MBLC ≥2 mm were significantly associated within the group of short implants (p = 0.045), but not in standard-length implants (p = 0.853). Short implants in smokers were under higher risk to MBLC exceeding 3/10 of implant length compared to non-smokers (p = 0.022).

Conclusions: Short and standard-length implants revealed a comparable survival and success rate regarding MBLC ≥2 mm but differed significantly considering MBLC > 3/10 of enossal implant length. Short implants are more prone to MBLC compared to standard-length implants, especially in smokers, or when premature cover screw exposures occur.

Background: Implant-supported single crowns (ISSCs) are a common treatment option for replacing missing teeth in the anterior maxilla. Extensive long-term studies are still needed to report on esthetic qualities, clinical performance, potential complications, and overall patient satisfaction with this treatment.

Purpose: This study aims to elucidate the long-term esthetic qualities, clinical outcomes, and patient satisfaction with ISSCs in the anterior maxilla.

Materials and methods: Of 172 patients provided with ISSC, 107 patients with 133 single crowns accepted participation in a follow-up study after 11-21 years. Esthetics were assessed using the Pink Esthetic Score (PES), the White Esthetic Score (WES), and the California Dental Association index (CDA). Patients completed questionnaires on esthetics, function, complications and health. Most patients were enrolled in planned follow-up visits according to the clinic's routine. Photographs and radiographs at follow-up were compared with photos and radiographs taken at the placement of the crown. Data were analyzed using descriptive statistics, chi-square test, Fischer exact test, multiple regression, and Cohen's Kappa for inter-rater reliability.

Results: Infraposition was observed in 68% of ISSCs, but only 8% had an infraposition of ≥ 1 mm. Significant differences between sexes were found in the groups without (p < 0.001) or slight infraposition (0.1-0.5 mm) (p = 0.001), with men showing less infraposition. Patients with an infraposition of ≥ 0.5 mm were more likely to notice this difference (p = 0.032). Esthetic assessments gave lower scores for color compared to shape, and color mismatch increased over time. Despite these issues, patient satisfaction remained high, with most patients unaware of positional or color differences of their ISSCs. The survival rate was 99% for implants and 92% for crowns. Bone loss was limited, with 86% of the implants having less than 1.2 mm bone loss up to 10 years, and only 7% had a bone loss exceeding 1.8 mm.

Conclusions: A high percentage of ISSCs placed in the anterior maxilla exhibited infraposition and an increasing color mismatch over time. Implant and crown survival was high, with few complications and a limited mean bone loss. Patient satisfaction was high despite color mismatch and infraposition.

Purpose: To evaluate the effect of screw access hole (SAH) presence and location on the marginal and intaglio fit and fracture resistance of zirconia crowns.

Material and methods: Implants were placed in a maxillary first molar dentiform at 0, 15 and 30 degrees- angulations. Based on implant angulation, custom titanium abutments and zirconia crowns were fabricated. Crowns were divided into 4 groups: 0/NSAH (no SAH), 0/SAH (SAH at 0 degrees), 15/SAH (SAH at 15 degrees) and 30/SAH (SAH at 30 degrees), with 13 specimens er group. Marginal and intaglio gaps were measured using the silicone replica technique. Crowns were cemented with resin cement after sandblasting. All specimens underwent thermocycling and dynamic loading. Fracture load was measured using a universal testing machine. Fracture surfaces were analyzed with SEM and fracture patterns were classified.

Results: The 0/NSAH group exhibited significantly greater marginal and intaglio gaps and higher fracture load than the SAH groups (P <.05). No significant differences were observed among the SAH groups. The occlusal area gap was the largest across all groups. SAH location affected fracture patterns: fractures in the 0/SAH and 15/SAH groups commonly involved the SAH, while those in the 30/SAH group did not.

Conclusions: The presence of an SAH improved fit but reduced fracture resistance. SAH location did not influence fit or strength but affected fracture pattern depending on proximity to the loading point.

The volume and morphology of alveolar bone drives the rehabilitation of edentulous patients. Rehabilitation of the atrophic ridge remains a challenge, both surgically and prosthetically. Commonly, bone grafting procedures, in combination with endosseous dental implants, are necessary. Graftless options, using tilted and/or longer endosseous dental implants placed into pyriform rim, nasal, pterygoid, and zygomatic bone have been developed to treat these problem cases. These options are technique sensitive and can result in increased patient morbidity. Digitally planned, custom milled, and rigidly fixated subperiosteal implants offer removable or immediate fixed options when conventional treatments are contraindicated or fail. Although this new treatment has recently been Food and Drug Administration (FDA) approved, it has been used successfully in Europe for over 10 years with overdenture final prostheses. This case series reports on the treatment of seven severely atrophic maxillae treated with a digitally planned and milled, rigidly fixated subperiosteal implant, restored with a full-arch immediate-load protocol with fixed provisional and definitive (final) restorations.