Single‐piece zirconia versus single‐piece titanium, narrow‐diameter dental implants in the anterior maxilla: 5‐year post‐loading results of a randomized clinical trial

Clin Oral Impl Res. 2024;00:1–14. | 1wileyonlinelibrary.com/journal/clr Received: 1 December 2023 | Revised: 20 May 2024 | Accepted: 2 June 2024 DOI: 10.1111/clr.14319 ORIGINAL ARTICLE Singlepiece zirconia versus singlepiece titanium, narrowdiameter dental implants in the anterior maxilla: 5year postloading results of a randomized clinical trial Paula Andrea Ruiz Henao1 | Gabriel Leonardo Magrin1,2 | Leticia CaneiroQueija1 | Cesar Augusto Magalhães Benfatti2 | Yago Leira1 | Antonio LiñaresGonzález1 | Juan BlancoCarrión1 This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2024 The Author(s). Clinical Oral Implants Research published by John Wiley & Sons Ltd. Clinical Trial Registration: This clinical trial has been registered in clinical trials with the identifier CI_RCT_US16 and registration number NCT04707677. 1Unit of Periodontology, Department of Surgery and MedicalSurgical Specialties, Faculty of Medicine and Dentistry, University of Santiago de Compostela, Santiago de Compostela, Spain 2Center for Education and Research on Dental Implants (CEPID), Department of Dentistry, Federal University of Santa Catarina (UFSC), Florianópolis, Brazil Correspondence Yago Leira Feijoo, Unit of Periodontology, Departament of Surgery and MedicalSurgical Specialities, Faculty of Medicine and Dentistry, University of Santiago de Compostela, Santiago de Compostela, Spain. Email: [email protected] Paula Andrea Ruiz Henao, Unit of Periodontology, Department of Surgery and MedicalSurgical Specialties, Faculty of Medicine and Dentistry, University of Santiago de Compostela, Santiago de Compostela, Spain. Email: [email protected] Gabriel Leonardo Magrin, Center for Education and Research on Dental Implants (CEPID), Department of Dentistry, Federal University of Santa Catarina (UFSC), Campus Reitor João David Ferreira Lima s/n, 88040900, Florianópolis, SC, Brazil. Email: [email protected] Funding information Institut Straumann AG; Institute of Health Carlos III, Grant/Award Number: CD22/00051 Abstract Objectives: The aim of this study was to evaluate esthetic parameters in the anterior maxillary region by comparing singlepiece zirconia versus titanium narrowdiameter implants. Additionally, clinical, radiological and patientreported outcome measures (PROMs) were analyzed. Materials and Methods: Thirty implants (tissue level implant) were placed in 30 patients in the maxillary esthetic sector. Depending on randomization, a zirconia (test) or titanium implant (control) was placed. Esthetic, clinical, and radiological parameters, including the implant crown esthetic index (ICAI), pink esthetic score (PES), probing pocket depth, bleeding on probing, plaque index, and marginal bone levels, were evaluated at 12, 36 and 60 months after loading. Results: Sixty months after crown placement, no significant differences were found between groups. The ICAI values were 5.25 ± 4.21 and 4.50 ± 2.98 for the test and control groups, respectively. The corresponding PES values were 7.44 ± 1.93 and 7.43 ± 1.74 for the test and control groups, respectively. There were no significant intergroup differences for the rest of the parameters evaluated. Conclusion: It can be suggested that monotype zirconia implants may serve as a potential alternative to titanium implants in selected clinical scenarios. While the results demonstrated comparable esthetic, clinical, and radiological aspects for zirconia implants as compared to titanium implants after a 5year followup period, further research with larger sample sizes and longerterm followup is recommended. KEYWORDS dental implants, esthetics, longitudinal studies, randomized controlled trial, singletooth dental implants, zirconia dental implants 2 | RUIZ HENAO et al. 1 | INTRODUCTION Many different types of titanium have been used over the past decades as the materials of choice for dental implants. However, titanium implants may negatively impact esthetics if surgical planning or implant positioning is not correct (SanzMartín et al., 2020). Preclinical and clinical studies have shown that a grayish color can be visible through periimplant soft tissues in patients with thin oral mucosa thickness (Pitta et al., 2020; Thoma et al., 2016). Although it has not been demonstrated given the difficulty and scarcity of clinical data, it has been reported that titanium particles released from implants as products of chemical and physical corrosion can induce hypersensitivity reactions and possibly allergies in susceptible patients (Asmarz et al., 2021; Dhein et al., 2022; Poli et al., 2021; Sicilia et al., 2008; Siddiqi et al., 2011). To overcome these limitations, zirconia implants were introduced when a risk of discoloration of periimplant soft tissues is high (Sales et al., 2023). Nevertheless, there is few data on the use of zirconia implants in patients, and comparisons between titanium and zirconia implants are even scarcer. Numerous preclinical studies provided a robust evidence on the biocompatibility of ceramic materials (Gahlert et al., 2009, 2012; Kohal et al., 2004; Rocchietta et al., 2009). In vitro experiments have also shown that zirconia is capable of withstanding longterm loads (Andreiotelli et al., 2009; Cionca et al., 2017) and a 100% success rate was observed in a retrospective case series after 10 years of followup, which is essential for its possible clinical application (Borgonovo et al., 2021). However, current clinical evidence on this topic is limited by the small sample size of studies and short longitudinal evaluation. In relation to a longer followup period, there are few randomized clinical trials with followup greater than 1 year (Koller et al., 2020; Lv et al., 2023; Osman et al., 2014; Payer et al., 2015; Ruiz Henao et al., 2021). The white color of zirconia implants, composed of zirconium dioxide (ZrO2), can mimic that of natural teeth, thereby enhancing esthetic outcomes (Lv et al., 2023). Moreover, zirconia implants have a low affinity for plaque, reducing the risk of inflammation in the adjacent soft tissues (Cionca et al., 2017; Liñares et al., 2016). Histological investigations have hardly observed inflammatory cells in the periimplant mucosa of zirconia components (Kohal et al., 2004). In addition, there has been an increasing demand for metalfree rehabilitations due to personal or allergic reasons (Liñares et al., 2016; Poli et al., 2021). Recently, our group published a randomized clinical trial comparing the esthetic, radiological, and clinical outcomes of onepiece zirconia implants with titanium implants of identical macrogeometric design in the anterior maxilla, and no significant differences were observed at 12 months postloading (Ruiz Henao et al., 2021). The aim of present study was, therefore, to prospectively evaluate the same zirconia and titanium implants placed in the anterior maxilla, comparing the esthetic outcomes in a 5year postloading followup. The primary outcome of this study was the Implant Crown esthetic Index (ICAI). Additionally, clinical and radiological parameters, as well as the occurrence of complications and patientreported outcome measures (PROMs), were assessed. 2 | MATERIALS AND METHODS 2.1 | Study design and ethical aspects The present study was designed as a singleblinded (patient), prospective, randomized, controlled, parallel arm clinical trial, comparing zirconia singlepiece (test group) versus titanium (control group) implants, for singletooth replacement in the anterior maxilla. The operator did not know the group to which each patient belonged until the time of surgery. After lifting the flap, a sealed envelope was opened to the surgeon with the type of implant corresponding to the patient. To determine the sample size, results of a clinical study that compared titanium and zirconia abutments were used (Carrillo de Albornoz et al., 2014). A sample size calculation was conducted using changes in the ICAI, resulting in a standard deviation of approximately 1.76. With an effect size of 3 and a power of 95% (alpha = 5%, beta = 80%), a sample size of 18 patients was estimated. However, to ensure the normal assumption, as recommended by the SPSS program, the sample size was increased to 30 patients. The research was performed at the Unit of Periodontology of the University of Santiago de Compostela, Spain, and the 5year data collection was approved by the ethical committee of Galicia (423/2015). The study was carried out in compliance with the Helsinki Declaration and following the CONSORT guidelines (Schulz et al., 2010). This clinical trial was registered in clinical trials database (registration number: NCT04707677). 2.2 | Study population and intervention To be eligible for participation, patients had to meet the following inclusion criteria: they had to be periodontally and systemically healthy individuals over 18 years old, with good plaque control (less than 25% plaque coverage). Additionally, patients should have been missing a tooth in the anterior maxilla (from tooth 13 to 23, inclusive) with natural teeth adjacent on both sides (creating a single gap), and they should have had a minimum of 4 months of healing following tooth extraction before implant insertion. Furthermore, participants needed to have at least 2 mm of keratinized tissue present. Simultaneous bone regeneration was permitted during surgery. Exclusion criteria included the use of any medications or the presence of systemic diseases affecting bone metabolism, pregnancy or lactation, active periodontal disease, or smoking 10 or more cigarettes per day. They were recruited 30 patients (16 female, 14 male; mean age = 55.1 years) with singletooth edentulism in the anterior maxilla (canine to canine) from January 2016 to March 2017. The 5year monitoring period ended in April 2023. All patients were provided with both oral and written information regarding the study and were required to sign an informed consent form to participate. Details of the 1year data were reported in a previous publication (Ruiz Henao et al., 2021). Patients were randomized and allocated to each study 16000501, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/clr.14319 by Consorcio Interuniversitario Do Sistema Universitario De Galicia (Cisug), Wiley Online Library on [10/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License | 3 RUIZ HENAO et al. group using a computergenerated randomization list. Assignment was determined by opening sealed opaque envelopes containing a code derived from the random list. These envelopes were opened after flap elevation but before osteotomy. According to a randomization, the patients were treated with zirconia (Straumann® PURE Ceramic implants, Narrow Diameter, Straumann Institute, Basel, Switzerland; test group, n = 16) or titanium implants (Straumann Standard Plus Narrow Neck CrossFit®, Straumann Institute; control group, n = 14). One implant was placed in each patient in a healed site. Both implant types had a diameter of 3.3 mm in the intraosseous portion and 3.5 mm of shoulder diameter and a polished collar of 1.8 mm height. The length of the implants was 8, 10 and 12 mm. The implants were provisionally restored 4 days after placement with a resin crown. A cementable right angle 0° abutment (NNC Straumann abutment®, Institut Straumann, Basel, Switzerland) was placed on the control implants (Figure 1). Twelve weeks after implant placement, the final restorations were cemented for both study groups (baseline). A detailed study schedule is shown in Figure 2 (Ruiz Henao et al., 2021). 2.3 | Outcome measures Clinical followup examinations were conducted at 12, 36, and 60 months after implant loading. During each visit, various clinical parameters including probing pocket depth (PPD), bleeding on probing (BOP), and plaque index (PI) were assessed. Esthetic outcomes were also evaluated, including the ICAI and the pink esthetic score (PES). Radiographic assessment of marginal bone levels (MBL) was also performed during these examinations. Any biological or mechanical complication was recorded with the objective of evaluating the survival and success rates (Lang et al., 2012; Schwarz et al., 2018). To evaluate the status of the implant at 5 years of followup, survival and success rates were used. Survival rate was defined as the percentage of implants that remain functional over time, expressed as a percentage. Success rate was interpreted as the presence of the restoration with the implant free of biological or mechanical complications. Biological complications were considered when BOP was present (periimplant mucositis), with or without increased PPD and radiographic bone loss (periimplantitis) (Schwarz et al., 2018). Mechanical complications were categorized as follows: (a) major complications, when restoration replacement was required, which included cases of implant fracture, prosthesis fracture, or suprastructure loss; (b) medium complications, encompassing abutment, veneer and framework fracture, or phonetic complications; and (c) minor complications, such as screw loosening, loss of crown retention, decementation, and loss of screw hole sealing (Lang et al., 2012). 2.4 | Primary outcome The ICAI was considered as the primary outcome of this study. It consists of the analysis of nine different parameters associated with the implantsupported crown (ICAI crown) and the periimplant soft tissues (ICAI mucosa) that provide an overall result (ICAI total). For the ICAI crown, five parameters were analyzed: mesiodistal dimension of the crown, position of the incisal edge, labial convexity of the crown, color and translucency of the crown, and surface of the crown. For the ICAI mucosa, four parameters were analyzed: position of the labial margin, position of the interproximal papilla, mucosa labial contour, and color and surface of the labial mucosa. The contralateral tooth was used as a reference during the analysis. Penalty points were assigned to each parameter according to the following scores: 0 = excellent; 1 or 2 = satisfactory; 3 or 4 = moderate; 5 or more = poor esthetics (Meijer et al., 2005). The evaluation of this index was carried out by a blind examiner (C.A.M.B.) based on the photographs taken during the visits. No editing was performed on the photographs prior to evaluation. The photographs to assess esthetic indices were taken by placing the camera perpendicular to the buccal surface of the crown. Photographs were taken with a separator and had to include the incisal edge of the restoration and at least 5 mm of soft tissue. Occlusal photographs were also taken to evaluate the buccal convexity of the crown and the buccal contour of the periimplant mucosa. Natural light, supplemented by an annular flash coupled to the camera, was employed for consistent illumination. The camera used was digital (Canon 500D, Canon Inc), with a 100 mm macro (Canon Inc) and a ring flash (Canon MR14EX, Canon Inc). 2.5 | Secondary outcomes A modification of the PES was used to evaluate the soft tissue esthetics around the implant (Belser et al., 2009). This index analyses five soft tissue related variables, which include: mesial papilla, distal papilla, curvature of the facial mucosa, level of the facial mucosa, and root convexity/soft tissue color and texture at the facial aspect of the implant. After calibration with an experienced researcher (A.L.), one examiner (G.L.M.) performed this analysis clinically, during the followup appointments. After analyzing the variables independently, values were summed up for an index per implant. A maximum score of 10 was considered as optimum conditions and a total score of 6 was considered acceptable. In addition, a numerical scale was used to assess overall esthetic result from a professional standpoint, in which a number from 0 (very negative) to 10 (extremely positive) was assigned by a clinician (G.L.M.) (de Bruyn et al., 1997). Some secondary outcome variables including modified plaque index, modified bleeding on probing index, and PPD (Mombelli et al., 1987) were evaluated with a periodontal probe UNC15 (HuFriedy®). The MBL measurements were obtained from periapical radiographs, acquired using the longcone parallel technique (Walton & Layton, 2018). Radiographic parallelizers were employed, and an individualized silicone key was crafted upon the placement of the final crown at the baseline, ensuring consistent positioning. During subsequent followup visits, the silicon key was consistently repositioned using the same technique. One examiner (G.L.M.) using an image processing software (ImageJ, National Institutes of Health) 16000501, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/clr.14319 by Consorcio Interuniversitario Do Sistema Universitario De Galicia (Cisug), Wiley Online Library on [10/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 4 | RUIZ HENAO et al. was responsible for calculating MBL. This was estimated by measuring the distance from the implant shoulder to the first bonetoimplant contact, both mesially and distally, in millimeters. To improve the accuracy, each measurement was performed three times. A mean calculation was then carried out per implant. Measurements were made without subtracting the 1.8 mm polished neck length of the tissue level implant. Marginal bone levels changes were estimated by the difference between the baseline and 1, 3, and 5years evaluation. Patientreported outcome measures (PROMs) were used to evaluate patient satisfaction, and were structured in the form of questionnaires applied to patients, with a focus on the following aspects: satisfaction with esthetics, satisfaction with phonetics, satisfaction with comfort, satisfaction with chewing ability, and overall satisfaction (de Bruyn et al., 1997). A 10grade numeric scale was used to classify their impression/experience in each of the parameters from 0 (very negative) to 10 (extremely positive). FIGURE 1 Photographic and radiological records of two patients belonging to the test (a) and the control group (b) during the different followup moments (baseline, 1, 3 and 5 years). 16000501, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/clr.14319 by Consorcio Interuniversitario Do Sistema Universitario De Galicia (Cisug), Wiley Online Library on [10/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License | 5 RUIZ HENAO et al. 2.6 | Statistical analyses Continuous data were presented as mean and standard deviation (SD), unless specified otherwise. All analyses were conducted in the intentiontotreat (ITT) population, utilizing the last measure carried forward approach for handling missing values. A perprotocol population was defined as all participants in the ITT population with at least one efficacy assessment unaffected by protocol violations. Perprotocol analyses were performed for all outcomes, with estimates reported for the primary outcome (ICAI) and any secondary or posthoc outcomes differing from those obtained in the ITT population. Primary and secondary outcomes were introduced using general linear models (analysis of variance, ANOVA) for repeated measurements between groups, with posthoc comparisons conducted using the Bonferroni test. Categorical data were reported as percentages and compared using Friedman's test and Pearson's chisquare test. Survival and success rate analysis was performed using the Kaplan–Meier method. Statistical analyses were carried out using appropriate software (IBM SPSS Statistics version 24.0 for Windows, IBM Corporation, Armonk, NY, USA), with a significance level set at p < .05. 3 | RESULTS 3.1 | Demographic data Out of the initial 43 patients considered for the trial, nine were not eligible based on inclusion criteria, and four declined to participate for personal reasons. Consequently, a total of 30 patients were FIGURE 2 Flow diagram of the 5year followup study. 16 d crown assessed for eligibility xcluded -Exclusion criterionn=9 - 30 enrolled and randomly assigned 16 assigned to test group14 assigned to controlgroup Surgical phase 14 d crown Baseline 12 weeks 16 ceramic implants 12 months 14 ceramic implants (per-(per-36 months -1 lost to follow-up at 18 months -1 lost to follow-up at 30 months -1 lost to follow-up at 30 months 11 ceramic implants (perprotocol 11 (per60 months 16 ceramic implants -to-treat analysis) -to-treat analysis) -2lost to follow-up at 42 months -1 lost to follow-up at 54 months 2 -1lost to follow-up at 48 months -1 lost to follow-up at 54 months 16000501, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/clr.14319 by Consorcio Interuniversitario Do Sistema Universitario De Galicia (Cisug), Wiley Online Library on [10/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 6 | RUIZ HENAO et al. enrolled, with 16 assigned to the test group and 14 to the control group. Implant placement occurred between March 2016 and June 2017. At the 1year followup visit, all 30 patients completed the study (Ruiz Henao et al., 2021). Subsequently, followup visits were scheduled at 36 and 60 months. Between years 1 and 3, there were three dropouts from followup, two from the test group and one from the control group. Over the entire 5year followup period, there were a total of eight dropouts, with five occurring in the test group and three in the control group (Figure 2). 3.2 | Esthetic assessments The results of the main variable, the ICAI score, are shown in Table 1 and Figure 3. The total value for the test group was 6.31 ± 3.24, 6.38 ± 3.64 and 5.25 ± 4.21 at 12, 36 and 60 months, respectively, while in the control group they were 6.07 ± 3.22, 6.42 ± 2.79 and 4.50 ± 2.98, respectively, which indicates a moderate to poor esthetics in this analysis. The differences were not statistically significant between groups (p > .05). However, there were a statistically significant intragroup differences in the total ICAI index both in the test and control groups, with the difference between the baseline and 60 months being 4.78 (95% CI 2.48–7.08) for the control group and 3.68 (95% CI 1.53–5.84) for the test group. Analyzing the results of the ICAI index at crown (ICAI crown) or mucosa level (ICAI mucosa) a tendency to decrease the value was observed (Table 1). The intergroup score difference in the ICAI crown was 0.24 (95% CI 1.39–1.88), with no statistically significant differences between groups at 5 years (p = .76). For the ICAI mucosa, the score difference was 0.57 (95% CI 2.35–1.12), with no statistically significant differences between groups at 5year followup (p > .05). The detailed analysis of the nine parameters of the ICAI TABLE 1 Frequency of distribution (percentage/absolute number related to group) and changes of the ICAI index between ceramic and titanium implants over 5 years of followup. Ceramic implants (n = 16) Titanium implants (n = 14) pValueNo Slight Major No Slight Major ICAIcrown 60 months Mesiodistal dimension 6 (37.5) 9 (56.25) 1 (6.25) 6 (42.85) 8 (57.14) 0 (0) .32 Position incisal edge 10 (62.5) 5 (31.25) 1 (6.25) 7 (50.0) 7 (50.0) 0 (0) .17 Labial convexity 9 (56.25) 7 (43.75) 0 (0) 8 (57.14) 6 (42.85) 0 (0) .62 Color and translucency 8 (50.0) 8 (50) 0 (0) 7 (50.0) 7 (50.0) 0 (0) .99 Crown surface 11 (68.75) 5 (31.25) 0 (0) 9 (64.28) 5 (35.71) 0 (0) .79 ICAImucosa 60 months Position labial margin 10 (62.5) 6 (37.5) 0 (0) 9 (64.28) 5 (35.71) 0 (0) .88 Position papilla 8 (50.0) 7 (43.75) 1 (6.25) 6 (42.85) 8 (57.14) 0 (0) .72 Contour labial surface 9 (56.25) 5 (31.25) 2 (12.5) 9 (64.28) 5 (35.71) 0 (0) .50 Color and surface 11 (68.75) 5 (31.25) 0 (0) 11 (78.57) 3 (21.43) 0 (0) .60 Mean 95% CI Mean 95% CI ICAIcrown Baseline 4.06 (3.01–5.11) 4.07 (2.94–5.19) .99 12 months 3.94 (3.03–4.83) 3.64 (2.68–4.60) .65 36 months 3.63 (2.65–4.59) 3.64 (2.60–4.68) .98 60 months 2.81 (1.69–3.93) 2.57 (1.37–3.76) .76 ICAImucosa Baeline 4.87 (3.61–6.13) 5.21 (3.86–6.56) .71 12 months 2.38 (1.16–3.58) 2.36 (1.06–3.65) .98 36 months 2.75 (1.32–4.17) 2.79 (1.26–4.31) .97 60 months 2.50 (1.28–3.72) 1.93 (0.62–3.23) .51 I C A I - t o t a l Baseline 8.93 (6.98–10.88) 9.28 (7.20–11.37) .80 12 months 6.31 (4.65–7.96) 6.07 (4.30–7.84) .84 36 months 6.38 (4.69–8.05) 6.42 (4.63–8.22) .96 60 months 5.25 (3.35–7.14) 4.50 (2.47–6.52) .58 Note: No, no deviation, slight, slight deviation, major, gross mismatch. Mean and 95% confidence interval (CI) of the ICAIcrown, ICAImucosa and ICAItotal. pValue statistically significant ≤.05. 16000501, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/clr.14319 by Consorcio Interuniversitario Do Sistema Universitario De Galicia (Cisug), Wiley Online Library on [10/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License | 7 RUIZ HENAO et al. index at 5 years of followup did not show statistically significant intergroup differences in any of them (p > .05) (Table 1). In the perprotocol analysis of the main variable (ICAI index) at 60 months (Table 1), a total index of 5.18 (95% CI 2.69–7.66) was obtained for the control test and 4.09 (95% CI 1.60–6.57) for the control group, which means poor and moderate esthetics, respectively. No statistically significant differences were observed between groups (p > .05). Values for the ICAI crown were 2.27 (95% CI 1.03–3.50) and 2.09 (95% CI 0.85–3.32) for the test group control group, respectively. No statistically significant differences were observed between groups (p > .05). Within the test group statistically significant differences were observed between the 60month visit and the baseline (mean difference of 2.0 [95% CI 3.98–0.19]) and between the 60month and the 12month visit (mean difference of 1.90 [95% CI 3.78–0.31]). The values for ICAI mucosa at 60 months were 3.0 (95% CI 1.37–4.62) for the test group and 2.0 (95% CI FIGURE 3 Graphic representation of the mean value and 95% confidence intervals of the ICAI subdivided into ICAI mucosa, ICAI crown and total ICAI scores at the baseline, 1, 3 and 5 years. 16000501, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/clr.14319 by Consorcio Interuniversitario Do Sistema Universitario De Galicia (Cisug), Wiley Online Library on [10/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License 8 | RUIZ HENAO et al. 0.37–3.62) for the control group. There were no statistically significant differences between groups (p > .05). In the control group there was a difference of 2.72 (95% CI 4.30–1.15) between 60 months and the baseline, this being statistically significant (p < .001). In the test group there was also a statistically significant difference (p = .004) in the mucosa ICAI value between 60 months and the baseline with a mean difference of 2.18 (95% CI 3.75–0.60). Table 2 and Figure 4 showed the results of the esthetic analysis based on the secondary variables of PES, numerical scale by a dental professional, and PROMs by the patients. The PES showed a total value at 5 years of followup of 7.44 ± 1.93 and 7.43 ± 1.74 for the test and control groups, respectively, with no statistically significant differences between groups (p > .05). These scores indicated a clinically acceptable pink esthetics. Within the control group, a difference in the PES value between the baseline and 60 months of 1.07 (95% CI 2.43–0.29) was observed, with a statistically significant difference (p = .002). Meanwhile, in the test group, the difference was 0.68 (95% CI 1.96–0.58), also existing statistically significant differences over time (p = .020). The results of the perprotocol analysis of PES also showed a clinically acceptable esthetic result at the 5year followup, with an index of 6.91 (95% CI 5.66–8.15) for the test group and 7.09 (95% CI 5.85–8.33) for the control group. There were no statistically significant differences between groups (p > .005). In this analysis, no intragroup difference was observed between the 60month visit and the remaining visits in either of the two study groups. There were no statistically significant differences in numerical scale esthetic score between groups at 5year followup (p = .350). Similarly, there were no statistically significant differences between groups in the different values evaluated by the patient in the PROMs. 3.3 | Radiographic and clinical assessment Marginal bone levels were summarized in Table 3. After 5 years of followup, zirconia implants were associated with an MBL of 2.35 mm (95% CI 1.83–2.34), with the corresponding value for titanium implants being 2.76 (95% CI 2.20–3.32). There were no statistically significant differences between groups at any time of the study. In the control group, there was a mean difference of 1.02 mm (95% CI 1.77–0.28) between the baseline visit and 5 years, being statistically significant (p = .003). Between 1and 5year visit, there was a statistically significant difference of 0.80 mm (95% CI 1.46–0.13; p = .011). However, this was not observed in the test group, in which the mean difference between the baseline and 5 years assessment was 0.54 (95% CI 1.23–0.15) and between 1 and 5 years was 0.27 (95% CI 0.89–0.34), being not statistically significant in any of the cases. The mean MBL observed In the perprotocol analysis at 60 months was 2.99 mm (95% CI 2.32–3.66) in the control group and 2.57 mm (95% CI 1.90–3.25) in the test group. No statistically significant differences were observed between groups. In the control group, a statistically significant intragroup difference (p = .003) was observed between the 60month visit compared to the baseline with a mean difference of 1.27 mm (95% CI 0.37–2.17). Also in the control group, a statistically significant difference (p = .009) was observed between the 60 and 12month visit with a mean difference of 1.01 mm (95% CI 0.21–1.82). Mean probing depth at 5year followup for zirconia implants was 3.09 mm (95% CI 2.66–3.52) and 3.51 mm (95% CI 3.05–3.98) for titanium implants. There were no statistically significant differences between groups (p > .05). The plaque index at 5 years evaluation was 0.50 (95% CI 0.70–0.93) and 0.86 (95% CI 0.39–1.31) for test and control groups, respectively. Bleeding on probing was 1.31 (95% CI 0.75–1.88) for the test group, and 1.93 (95% CI 1.32–2.53) for the control group. There were no statistically significant differences for either of these two parameters at 60month followup (Table 3). After 5 years in function, three minor mechanical complications were recorded in each group, all due to debonding of the crown (Table 4). In relation to biological complications, at 5 years of followup, there were 31.25% of complications in the test group and FIGURE 3 (Continued) 16000501, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/clr.14319 by Consorcio Interuniversitario Do Sistema Universitario De Galicia (Cisug), Wiley Online Library on [10/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License | 9 RUIZ HENAO et al. 35.70% in the control group. Of these biological complications at 60 months, there were two cases of mucositis (12.50%) and three cases of periimplantitis (18.75%) in the test group, and three cases of mucositis (21.42%) and two cases of periimplantitis (14.28%) in the control group (Table 4). At 5 years of followup, there was no implant loss. However, taking into account the mechanical and biological complications described above, not all of them met the success criteria. Therefore, the overall survival and success rate in this University setting trial was 100% and 56.727% (95% CI 53.099–60.355) respectively at the implant level at 5 years of followup. In the test group the success rate was 55.636% (95% CI 49.520–61.752) and in the control group 57.818% (95% CI 53.260–62.377) at 5 years. 4 | DISCUSSION The main objective of the present randomized clinical trial was to compare the esthetic results of zirconia compared to titanium implants when placed in the esthetic region. The results of this publication with a 5year followup did not show statistically significant differences between groups in any of the variables during the followup time. This reaffirms the results obtained after the first year, highlighting zirconia implants as a valuable option for the esthetic sector. Recent publications on zirconia implants have demonstrated, much like the results obtained in this trial, that over an extended followup period, zirconia implants offer a reliable alternative (Borgonovo et al., 2021; Bradley et al., 2021; GargalloAlbiol et al., 2022; Kiechle et al., 2023). These favorable outcomes were achieved using onepiece implants similar to those employed in this study. Upon analyzing the esthetic results after 5 years of function, it becomes apparent that both groups exhibit significant improvement in all evaluated parameters over time in the ICAI. Although similar clinical trials that compared zirconia versus titanium implants are lacking, a recent study (Carrillo de Albornoz et al., 2014; Ferrantino et al., 2023) compared titanium and zirconia abutments, evaluating the ICAI parameters The findings of that investigation revealed a significant worsening in the ICAI Crown value over a 5year followup period, with values of 4.18 ± 3.43 and 5.64 ± 4.33 for test and control groups, respectively. Conversely, in our trial, an inverse trend was observed, indicating a nonstatistically significant improvement over time in both groups, with values of 2.81 ± 2.56 and 2.57 ± 1.65, respectively. Regarding ICAI mucosa, the aforementioned study reported values of 3.64 ± 1.36 and 5.93 ± 2.27 for the test and control group, respectively, and a clear difference in soft tissue response was observed favoring zirconia abutments. Interestingly, in our study, while a greater improvement in parameters associated with soft tissues over time was observed, no differences were observed between the groups. TABLE 2 Frequency of distribution (percentage/absolute number related to group) and changes of the PES. PROMs between titanium and ceramic implants over 5 years of follow up. Ceramic implants (n = 16) Titanium implants (n = 14) Intergroup Complete Incomplete Absent Complete Incomplete Absent pValue PES 60 months Mesial papilla 7 (43.75) 9 (56.25) 0 (0) 4 (28.57) 10 (71.42) 0 (0) .38 Distal papilla 7 (43.75) 7 (43.75) 2 (12.5) 3 (21.42) 11 (78.57) 0 (0) .11 Curvature of facial mucosa 9 (56.25) 6 (37.5) 1 (6.25) 8 (57.14) 6 (42.85) 0 (0) .62 Level of facial mucosa 10 (62.5) 6 (37.5) 0 (0) 11 (78.57) 2 (14.28) 1 (7.14) .23 Root convexity/soft tissue color and texture 8 (50.0) 6 (37.5) 2 (12.5) 10 (71.42) 2 (14.28) 2 (14.28) .35 Mean 95% CI Mean 95% CI Overall PES baseline 6.75 (6.03–7.46) 6.35 (5.59–7.11) .44 Overall PES score 12 months 7.81 (7.02–8.60) 7.85 (7.06–8.69) .93 Overall PES score 36 months 7.62 (6.48–8.76) 7.43 (6.20–8.64) .81 Overall PES score 60 months 7.44 (6.49–8.38) 7.43 (6.41–8.43) .99 Overall VAS value 60 months (NS) 8.13 (7.30–8.94) 7.57 (6.69–8.44) .35 PROMs 60 months Esthetic 9.37 (8.83–9.91) 9.07 (8.49–9.64) .43 Speaking 9.75 (9.43–10.06) 9.43 (9.09–9.76) .16 Comfort 9.63 (9.27–9.97) 9.43 (9.05–9.80) .44 Chewing ability 9.44 (9.03–9.84) 9.14 (8.70–9.57) .31 General satisfaction 9.63 (9.22–10.00) 9.43 (9.00–9.85) .49 Note: Mean and 95% confidence interval (CI) of the overall score of PES, VAS and PROMs parameters. 16000501, 0, Downloaded from https://onlinelibrary.wiley.com/doi/10.1111/clr.14319 by Consorcio Interuniversitario Do Sistema Universitario De Galicia (Cisug), Wiley Online Library on [10/07/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License