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This prospective, preliminary controlled clinical trial investigates the comparative effectiveness of platform-switching (PS) versus traditional butt-joint or platform-matching (PM) implant-abutment connections on peri-implant crestal bone stability. Utilizing a split mouth design, 10 systemically healthy patients (n= 20 implants) had adjacent non-restorable maxillary anterior teeth replaced with two different implants (butt-joint connections and platform-switching interfaces). Patients underwent alveolar ridge preservation, followed by implant placement: platform-matching implants were inserted at crestal bone level, and platform-switching implants were placed 1mm subcrestally. Customized Zirconia crowns were then fabricated for both systems. Outcome measures included bleeding on probing (BOP), probing pocket depth (PPD), and marginal bone loss (MBL), which were evaluated through standardized periapical radiographs over 3-year timeframe. Results showed significantly higher initial MBL in the PM group (0.86 ± 0.13 mm) compared to the PS group (0.34±0.29 mm) [p value: p<0.01]. Moreover, at the three-year follow-up, the crestal bone levels remained above the implant shoulder until the third year of the study for the PS subcrestal group (PS: -0.15±0.39 mm) and slightly below the implant platform in the PM crestal group (PM: 0.55±0.19). After 3 years, the PS group also exhibited lower mean BOP percentages (12%) than the butt-joint group (17%). This study suggests that subcrestal placement with PS and internal connections can provide better long-term peri- implant bone preservation, thereby potentially improving implant success and aesthetic outcomes in the anterior maxillary region. Keywords: dental implant, abutment, dental implant-abutment connection, platform-switching, platform-matching, implant-supported dental prostheses, marginal bone levels

Purpose: To evaluate the preferences of dental practitioners for tooth-supported crowns dental ceramics by means of an online survey and to assess the influence of age, gender, years of experience, and dental specialty on those preferences. Materials and Methods: An anonymous questionnaire was delivered online through Google Surveys, targeting 796 dentists. It contained 17 dichotomous, closed questions with two sections. The first section dealt with general characteristics, including age, gender, years of experience, training in prosthodontics, and hours worked per week. The second section included questions regarding preferences of different materials for crowns, and the use of digital workflows. Analyses were carried out with Stata 14.0 software (StataCorp, TX, USA). A significance level of p=0.05 was adopted. Results: 248 surveys were answered. Practitioners in Chile preferred lithium disilicate for the anterior region (55.2%) but also for the posterior area (40.7%), regardless of their age, gender, years since graduation, hours worked per week or any training in prosthodontics. Chilean dentists over 50 years old considered zirconia almost 4 times more than those under 30 years old for anterior crowns (51.85%). 59.68% of dentists take digital impressions, and 37.10% have access to chairside CAD/CAM technology. In this group, 54.4% preferred feldspathic ceramic for anterior and 23.9% for posterior crowns. Conclusions: While there is a wide range of dental ceramic materials, these results provide a snapshot of the current trends in Chile where lithium disilicate is the most preferred ceramic material for tooth-supported crowns, and metal-ceramic is the least preferred material. Keywords: Ceramics, survey, zirconia, CAD/CAM, questionnaire

Ziel: Ziel dieser retrospektiven Fallserie war eine Längsschnittuntersuchung der Volumenveränderungen des vestibulären Weichgewebevolumens an Implantaten bezogen auf die Dicke und die Breite der keratinisierten Mukosa (DKM bzw. BKM) nach Weichgewebeaugmentation mittels Bindegewebetransplantat (BGT) und mikrochirurgischer Envelope-Technik. Material und Methoden: Bei 12 gesunden Patienten wurden 12 Implantate im Ober- oder Unterkieferseitenzahnbereich eingesetzt. Die Studie umfasste die minimalinvasive Entnahme von 12 BGT mit einer Einzelinzisionstechnik und deren Transplantation zur Augmentation des vestibulären periimplantären Weichgewebes unter Verwendung einer Envelope-Technik. Anschließend wurden die Implantate mit 12 verschraubten Keramikkronen versorgt (IPS e.max). Ergebnisse: Die Heilung verlief an allen Implantaten unauffällig und die Patienten wurden anschließend 5 Jahre nachbeobachtet. Für die DKM war in den ersten 6 postoperativen Wochen der größte Rückgang zu beobachten (von 5,50 ± 0,79 mm auf 4,59 ± 0,62 mm); anschließend sank sie nochmals leicht ab (auf 4,00 ± 0,85 mm) und blieb bis zur 2-Jahres-Nachuntersuchung stabil (bei 4,00 ± 0,36 mm). Zwischen dem zweiten und dem dritten Jahr nach der Operation nahm die DKM nochmals ab (auf 3,59 ± 0,42 mm) und blieb dann bis zum Ende des 5-jährigen Beobachtungszeitraums konstant. Die Beobachtungen zur BKM waren hiervon leicht verschieden: Die Messungen zeigten, dass die größte Abnahme in den ersten 6 Wochen stattfand (von 2,50 ± 0,42 auf 1,50 ± 0,42 mm), und die BKM anschließend bis zur 1-Jahres-Nachuntersuchung gehalten wurde. Vom ersten zum zweiten Jahr nach dem Eingriff stieg die BKM wieder an (auf 2,00 ± 0,60 mm) und blieb während der nächsten 3 Jahre gleich (bei 2,00 ± 0,85 mm). Schlussfolgerungen: Die vorliegende Untersuchung konnte die Vorteile deutlich machen, welche die Kombination aus periimplantärer Weichgewebeaugmentation mittels eines minimalinvasiv entnommenen BGT und der mikrochirurgischen Envelope-Technik über einen Zeitraum von 5 Jahren bietet. Keywords: Bindegewebetransplantat, Envelope-Technik, Implantologie, Mikrochirurgie, periimplantäres Weichgewebe

Aim: The aim of the present retrospective case series was to longitudinally assess soft tissue volume changes on the vestibular aspect of implants in relation to keratinized mucosa thickness (KMT) and width (KMW) after the application of the microsurgical envelope technique combined with a connective tissue graft (CTG). Materials and methods: A total of 12 healthy patients received 12 dental implants placed either in the posterior maxilla or mandible. The study involved the harvesting of 12 CTGs with a minimally invasive single-incision technique, grafted to the vestibular peri-implant soft tissue utilizing the envelope technique, followed by the insertion of 12 screw-retained IPS e.max crowns. Results: The healing process was uneventful across all areas, and all patients were followed up for a period of 5 years. The evaluation of KMT showed the highest decrease in the first 6 weeks after surgery (5.5 ± 0.79 to 4.59 ± 0.62 mm), then dropped slightly to 4 ± 0.85 mm, after which it maintained at 4 ± 0.36 mm until the 2-year time point. Between the second and third years after surgery, a further decrease of 3.59 ± 0.42 mm was recorded for KMT, which then remained constant until the end of the 5-year research period. The observations regarding KMW were slightly different, with the measurements demonstrating the greatest decrease in first 6 weeks (from 2.5 ± 0.42 to 1.5 ± 0.42 mm), which was maintained until the 1-year time point. Between the first and second years after surgery, the KMW increased to 2 ± 0.60 mm and remained level for the next 3 years, at 2 ± 0.85 mm. Conclusions: The current research demonstrated the advantages of using a combination of a minimally invasively harvested CTG and the microsurgical envelope technique for a duration of 5 years. Keywords: connective tissue graft, envelope technique, implantology, microsurgery, peri-implant soft tissue

Purpose: To evaluate the performance of one- and two-piece ceramic implants regarding implant survival and success and patient satisfaction. Materials and Methods: This review followed the PRISMA 2020 guidelines using PICO format and analyzed clinical studies of partially or completely edentulous patients. The electronic search was conducted in PubMed/MEDLINE using Medical Subject Headings (MeSH) keywords related to dental zirconia ceramic implants, and 1,029 records were received for detailed screening. The data obtained from the literature were analyzed by single-arm, weighted meta-analyses using a random-effects model. Forest plots were used to synthesize pooled means and 95% CI for the change in marginal bone level (MBL) for short-term (1 year), mid-term (2 to 5 years), and long-term (over 5 years) follow-up time intervals. Results: Among the 155 included studies, the case reports, review articles, and preclinical studies were analyzed for background information. A meta-analysis was performed for 11 studies for one-piece implants. The results indicated that the MBL change after 1 year was 0.94 ± 0.11 mm, with a lower bound of 0.72 and an upper bound of 1.16. For the mid term, the MBL was 1.2 ± 0.14 mm with a lower bound of 0.92 and an upper bound of 1.48. For the long term, the MBL change was 1.24 ± 0.16 mm with a lower bound of 0.92 and an upper bound of 1.56. Conclusion: Based on this literature review, one-piece ceramic implants achieve osseointegration similar to titanium implants, with a stable MBL or a slight bone gain after an individual initial design depending on crestal remodeling. The risk of implant fracture is low for current commercially available implants. Immediate loading or temporization of the implants does not interfere with the course of osseointegration. Scientific evidence for two-piece implants is rare. Keywords: ceramic implants, implant survival, marginal bone level, systematic review, titanium implant

Xenogeneic-derived biomaterials are among the most routinely employed bone substitutes for immediate grafting of extraction sites as a modality of alveolar ridge preservation (ARP). The deproteinized bovine bone material is widely used and documented around the world. The present pilot clinical trial evaluated and compared the clinical and morphologic alterations of extraction sites after ARP using two commercially available yet differently processed bovine bone grafts. A total of 20 adjacent extraction sites in 10 patients were included. All sites received the exact same ARP therapy except for the type of bovine bone graft, which was randomly assigned between two adjacent extraction sockets in 10 patients (Group A received Bio-Oss particles and Group B received Cerabone particles). At all sites, healing was monitored at the time of surgery and at 1, 2, 3, and 4 months postoperative. All of the augmented extraction sites achieved successful implant therapy regardless of the bone graft material used for ARP. Six weeks after implant placement, second-stage/uncovering procedures were performed without complications. Intergroup comparisons of the crestal gingival healing process (CGHP), mean transversal crestal ridge resorption (MTRR), and mean implant primary stability (MIPS) were in favor of Group A sites (treatment with Bio-Oss particles). 

Digital dentistry has contributed to the evolution and simplification of dental implantology over the last decade. The incorporation of intraoral scanners, CBCT, 3D implant-planning software, and CAD/CAM systems makes prosthetically driven implantology a straightforward process. Such digital resources for treatment planning and execution, following evidence-based concepts, have the ability to improve the long-term esthetics and function of implant-supported restorations as well the long-term survival of dental implants. Dental implants are frequently considered as the first treatment option for replacing failing or missing teeth. However, their use in the esthetic zone remains a challenge for many clinicians. The present article provides clinical guidelines for ideal implant positioning employing computer-guided surgery and chairside CAD/CAM-fabricated provisional and definitive restorations with titanium (Ti)-bases for successful prosthetic outcomes, optimizing gingival architecture, and decreasing overall treatment duration. (Int J Comput Dent 2023;26(1):75–0; doi: 10.3290/j.ijcd.b3818287) Keywords: Dental implant, implant restoration, chairside, CAD/CAM, titanium base, implant position, immediate provisional, guided implant surgery

Background and aim: Dental implant patients are frequently required to undergo a second-stage/uncovery procedure to expose the implant fixture. The aim of the present prospective study was to evaluate the clinical outcomes of the vestibular split rolling flap (VSRF) versus the double door mucoperiosteal flap (DDMF) techniques at adjacent posterior implant sites during the second-stage procedure. Materials and methods: A total of 44 uncovered posterior dental implants in 10 healthy patients were treated at the second stage. All the mesial implants were assigned to the VSRF technique (group A) and the distal implants to the DDMF technique (group B). Soft tissue measurements were performed as vestibular keratinized mucosal width (KMW) and vestibular mucosal thickness (MT) over a period of 1 year, assessed at four different intervals. Results: Healing was uneventful at all sites. There were no patient dropouts in the entire study time frame. The clinical comparison of the adjacent implants showed overall higher MT measurements at 12 months for group A (2.5 ± 0.2 mm) compared with group B (1.00 ± 0.3 mm), and for KMW measurements for group A (2.5 ± 0.2 mm) compared with group B (2.0 ± 0.3 mm). Conclusions: The VSRF technique described in the present article is a reliable method for performing an implant uncovery. If the technique is applied according to the indication and with a minimally invasive protocol, it is preferable to other conventional exposure techniques due to its ability to provide enhanced soft tissue volume around the implant, which can in turn benefit the health, esthetics, function, and long-term stability of the peri-implant tissue.

Hintergrund und Ziel: In vielen Fällen ist nach einer Implantation ein zweiter Eingriff zur Freilegung der Implantatfixtur notwendig. Ziel der vorliegenden prospektiven Studie war ein Vergleich der klinischen Ergebnisse bei Anwendung folgender Freilegungstechniken an benachbarten Seitenzahnimplantaten: vestibulärer Teilschicht-Rolllappen (vestibular split rolling flap, VSRF) und Doppeltür-Mukoperiostlappen (double door mucoperiosteal flap, DDMF). Material und Methoden: Insgesamt 44 gedeckt eingeheilte Implantate bei 10 gesunden Patienten wurden bei einem Zweiteingriff freigelegt. Die jeweils mesialen Implantate wurden der VSRF-Technik (Gruppe A), die distalen der DDMF-Technik (Gruppe B) zugeteilt. Zur Bewertung des Weichgewebes wurden während eines Jahres an vier Zeitpunkten die Breite der vestibulären keratinisierten Mukosa (KMB) und die Dicke der vestibulären Mukosa (MD) gemessen. Ergebnisse: Die Heilung verlief an allen Implantaten unauffällig. Während der gesamten Studiendauer gab es keine Studienabbrüche. Im klinischen Vergleich der benachbarten Implantate ergaben sich nach 12 Monaten höhere MD-Werte in Gruppe A (2,5 ± 0,2 mm) als in Gruppe B (1,00 ± 0,3 mm) und höhere KMB-Werte in Gruppe A (2,5 ± 0,2 mm) als in Gruppe B (2,0 ± 0,3 mm). Schlussfolgerungen: Die im vorliegenden Artikel beschriebene VSRF-Technik ist ein zuverlässiges chirurgisches Verfahren zur Implantatfreilegung. Wird diese Technik indikationsgemäß und nach einem minimalinvasiven Protokoll angewendet, liefert sie im Gegensatz zu anderen konventionellen Freilegungstechniken ein größeres Weichgewebevolumen um Implantate. Dies wirkt sich günstig auf die Gesundheit, Ästhetik, Funktion und langfristige Stabilität des periimplantären Gewebes aus.

The purpose of this study was to investigate the effects of various titanium and zirconia polishing protocols on the colonization of oral bacteria. Titanium and zirconia discs were divided into five groups: unpolished (control, UNP) and polished with Brownie only (BRO), Brownie plus Greenie (BPG), Brownie plus Greenie plus Supergreenie (BGS), and CeraMaster Coarse plus CeraMaster polishing tips (CER). The samples were sterilized and immersed in unstimulated saliva, then incubated in a liquid suspension of Streptococcus gordonii (S gordonii). The number of attached bacteria were counted 48 hours after the diluted suspensions were inoculated. Data were analyzed with ANOVA and Tukey test (P < .05). For titanium discs, the average number of bacteria from each group (CFU/mm²) was 1.51 x 10³ for UNP; 3.71 x 10³ for BRO; 5.65 x 10³ for BPG; 8.99 x 10² for BGS; and 8.49 x 10² for CER. For zirconia, the averages were 2.87 x 10² for UNP; 3.16 x 10² for BRO; 3.50 x 10² for BPG; 1.83 x 10² for BGS; and 8.73 x 10¹ for CER. Inadequate polishing roughens surfaces and promotes microbial adhesion to titanium and zirconia. Sequential polishing to the finest-finish polishing tips minimizes bacterial adherence to abutment surfaces. Zirconia exhibited less bacterial adhesion than titanium.