International Journal of Oral Implantology, 02/2021

Purpose: To evaluate the crestal bone loss and implant stability quotient trends of photofunctionalised versus untreated implants. Materials and methods: A total of 34 patients (age 46.94 ± 12.03 years) with bilateral single missing teeth in the same arch were enrolled in this study. Each patient received an untreated implant on one side (control group, n = 34) and a photofunctionalised implant on the contralateral side (test group, n = 34). Crestal bone loss was assessed at the time of crown insertion and 1 year later. The osseointegration speed index was evaluated for both the control and test group. An independent t test was used for intergroup comparisons of crestal bone loss and osseointegration speed index. Bivariate analysis was performed for the confounding variables. Results: The test group showed a statistically significantly higher osseointegration speed index (3.07) as compared to the control group (1.29) (P < 0.01). Statistically significantly higher crestal bone loss was observed in the control group (−0.57 ± 0.41 mm) as compared to the test group (−0.27 ± 0.35 mm) (P < 0.01). The difference between mean Plaque Index and Bleeding Index in the control (0.74/0.38) and test group (0.73/0.35) was statistically insignificant (P > 0.05). A negative correlation (r = −0.272) was noted between implant diameter and crestal bone loss. A positive correlation (r = 0.402) was observed between implant length and osseointegration speed index. Conclusion: Implants with photofunctionalised surfaces reduce overall healing time and crestal bone loss. Photofunctionalisation is an effective aid for chairside conditioning of implant surfaces to achieve faster osseointegration with good crestal bone stability. Keywords: crestal bone loss, implant stability, surface treatment Conflict-of-interest statement: The authors declare there are no conflicts of interest related to this study.

Purpose: To investigate the effect of laser microtextured collars or laser microtextured abutments on clinical measures that may relate to improved implant success and survival. Materials and methods: This review was registered on the PROSPERO database and conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. MEDLINE (via PubMed) and Embase were screened for studies with at least 10 participants and followed up for at least 1 year, reporting on the following clinical outcomes: radiographic marginal bone level, peri-implant probing depth, soft tissue index and failure rates of implants with laser microtextured collars or laser microtextured abutments. The quality of the studies was assessed using the Cochrane risk-of-bias tool or the Newcastle-Ottawa scale. Results: After removal of duplicates, 86 articles were identified. A total of 25 articles were included after screening. Four were randomised controlled trials, two were non-randomised controlled trials, two were prospective studies, five were retrospective cohort studies and twelve had no control group. Most comparative studies reported that laser microtextured collar implants had less marginal bone loss and shallower peri-implant probing depth than machined collar implants. Only two studies had controls other than machined collar implants; in these, the use of laser microtextured collar implants was not observed to be significantly different. Three studies reported reduced marginal recession in laser microtextured collar implants when compared to machined collar controls. No difference in failure rate was observed between laser microtextured collar and machined collar implants. One study reported on peri-implant diseases and favoured laser microtextured collar implants. Three papers reported using laser microtextured abutments with no control, but no specific conclusions could be drawn. Conclusions: Laser microtextured collar implants appear to reduce marginal bone loss and peri-implant probing depth when compared to machined collar implants. There is weak evidence to suggest that laser microtextured collar implants may also improve aesthetic outcomes and reduce incidence of disease. Research is required regarding laser microtextured abutments, and studies comparing laser microtexturing with alternative solutions are also lacking. Keywords: dental implants, implant survival, laser microgrooved, laser microtextured, marginal bone loss, soft tissue stability, systematic review Conflict-of-interest statement: The authors declare there are no conflicts of interest related to this study.

Purpose: To evaluate the accuracy of full-arch digital implant impressions taken using intraoral scanners and analyse the related variables. Materials and methods: An electronic search of studies on the accuracy of digital implant impressions in fully edentulous arches from 1 January 2012 to 29 February 2020 was conducted in PubMed, EMBASE and the Cochrane Library. Only peer-reviewed experimental or clinical studies written in English were included. Studies assessing the accuracy of restorations, case reports, clinical reports, technical reports and reviews were excluded. The literature screening, article reading and assessment of risk of bias were carried out by two reviewers. The data on the study characteristics, accuracy outcomes and investigated variables were extracted. Results: After removal of duplicates, a total of 166 studies were identified, of which 42 were initially selected for full-text reading and 30 were included in the final analysis (29 in vitro studies and one in vivo study). The trueness of digital implant impressions ranged from 7.6 to 731.7 μm, and the precision ranged from 15.2 to 204.2 μm. Angular deviations were between 0.13 and 10.01 degrees. Considering 100 μm and 0.4 degrees as clinically acceptable levels of deviation, 18 studies reported linear/distance/3D deviations larger than 100 μm and only two studies reported angular deviations below 0.4 degrees. The effect of interimplant distance/length of the arch scanned/scanning sequence/scanning range/implant position (nine studies), implant angulation (ten studies), implant depth (five studies), implant connection (two studies), operator experience (six studies), scan body type (three studies), intraoral scanner type (six studies), scanning strategy (two studies) and modification technique (three studies) was investigated. Conclusions: Based on the results of the included studies, full-arch digital implant impressions taken using intraoral scanners are not sufficiently accurate for clinical application. Accuracy varies greatly with interimplant distance, scan body type, intraoral scanner type and operator experience, whereas implant angulation, implant connections and implant depth have no effect. The effects of scanning strategy and modification technique need further investigation. Keywords: accuracy, dental impression technique, digital impressions, edentulous, intraoral scanner Conflict-of-interest statement: The authors declare there are no conflicts of interest related to this study.

Purpose: To investigate the use of platelet-rich fibrin for alveolar ridge preservation compared to natural healing, bone graft material and platelet-rich fibrin in combination with bone graft material. Materials and methods: The present systematic review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The review examined randomised controlled trials comparing the clinical outcomes of platelet-rich fibrin with those of other modalities for alveolar ridge preservation. Studies of third molar extraction site healing were excluded. The studies were classified into three categories: natural wound healing vs platelet-rich fibrin; bone graft material vs platelet-rich fibrin; and bone graft material vs bone graft material and platelet-rich fibrin. Results: From 179 articles identified, 16 randomised controlled trials were included. Owing to the heterogeneity of the investigated parameters, it was not possible to perform a meta-analysis. In total, 10 randomised controlled trials compared platelet-rich fibrin to natural wound healing, with seven of these demonstrating favourable outcomes to either limit postextraction dimensional changes or improve new bone formation in the platelet-rich fibrin group. Three of four studies comparing healing with bone graft material to platelet-rich fibrin found that the latter led to significantly greater horizontal or vertical bone resorption, and the bone graft material was more able to maintain the ridge dimensions. Two out of three randomised controlled trials investigating healing with both bone graft material and platelet-rich fibrin reported better outcomes using this combined approach than with bone graft material alone. All studies investigating soft tissue healing with platelet-rich fibrin demonstrated better outcomes in the platelet-rich fibrin group. Conclusions: The majority of studies comparing healing with platelet-rich fibrin to natural healing concluded that the former more successfully limits postextraction dimensional changes than the latter. However, 75% of studies investigating platelet-rich fibrin vs bone graft material reported better results in the bone graft group with respect to its ability to maintain postextraction dimensional changes. The addition of platelet-rich fibrin to bone graft material may improve clinical outcomes, although data are limited. Keywords: advanced platelet-rich fibrin, alveolar ridge preservation, biomaterials, extraction site management, growth factors, leucocyte- and platelet-rich fibrin, platelet concentrates, platelet-rich fibrin, systematic review Conflict-of-interest statement: Richard J Miron holds intellectual property on platelet-rich fibrin. All other authors declare no conflicts of interest related to this study.

Purpose: To assess the fit and cement gap of fixed partial dentures supported by two implants made using conventional and digital workflows. Materials and methods: Patients requiring fixed partial dentures supported by two implants were included in the study. Forty-eight zirconia fixed partial denture bars supported by two implants (AnyOne, MegaGen, Daegu, South Korea) were produced using a conventional (n = 24, group C) and digital (n = 24, group D) workflow. All implants had the same internal connection prosthetic platform. Silicone open tray impressions with splinted copings (group C) and digital impressions using a Trios 3 intraoral scanner (3Shape, Copenhagen, Denmark) (group D) were taken for each patient. The fit and cement gap were assessed by scanning electron microscopy on the verified master cast. The distance between reference points on the titanium base and implant analogue was measured with and without tightening the prosthetic screw. The difference in distance was calculated and represented the misfit (Dmisfit). The cement gap (Dcement) was measured as the shortest vertical distance from the inferior edge of the bar to the top edge of the titanium base. Results: The median Dmisfit values (interquartile range) differed significantly (P < 0.05) between the groups, with 59 (60) µm for group C and 78 (88) µm for group D. Fixed partial dentures fabricated using a digital workflow presented lower Dcement values (35 [26] µm) than the conventional group (38.9 [23] µm) (P < 0.05). Conclusions: Both workflows produced different levels of fit and differently sized cement gaps when measured on the master casts using scanning electron microscopy. A cast-free digital workflow was associated with a smaller cement gap, but larger misfit was detected when measuring on the verified master cast. Keywords: Key words, cement gap, digital impression, implant prosthodontics, passive fit, , ABSTRACT Conflict-of-interest statement: The authors declare there are no conflicts of interest related to this study.

Achieving predictable success with implants in the aesthetic zone is essential for clinicians. Promoting marginal bone and stability of the gingival environment is key to obtaining a predictable aesthetic outcome. The present study aimed to describe a technique that combines a flapless approach to immediate extraction and placement of sloped implants, using an acellular dermal matrix to contain the coronal aspect of a deproteinised bovine bone mineral graft. This minimally invasive technique results in stable augmentation of soft tissue thickness to ensure predictable aesthetic results. A collection of case reports with a follow-up period of up to 45 months is presented to demonstrate the surgical technique. Clinical presentation showed relative stability of the soft tissue margins during the evaluation period. Keywords: aesthetics, bone graft, immediate placement, single implant, surgical procedure Conflict-of-interest statement: The authors declare there are no conflicts of interest relating to this study.