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Background Primary and secondary implant stability is of high importance for survival and success of dental implants in the short and long term. Measurements of implant stability during healing provide the opportunity to monitor the course of the osseointegration process. Purpose To compare implant stability quotient (ISQ) by resonance frequency analysis (RFA), recorded with two different devices after implant placement. Materials and methods Patients with the need of single tooth extraction in posterior sites of the maxilla and the mandible were treated in a surgical center. All patients received additional augmentation with a bovine bone substitute and platelet-rich fibrin (PRF) after atraumatic tooth extraction. After a healing period of 10 weeks, 28 self-tapping titanium-implants were placed. Implant stability was recorded with two different devices (Osstell and Penguin) at the time of implant insertion (T0), 10 days later (T1), and after 7 (T2), or 17 weeks (T3). Results No implant was lost, and no postoperative complication occurred during follow-up. Patient cohort comprised 9 female (32.1%) and 19 male patients (67.9%), with a mean age of 52.8 years, 64.3 years, respectively. Mean overall insertion torque was 43.6 Ncm at implant placement with no significant difference between implant location, age, or gender. No patient dropped out. During observation period, a significant increase in mean ISQ was recorded with both devices. Significant positive correlations between insertion torque and ISQ were recorded with both devices at T0, T2, and T3. No significant differences were observed in ISQ-values between both devices, and measuring directions at any point of measurement. Conclusions Within the limitations of this cohort study, both devices were suitable for RFA-measurement and revealed comparable results. Due to the cordless design, handling of the Penquin device was more comfortable. Reusability of the Penguin MultiPeg-transducers may offer an additional benefit with regard on ecological aspects.

Statement of problem Implant-supported prostheses have typically been retained by cement or screws, each of which has advantages and disadvantages. Two new types of prosthesis with complementary advantages and disadvantages have been proposed: the screw- and cement-retained prosthesis, which combines cement and screw retention, and the antiloosening inner-post screw (ALIPS) type, which uses lateral screws. Both esthetic and functional factors should be considered for anterior prostheses; however, clinical studies of the complication rates of these designs are lacking. Purpose The purpose of this retrospective clinical study was to evaluate the complications of dental implant-supported restorations with various prosthetic types in the anterior region and to analyze other factors that affect complications. Material and methods This study included 51 patients who had 83 implants placed in the anterior region by a single clinician between August 2009 and December 2016. Surgical and prosthetic features were recorded, and implant complications were analyzed. Results There were 45 (55.4%) cement-retained implants, 5 (6.0%) screw- and cement-retained prosthesis implants, and 32 (38.6%) ALIPS-retained implants. Peri-implant mucositis was observed most frequently in the ALIPS type (21.9%), but the biological complications did not differ significantly with the prosthetic type. The most common mechanical complication was loss of retention in the cement type of prosthesis (30.4%) and screw loosening in the ALIPS type (43.8%). Implant complications varied with position (maxilla or mandible) and implantation timing (period from tooth extraction to implant placement). Conclusions The complications of implants placed in the anterior region were affected by different factors but did not differ significantly with the type of the retention.

This retrospective clinical study was conducted to evaluate the clinical usefulness of a freely removable microlocking implant prosthesis (MLP) that was developed to overcome the problems with conventional implant prostheses. A total of 54 patients (male: 31, female: 23) and 100 implant prostheses were included. Patients were divided into three groups such as 6-12 months, 12-18 months, and 18-24 months according to the used period after implant prosthesis delivery, and the patients in each group were recalled for examinations of survival rate, marginal bone resorption, peri-implant soft tissue indices, and complications. The prosthetic complications were analysed by combining the recorded chart data during the periodic checks including the last call for this study. During a 2-year observation period, all the implants showed a 100% survival rate without clinical mobility and functional problems. There was no significant difference in marginal bone resorption, plaque index, and bleeding index over the observation period after implant prosthesis delivery. Probing depth of the 18-24 months group (1.5±0.19 mm) was significantly lower than that of the 6-12 months group (p<0.05). The main complication was abutment loosening (4%), followed by implant prosthesis fracture (2%) and food impaction (2%) which were recorded. Within the limits of the present study, the implant prostheses with MLP are considered to be an applicable and predictable treatment method.

Objectives To examine the retention force of removable dental prosthesis (RDP) clasps made from polyetheretherketone (PEEK) and cobalt-chrome-molybdenum (CoCrMo, control group) after storage in water and artificial aging. Materials and methods For each material, 15 Bonwill clasps with retentive buccal and reciprocal lingual arms situated between the second pre- and first molar were manufactured by milling (Dentokeep [PEEKmilled1], NT digital implant technology; breCAM BioHPP Blank [PEEKmilled2], bredent), pressing (BioHPP Granulat for 2 press [PEEKpressed], bredent), or casting (remanium GM 800+ [CoCrMo], Dentaurum); N = 60, n = 15/subgroup. A total of 50 retention force measurements were performed for each specimen per aging level (initial; after storage [30 days, 37 °C] and 10,000 thermal cycles; after storage [60 days, 37 °C] and 20,000 thermal cycles) in a pull-off test. Data were statistically analyzed using one-way ANOVA, post hoc Scheffé and mixed models (p < 0.05). Results Initial, PEEKpressed (80.2 ± 35.2) and PEEKmilled1 (98.9 ± 40.3) presented the lowest results, while PEEKmilled2 (170.2 ± 51.8) showed the highest values. After artificial aging, the highest retention force was observed for the control group (131.4 ± 56.8). The influence of artificial aging was significantly higher for PEEK-based materials. While PEEKmilled2 and PEEKpressed showed an initial decline in retention force, all other groups presented no impact or an increase in retention force over a repetitive insertion and removal of the clasps. Conclusions Within the tested PEEK materials, PEEKmilled2 presented superior results than PEEKpressed. Although CoCrMo showed higher values after artificial aging, all materials exhibited sufficient retention to recommend usage under clinical conditions. Clinical relevance As RDPs are still employed for a wide range of indications, esthetic alternatives to conventional CoCrMo clasps are sought.

Various invasive and noninvasive methods have been used for measuring primary implant stability. Periotest damping device and resonance frequency analysis with the Osstell device have been classified as noninvasive methods. Primary and secondary implant stability measurements using both devices have given reproducible quantitative values. In this clinical randomized trial, a general correlation was evaluated between the implant stability recorded using both Osstell and Periotest devices on the day of implant installation and 3 months after healing for the submerged and nonsubmerged loading protocols. The present study also investigated whether the difference in gender of the included patients would have an effect on the correlation between the two devices. Eighty completely edentulous patients were recruited, and all patients ranged from 50 to 69 years of age. Overall, 56 men and 24 women were included, with a mean age of 62.5 years for men and 59.6 years for women. A single implant was installed in the midline of the completely edentulous mandible to improve retention of the patient's lower denture. After implant installation, one implant stability quotient (ISQ) value at the buccal surface was recorded, and then the Periotest M device was used to measure the damping effect (Periotest value [PTV]) of the installed implant using the smart peg screwed to the implant. Patients were then randomized into 2 groups using sealed envelopes: the submerged and nonsubmerged groups. For both groups, all ISQ and Periotest readings were recorded in the patient's case report file on the day of implant installation and 3 months after healing. When the ISQ of the buccal surface was correlated to the PTV, there was a moderate negative statistically significant correlation between the 2 readings (correlation coefficient = −.466, P = .000). There tended to be a weak negative correlation between the 2 devices in the male group (correlation coefficient = .395, P = .046) during implant installation, although there tended to be no correlation between the 2 devices in the female group (correlation coefficient = −.367, P = .342). After 3 months of healing, when correlating the readings of the buccal surface of the Osstell with that of the Periotest within each group (submerged and nonsubmerged), there was no statistically significant correlation between the readings within each group (correlation coefficient = −.014, −.430, P = .942, P = .052, respectively). However, there was a strong negative statistically significant correlation between the 2 devices for the female group for both the nonsubmerged group (correlation coefficient = −.823, P = .003) and submerged group (correlation coefficient = −.857, P = .014), whereas there was no statistically significant correlation within the male group for both the nonsubmerged group (correlation coefficient = −.377, P = .123) and submerged group (correlation coefficient = −.022, P = .940). The correlation between the Osstel and Periotest device remains controversial. The present study concluded that there is a significant negative correlation between the 2 devices when recording primary implant stability, although this significance is lost after 3 months of loading when recording secondary implant stability. Gender also affects the implant stability recording, which is mainly due to the difference in bone density between men and women.

Objectives Conventional dental implants inserted in the molar region of the maxilla will reach into the sinus maxillaris when alveolar ridge height is limited. When surgery is performed without prior augmentation of the sinus floor, primary stability of the implant is important for successful osseointegration. This study aimed at identifying the impact of bone quality and quantity at the implantation site on primary implant stability of a simulated bicortical placement. Materials and methods In our in vitro measurements, bone mineral density, total bone thickness and overall cortical bone thickness were assessed by micro-computed tomography (μCT) of pig scapulae, which resembled well the bicortical situation found in human patients. Dental implants were inserted, and micromotion between bone and implant was measured while loading the implant with an axial torque. Results The main findings were that primary implant stability did not depend on total bone thickness but tended to increase with either increasing bone mineral density or overall cortical bone thickness. Clinical relevance Limited bone height in the maxilla is a major problem when planning dental implants. To overcome this problem, several approaches, e.g. external or internal sinus floor elevation, have been established. When planning the insertion of a dental implant an important aspect is the primary stability which can be expected. With other factors, the dimensions of the cortical bone might be relevant in this context. It would, therefore, be helpful to define the minimum thickness of cortical bone required to achieve sufficient primary stability, thus avoiding additional surgical intervention.

Purpose This study compared piezoelectric (PE) and conventional drills (CD) for maxillary aesthetic zone implant insertion. Material and methods This was a prospective split-mouth study. Implants were divided into two groups. Beds were prepared with CDs in group I and PE in group II. The implant stability quotient (ISQ) of the mechanical implant stability (MIS) was measured intraoperatively. The ISQ of the biological implant stability (BIS) was recorded at postoperative second and fourth months. Marginal bone loss (MBL) and bone density (BMD) were measured in the first and second years after prosthetic loading. The osteotomy time was also documented for both techniques. P values Results Sixty implants in 30 patients were included. PE provided a significantly higher ISQ. All values were above 70 throughout the follow-up period. The mean of the ISQ for MIS was 63.78 ± 1.03 and 73.89 ± 1.05 in group I and group II, respectively (p = 0.003). PE needed significantly longer osteotomy time with a mean of 11.99 ± 0.839 min. The BIS quality had high stability in group II and medium stability in group I throughout the study period. Its values decreased in both groups. Group II had a lesser percentage of decrease. However, it was significant only at time intervals between intraoperative and two months' postoperative (p = 0.004). MBL and BMD demonstrated insignificant results. Conclusion The implant site preparation with PE devices should be preferred to CDs whenever possible, because they seem to enhance implant stability and osseointegration, especially at the initial stages of healing.

Purpose This is a single center, retrospective study to assess the prevalence of peri-implant disease and biologic complications in a cohort of partially edentulous subjects in relation to selected prosthetic factors. Materials and methods Subjects previously treated with one or more implant-supported fixed dental prosthesis (ISFDPs) were recalled for a comprehensive examination. Clinical and radiographic records were taken and questionnaires were administered. The prevalence of implant failure, peri-implant disease and other biologic complications were correlated with selected prosthetic, clinical and patient-related factors using chi-square and multiple regression analyses. Results A convenience sample of 71 subjects with 100 prostheses supported by 222 dental implants were enrolled in the study. The mean follow-up time after prosthesis delivery was 3.3 ± 1.5 years (range of 1-9 years). The cumulative implant survival rate was 99.1%. Peri-implantitis was the most frequent major biologic complication (5% of implants), while the most frequent minor biologic complication was peri-implant mucositis (84.10% of implants). A diagnosis of peri-implant mucositis was more likely associated with cement-retained prostheses compared to screw-retained prostheses (OR 6.8, 95% CI 1.1-78.6, p = 0.045) and for short-span prostheses (≤3 prosthetic units) (OR 2.3, 95% CI 1.1-5.0, p = 0.034). Subject-reported quality of life measures were high regardless of the existence of major and/or minor complications, but decreased with increasing number of minor and total biologic complications. Conclusions Peri-implant mucositis and other minor biologic complications were highly prevalent. The distribution of the observed complications differed based on the method of prosthesis retention and the number of prosthetic units replaced.

Purpose To evaluate the amount of residual cement (ECL) around the margins of zirconia crown copings after careful luting and cleaning procedures and to investigate these factors in relation to two tested luting materials. Materials and methods An experimental model of a maxillary arch was selected for this in vitro study. The maxillary first molar was prepared to receive an all-ceramic, single, full-crown restoration with a finish line located 1 mm below the artificial gingiva. After scanning of the prepared tooth, 20 paired zirconia coping-abutment assemblies were CAD/CAM fabricated. A slot in the model allowed for insertion and removal of the assemblies for each new test. Specimens were divided into two groups according to the cementation procedure: half (n = 10) were luted using a resin-modified glass-ionomer (RMGI) (Ketac-Cem Plus) (GI group), and the other half with a dual-curing self-adhesive resin agent (RelyX Unicem 2) (UN group). The substructures were loaded with cement, and a customized preseating device was adopted for preliminary reduction of excess. The zirconia copings were finally seated on their respective abutments located on the simulation model. A blinded investigator attempted to remove all excess cement with clinically available instruments. The amount of excess cement left in situ after cleaning procedures was weighed in grams. Dislodging forces of luted coping-abutment assemblies were obtained by using pull-off tests in a universal testing machine (crosshead speed of 0.5 mm/minute) after 24 hours of water storage. Means and standard deviations were calculated for ECL and for retention force values, and Mann-Whitney and ANOVA tests were carried out to detect significant differences (α = .05) among groups. Results Cement remnants were found in all specimens despite the cleaning procedures, with a typical distribution in interproximal areas. Mean ECL values for the GI and UN groups were 0.0079 ± 0.0060 and 0.0107 ± 0.0081, respectively. No statistically significant differences were found between tested cements (P = .3284). Removal stress values (MPa) were significantly higher (P = .0313) for the UN group (12.4 ± 6.5) than for the GI group (6.57 ± 4.69). Conclusion Similar amounts of undetected cement remnants were discovered around the esthetic margins of zirconia crown copings regardless of cement type. The luting procedure using the self-adhesive resin cement provided significantly higher early retention values than the RMGI material.

While industry best practices exist for sizing and positioning dental implants, too few guidelines are designed to aide clinicians in predicting primary implant stability in healed or fresh extract...

Background: Stainless steel crowns (SSCs) are unique coronal restorative materials used commonly in the management of primary teeth with extensive caries. Aim: The aim of this study was to perform a systematic review to evaluate the retentive strength of luting cements for SSCs. Materials and Methods: Two reviewers performed a database search of the studies published from 2004 till date. The inclusion criteria were papers published in the English language andin vitro studies on retentive strength of SSC on primary molars. All potentially relevant studies were identified by the title and the abstract. After the full-text analysis, the selected studies were included in the systematic review. Results: Sixteen nonduplicated studies were found. However, after reviewing the articles, only seven were included. Risk bias was assessed. Out of seven studies included in the systematic review, five studies presented medium risk of bias and two studies showed high risk of bias. Conclusion: Within the limitations of this study, thein vitro literature seems to suggest that the use of self-adhesive resin cements shows higher retentive strength, followed by resin-modified glass-ionomer cement (RM-GIC) and conventional GIC. However, RM-GIC can be a preferred luting agent due to its clinical advantages over resin cements. Thus, it can be concluded that choice of cement will depend on individual patient needs and clinical situation.

PURPOSE Despite the high success rate of implant-supported fixed restorations in dentistry, there is a lack of evidence on the marginal seal for dental cement. Thus, this study aimed to evaluate the marginal seal of implant-supported crowns and partial dentures cemented using four different dental cements. MATERIALS AND METHODS The study evaluated the marginal seal of implant-supported crowns and partial dentures cemented using zinc phosphate, resin-modified glass-ionomer, self-adhesive resin, and noneugenol, acrylic-urethane polymer-based temporary dental cements. After cementation and thermal cycling procedures, the samples were incubated in Escherichia coli suspension for 5 days at 37°C under an aerobic environment. After debonding the restorations under sterile conditions, sterile cotton swabs were used to obtain microbial samples from the inner surface of each restoration and abutment surface. To analyze the contamination, each sample was immersed in a brain-heart infusion culture medium and incubated at 37°C for 24 hours, and then, the colony-forming units were counted and recorded. RESULTS Regarding the number of colonies for Escherichia coli, the results revealed no substantial difference between the crowns and the fixed partial restorations (P = .25). However, the differences in the level of contamination between the cement groups were significant (P ≤ .001). The self-adhesive resin cement samples showed the lowest level of contamination, followed by the zinc phosphate and resin-modified glass-ionomer cements. The difference in the level of contamination between these groups was not significant. The temporary cement group exhibited significantly higher numbers of bacterial colonies in comparison to the other cement groups. CONCLUSION Self-adhesive resin cement has better biologic properties for retaining implant-supported restorations than other types of dental cement.

Objective: To determine the retentive force of three glass-ionomer luting cements used with prefabricated primary zirconium crowns (PPZCs) and to assess whether the retentive force was dependent on cementation material or different PPZCs brands. Study design: Four mandibular right second molar PPZCs were selected, one each from four manufacturers–NuSmile®ZR, Sprig Crowns, Cheng Crowns and Kinder Krowns. Silicone impressions of the outer surface of crowns were taken; stone dies prepared and reduced to fit the corresponding brand. 24 alginate impressions of each die obtained and filled with core buildup flowable composite. 96 composite tooth-replicas thus achieved were divided into four groups and further categorized into three subgroups of eight samples based on luting cements used – BioCem, FujiCEM®2 and KetacCem. Samples were thermocycled, placed in artificial saliva for one week followed by assessment of retentive force for crown dislodgment and failure mode. Results: Data was statistically evaluated using two-way ANOVA, HSD (P

Purpose This study assessed the survival and marginal bone loss of single-unit short implants (≤ 8 mm in length) in the premolar-molar area. It also compared cemented with screw-retained restoration. Materials and methods In this clinical retrospective study, short implants supporting a single crown in the premolar-molar region were selected. Demographic-, surgical-, implant-, and prosthesis-related data were obtained. The predictor variable was the type of prosthesis retention. The principal variables were survival rate and marginal bone loss. The secondary variables were prosthesis survival and technical and biologic complications. Results A total of 113 patients (56 ± 11 years of age) with 128 short implants were assessed. The mean follow-up time from implant insertion was 25.47 ± 14.95 months. Fifty-one crowns were cemented and 77 were screw-retained. No failure events were recorded for the implants and the prostheses. The distal marginal bone loss was significantly lower in the screw-retained crowns than in the cemented crowns. Marginal bone loss ≥ 2 mm as a biologic complication was more frequent in the cemented crowns. Two screw-loosening events were observed in the screw-retained restorations. These events were resolved by screw retightening. Conclusion Short implants could be an effective option to support a single-unit prosthesis in the premolar-molar areas of the maxillae.

BACKGROUND The implant design and the surgical technique are important parameters that can be modified to improve the implant primary stability. The aim of this study was to evaluate the role of the apical part of an implant on the implant stability of implants placed in Type II dense bone by novice and experienced clinicians. METHODS Implants with a progressive thread design (3.5 mm diameter, 11 mm length) were used. A total of 80 osteotomies were prepared in dense bone samples (quality Type II) by two clinicians with different levels of experience (novice and experienced) under the same surgical protocol. Two experimental groups were prepared. In the test group (apical stability), 40 implants were inserted with only 3 mm of the apical portion of the implant within the bone and without lateral contact between the residual implant length and the osteotomy walls. In the control group (full implant stability), 40 implants were inserted with full contact between the osteotomy walls and the implant surface. The stability of both groups (test and control) was evaluated using a resonance frequency analysis (RFA) (implant stability quotient [ISQ] values). Statistical comparisons between the groups were performed using the Kruskal-Wallis test with Dunn post-test for multiple comparisons. RESULTS The results did not show statistically significant differences (P > 0.05) in terms of primary stability between implants placed by novice or experienced clinicians in dense bone. The control group showed significantly higher ISQ values compared with the test group (P < 0.001). The apical implant stability contributed to ≈ 30% and 43% of the entire implant stability for novice and experienced clinicians, respectively. CONCLUSIONS The apical portion of an implant plays a fundamental role in the entire implant stability and is independent on the clinician's experience. However, precise implant site preparation to guarantee apical implant anchorage is recommended.

The design of an implant has a great effect on primary stability. The purpose of this study was to determine the differences in primary stability between straight and tapered Neoss ProActive implants in type I and type III bones using resonance frequency analysis (RFA) and electronic percussive testing (EPT) methods. Fresh cow vertebrae and pelvis were used as models of type III and type i bone, respectively. Implants of 2 different designs—straight and tapered Neoss ProActive implants with a thread cutting and forming (TCF) design, both 3.5-mm wide and 11-mm long—were placed in both types of bone (n = 60). The primary stability of all implants was measured by an experienced clinician blinded to the study protocol using the EPT and RFA devices. No statistically significant difference was found between the implant stability quotients and the percussive test values of straight and tapered implants in either bone type. Within the limitations of this ex vivo study, it may be concluded that the shape of an implant with a TCF design does not affect primary stability.

Purpose To investigate the implant stability quotient (ISQ) values of implants placed in bone with and without dehiscence bone defects over 12 weeks and to compare the ISQ values between the two groups. Materials and methods Twenty-two patients with edentulous area at posterior mandible were enrolled. Thirty OsseoSpeed EV Astra Tech implants (Dentsply Sirona), 4.2 mm in diameter, were placed. Twenty implants were placed without bone regeneration (control group), while 10 presented with favorable bone defects and received simultaneous guided bone regeneration with dental implant placement (study group). At the time of implant placement, 2, 4, 8, and 12 weeks, resonance frequency analysis (RFA) was utilized. The changes in ISQ values within group were analyzed with repeated-measures ANOVA, and the mean ISQ values between the control and study groups were compared using unpaired t tests. Results All implants were successfully integrated without complication. The control group demonstrated mean ISQ values of 74.30 ± 6.01, 69.58 ± 5.30, 71.10 ± 5.80, 75.08 ± 3.93, and 77.85 ± 3.18 at baseline, 2, 4, 8, and 12 weeks, respectively. The study group demonstrated mean ISQ values of 69.85 ± 7.00, 63.40 ± 8.47, 59.90 ± 10.23, 72.55 ± 3.10, and 76.20 ± 2.68 at baseline, 2, 4, 8, and 12 weeks, respectively. The study group showed significantly lower mean ISQ values at 2 weeks (P = .021) and at 4 weeks (P = .007) after implant placement compared to those of the control group. Conclusion Within the 12-week healing period, all implants demonstrated successful osseointegration and achieved stability in favorable bone defects. Nevertheless, clinicians should consider that significantly lower implant stability can occur in the first month.

Purpose To evaluate the early performance of computer-aided design/computer-aided manufacturing (CAD/CAM)-produced composite resin crown (CAD/CAM composite crown) treatment on premolars, specifically, placement on a removable partial denture (RPD) abutment tooth, and the distalmost tooth in the dental arch, as possible clinical risk factors. Methods A retrospective cohort study (April 2014 to July 2017) was performed utilizing the clinical records of patients who received a premolar CAD/CAM composite crown treatment. The variables of time of treatment for (1) successful crowns (complication event-free) and (2) surviving crowns (clinically functional including re-luted) were estimated using Kaplan–Meier analysis. Survival distributions regarding “RPD abutment tooth” and “distalmost tooth” were analyzed with the log-rank test. Multilevel survival analyses were used to identify hazard ratios and associated risk factors. Results Five hundred and forty-seven crowns were evaluated (mean follow-up time 1.3 ± 0.9 years) in 327 patients. A total of 87 crowns had at least one complication, with loss of crown retention being the most common (70 crowns). Estimated success and survival rates at 3 years were 71.7% and 96.4%, respectively. The risk of complications was significantly higher for an RPD abutment tooth than for a non-RPD abutment tooth. There was no significant difference between the distalmost tooth and non-distalmost tooth in the dental arch. Conclusions The demonstrated complication rate for CAD/CAM composite crowns placed on premolars was 15.9% over a period of up to 3 years. There was a substantial risk of complications with placement of such a crown on an RPD abutment tooth.

Made available in DSpace on 2018-12-11T17:21:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Statement of problem: The decision to splint or to restore independently generally occurs during the planning stage, when the advantages and disadvantages of each clinical situation are considered based on the proposed treatment. However, clinical evidence to help clinicians make this decision is lacking. Purpose: The purpose of this systematic review and meta-analysis was to assess the marginal bone loss, implant survival rate, and prosthetic complications of splinted and nonsplinted implant restorations. Material and methods: This study was designed according to the Cochrane criteria for elaborating a systematic review and meta-analysis and adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Also, this review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42017080162). An electronic search in the PubMed/MEDLINE, Cochrane Library, and Scopus databases was conducted up to November 2017. A specific clinical question was structured according to the population, intervention, comparison, outcome (PICO) approach. The addressed focused question was “Should the restoration of adjacent implants be splinted or nonsplinted?” The meta-analysis was based on the Mantel-Haenszel and inverse variance methods to assess the marginal bone loss, implant survival, and prosthetic complications of splinted and nonsplinted implant restorations. Results: Nineteen studies were selected for qualitative and quantitative analyses. A total of 4215 implants were placed in 2185 patients (splinted, 2768; nonsplinted, 1447); the mean follow-up was 87.8 months (range=12-264 months). Quantitative analysis found no significant differences between splinted and nonsplinted restorations for marginal bone loss. The assessed studies reported that 75 implants failed (3.4%), of which 24 were splinted (99.1% of survival rate) and 51 were nonsplinted (96.5% of survival rate). Quantitative analysis of all studies showed statistically significant higher survival rates for splinted restorations than for nonsplinted restorations. Ceramic chipping, screw loosening, abutment screw breakage, and soft tissue inflammation were reported in the selected studies. The quantitative analysis found no statistically significant difference in the prosthetic complications of splinted and nonsplinted restorations. Conclusions: Within the limitations of this systematic review and meta-analysis, it was concluded that there was no difference in the marginal bone loss and prosthetic complications of splinted and nonsplinted implant restorations; this is especially true for restorations in the posterior region. However, splinted restorations were associated with decreased implant failure. Associate Professor Department of Prosthodontics Presidente Prudente Dental School University of Western São Paulo (UNOESTE) Adjunct Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Doctoral student Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Graduate student Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Full Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School (UNESP) Universidade Estadual Paulista Adjunct Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Doctoral student Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Graduate student Department of Dental Materials and Prosthodontics Araçatuba Dental School São Paulo State University (UNESP) Full Professor Department of Dental Materials and Prosthodontics Araçatuba Dental School (UNESP) Universidade Estadual Paulista

The implant macrogeometry and thread profile represent one of the most important factors for a successful achievement of primary stability during the positioning procedure. The aim of the present investigation was to evaluate the insertion torque (IT), removal torque (RT) and Implant stability Quotient (ISQ) of two different implant macrogeometry and thread profile on solid rigid polyurethane model. Two different implants macrogeometries were tested: K2 (Group I) with 11° angle, 1.17 mm pitch and self-cutting V thread profile and K3 (Group II) implants with 30° angle, 0.71 mm pitch and spyral thread profile. A total of 120 specimens (

This study aimed to assess the effect of cement type and cementation technique on the retention of cement-retained implant-supported restorations.In this in vitro study, 20 solid abutments were screwed onto the fixture analogs and were mounted in acrylic resin molds using a surveyor. Twenty computer-aided design/computer-aided manufacturing (CAD/CAM) metal crowns with an occlusal loop were fabricated, divided into two groups (n = 10), and bonded with temporary dental cement (Temp-Bond™; group 1) or glass ionomer (GC; group 2). Each group was subcategorized based on its cementation method (half-filling or abutment replica technique). The cement was applied to the copings that were placed vertically on the abutment with applying a 5-kg load for 10 min. The samples were then incubated at 37°C for 24 h and subjected to 3000 thermal cycles. The samples underwent axial tensile load within a universal testing machine. Data were analyzed using two-way ANOVA.GC cement yielded significantly higher retention than Temp-Bond™ (P0.05). In the GC group, the half-filling subgroup showed significantly higher retention than the abutment replica subgroup (P0.05). The mean retention value in the Temp-Bond™ group revealed no significant difference between the two subgroups (P0.05). GC yielded higher retention than Temp-Bond™ while using the half-filling cementation technique (P = 0.00). However, this difference was not significant between GC and Temp-Bond™ with the abutment replica technique (P = 0.960).Within the limitations of this study, the results showed that permanent cementation with half-filling technique yielded significantly higher retention in implant restorations.

Introduction: There is no consensus as to which cemented or screwed retention system is best to avoid bone loss around the implant from a fixed implant-supported restoration. Objective: To evaluate the prosthesis retention systems on screw and cemented implants, regarding: bone loss, survival and failure rate, biological complications and microbiological analysis. Methods: A search was made for scientific articles that contemplated the subject through the databases Pubmed and SciELO, without period restriction. The titles, abstracts and then access to the full text has been verified. Results: It was found that excess cement may play an important role in the development of peri-implant disease. Technical failures are most seen in prosthesis retained by screws, and biological complications in cemented crowns. The success rate for both restraint systems is high, and retention-independent implant prosthesis treatment provides predictability. Conclusion: The appropriate retention system for the patient depends on several factors, including indication, advantages and disadvantages, retention provided, aesthetics and clinical performance. RESUMO Introdução: Não há consenso sobre qual sistema de retenção, cimentado ou parafusado, é o melhor para evitar perda óssea ao redor do implante de uma restauração fixa implanto-suportada. Objetivo: Avaliar os sistemas de retenção de próteses sobre implantes parafusadas e cimentadas, quanto aos fatores: perda óssea, taxa de sobrevivência e de falhas, complicações biológicas e análises microbiológicas. Métodos: Foi realizada uma busca por artigos científicos que contemplassem o tema através das bases de dados Pubmed e SciELO, sem restrição de período. Os títulos, resumos e em seguida o acesso ao texto completo foi verificado. Resultados: Foi observado que o excesso de cimento pode desempenhar um papel importante no desenvolvimento da doença peri-implantar. Falhas técnicas são mais observadas em próteses retidas por parafusos e complicações biológicas em coroas cimentadas. A taxa de sucesso para os dois sistemas de retenção é alta e o tratamento com próteses sobre implantes independente da retenção oferece previsibilidade ao caso. Conclusão: O sistema de retenção apropriado para o paciente depende de diversos fatores, incluindo a indicação, vantagens e desvantagens, retenção fornecida, estética e desempenho clínico.

Objectives: Implant-supported restorations are generally used for the replacement of the lost teeth. Stability against masticatory forces and proper retention are critical for optimal durability of restorations. The aim of this experimental study was to compare the retention of cobalt-chromium (Co-Cr) copings made by different techniques. Materials and Methods: Twenty-four solid abutment analogs were mounted and scanned with a desktop scanner. They were divided into two groups (n=12) and received metal copings fabricated by either soft or hard Co-Cr alloy. Soft Cera­mill Sintron Co-Cr patterns were milled and sintered. Hard Co-Cr blocks were milled in a milling machine. The copings were sandblasted, polished, adjusted, and placed on the respective abutments. The frequency of adjustments was recorded for each abutment. The copings were cemented with zinc phosphate cement and underwent tensile test by a universal testing machine. The Mann-Whitney test and t-test were used to compare the two groups (α=0.05). Results: There was no significant difference in retention of copings between the experimental groups. The mean retentive force was 559.58±115.66 N and 557.13 ±130.48 N for the soft and hard metal groups, respectively (P=0.96). Considering the non-normal distribution of adjustment frequency data, the Mann-Whitney test showed that the frequency of adjustments was significantly higher in the hard metal group than the soft metal group (9.5 versus 0.1667; P

Purpose To determine the prevalence and distribution of prosthetic complications affecting implant-supported fixed dental prostheses (ISFDPs). Materials and methods Subjects previously treated with one or more ISFDP(s) were identified from an electronic health record search and recalled for comprehensive clinical examination. Past prosthesis failures and complications were identified from the patient records while any existing complications, not previously recorded, were assessed during examination. ISFDP survival and failure rates were calculated with Kaplan-Meier curves and life table analysis, while regression Poisson analysis was used to identify associations between outcomes and possible patient- and prosthesis-based risk factors. Results Seventy-four subjects with 107 ISFDPs were enrolled in the study with a mean time between prosthesis delivery and exam of 3.14 years (range: 1.00-9.00 years). Four prostheses failed, resulting in a cumulative prosthesis survival rate of 96.26%. Prosthetic complications affected 48.59% of ISFDPs, the majority (94.87%) of them minor complications. Only the use of a nightguard was associated with a lower prevalence of prosthetic screw loosening (HR 0.11, 95% CI 0.02-0.59, p = 0.007) while no outcome differences were noted for other variables. Patient satisfaction was high regardless of presence or number of complications. Conclusions ISFDPs demonstrated a high survival rate and overall high, patient-reported satisfaction. Minor prosthetic complications were common but were only significantly associated with nightguard use.

Background and objectives: To compare the medium- to long-term mechanical behavior of overdentures with two different retention systems: overdentures with Locator&reg, axial retention, and vertical insertion overdentures with bar retention, used to rehabilitate edentulous maxillar. Material and Methods: This prospective study assessed patients presenting complete maxillary edentulism, rehabilitated by means of implant-supported overdentures (n = 20), 10 with Locator&reg, axial retention (ODA group) and 10 with overdentures on bars (ODB group). Patients also completed a questionnaire to determine their satisfaction with treatment. Results: The mean follow-up time in both groups was 11.4 years, with follow-up times in both groups ranging from 5 to 14 years. The ODA group suffered mechanical complications such as retention loss, need for nylon retention insert changes, resin fracture, and need for relining. In the ODB group, prosthetic dental wear, screw loosening, and complete prosthetic failure were more common. A total of 19 implants failed (23.8%), of these, 11 were in the ODA group (failure rate = 27.5%) and eight in the ODB group (failure rate = 20%). The patient satisfaction questionnaire obtained a mean score of 7.9 out of 10 in the ODA group, and 9.75 in the ODB group. Conclusions: in rehabilitations of edentulous maxillar by means of implant-supported overdentures, both the systems assessed were shown to be effective in the medium to long term. Patients expressed a high level of satisfaction with the treatments received.

Background The aims of this study were to enumerate the primary implant stability quotient (ISQ) value of self-tapping dual etched implants and to explore the influence of parameters such as implant length, implant diameter, age, gender, implant location and osteotomy preparation on the ISQ value. Methods Retrospective data from clinical worksheets given to participants during two implant courses held between the periods of 2013 to 2014 were evaluated. A total of 61 implants were considered based on the inclusion criteria. The effects of parameters such as implant diameter, implant length, age, gender, implant location and osteotomy protocol on ISQ values were analyzed. Results Mean ISQ value for all implants was 67.21±9.13. Age of patients (P=0.016) and location of implants (P=0.041) had a significant linear relationship with the ISQ values. Within the age limit of the patients in this study, it was found that an increase in one year of patient's age results in 0.20 decrease in ISQ value (95% CI: -0.36, -0.04). However, placing an implant in the posterior maxilla may negatively affect the ISQ with a likely decrease in primary stability by 6.76 ISQ value (95% CI: -13.22, -0.30). Conclusions The results suggest that the mean ISQ achieved by the participants were comparable with the range reported for this particular type of implants. The patient's age and location of implants were elucidated as the determinant factors of primary implant stability.

Objectives We performed a randomized clinical study evaluating the stability of implants with different surfaces (alkali-modified or sandblasted) via resonance frequency analysis (RFA). Materials and Methods Fourteen patients who were bilaterally edentulous in terms of their mandibular molars were enrolled. Implants with alkali-modified (bioactive) and sandblasted surfaces were randomly placed in either hemi-arch; the 50 implants used were identical in terms of diameter and length. RFA was used to measure the implant stability quotient (ISQ) immediately after placement (to assess primary stability) and 2, 6, and 12 weeks later. Results The average RFA value for alkali-modified implants was significantly higher than that for sandblasted implants immediately after implantation, but the ISQs fell rapidly and were similar in the two groups at 2 and 6 weeks (p > .05); ISQ values were the same in the two groups at 3 months (p > .05). Conclusions Implants with alkali-modified surfaces were more stable than implants with sandblasted surfaces at all times after placement. The ISQs of bioactive implants exhibiting high-level primary stability fell to greater extents than did those of implants with sandblasted surfaces at 2 and 6 weeks postoperatively; both types of implant yielded similar clinical results at 12 weeks postoperatively. Selcuk University

Full-arch, fixed, implant-supported prostheses can be designed to be cement- or screw-retained. Both retention mechanisms have a few inherent disadvantages. A fixed attachment system has been introduced to circumvent the disadvantages of both screw and cement retention. This system eliminates the screw access holes and the use of cement. The number of intraoral procedures required is also reduced. The purpose of this article is to report a case using the Locator F-Tx Attachment System to facilitate fabrication of an esthetic, clinician-retrievable, full-arch implant-supported fixed dental prosthesis.

Introduction: Osseointegration as formulated by Alberktson is crucial for implant survival and success. Osseointegration is a measure of implant stability. Measuring implant stability helps to arrive at decisions as to loading of an implant, allows protocol choice on a patient to patient basis and provides enhanced case documentation. The RFA technique provides with clinically relevant information about the state of the implant–bone interface at any stage after implant placement. Aim: Evaluation of primary and secondary stability between implants of two different systems by resonance frequency analysis device. Methodology: This study was conducted among 17 patients divided into two groups. Group 1 (n = 10) receiving 20 MIS seven implants and Group 2 (n = 7) received 20 Alphadent active implants. The primary implant stability was measured at the time of implant placement and secondary stability is measured at 3–4 months interval using RFA device OSSTELL ISQ. Statistical analysis was performed using paired t test for intra group and independent sample test for intergroup comparisons. Results: No statistically significant differences in primary and secondary stabilities were found between the implant systems at either time intervals (P > 0.05). A positive correlation was noticed between mesiodistal stability and implant diameter in MIS seven group (P < 0.05). A positive correlation was noticed between mesiodistal, labiolingual stabilities and implant diameter in Alphadent group (P = 0.03). A positive correlation was noticed between mesiodistal, labiolingual stabilities and implant length in Alphadent group (P = 0.03). Conclusion: From the present data, it can be concluded that within the limitations of study, implant systems used and their design features showed no significant correlation to implant stability between the groups. More studies are required to assess the effect of implant designs and surface conditions on implant stability on a long-term basis.

The aim of the present study was a systematic review and subsequent meta-analysis on biological complications of removable prostheses in the moderately reduced dentition. A systematic literature search in established medical databases (MEDLINE, EMBASE, BIOSIS, SciSearch, Cochrane, FIZ Technik Web) and a hand search of relevant dental journals was conducted. The search terms were relevant MeSH terms, free search terms, and combinations of the two. The search included randomized controlled trials, prospective and retrospective studies with data on biological complications of removable dental prostheses in the moderately reduced dentition with at least 15 participants, an observation period of at least 2 years, and a drop-out rate of less than 25%. The selection of relevant publications was carried out at the title, abstract, and full-text level by at least two of the authors involved. The publications included were tabulated and analyzed. Of the original 12,994 matches, 1923 were analyzed by title, 650 by abstract, and 111 according to the full text. A total of 42 publications were ultimately included. The following parameters were evaluated. Results varied, depending on the observation period, between 0 and 18.1% for clasp-retained removable dental prostheses (RDPs), between 5.5 and 29% for attachment-retained RDPs, and between 5.5 and 51.7% for double crown-retained RDPs. Results varied, depending on the observation period, between 0 and 32.7% for clasp-retained RDPs, between 1.8 and 29% for attachment-retained RDPs, and between 1.8 and 16.4% for double crown-retained RDPs. Results varied, depending on the observation period, between 3.5 and 19.2% for clasp-retained RDPs, between 6.9 and 16.4% for attachment-retained RDPs, and between 0.6 and 13.9% for double crown-retained RDPs. Results varied, depending on the observation period, between 1.7 and 5.3% for clasp-retained RDPs, between 12.7 and 40% for attachment-retained RDPs, and between 0.4 and 4.4% for double crown-retained RDPs. There were no changes or improvements for clasp-retained RDPs. The better the pre-treatment and supportive care is, the smaller the differences are. For double crown-retained RDPs, a slight increase was found in one study. The results for the parameters probing depth and radiological bone loss were inconclusive. Gingival recession seemed to be favored by a mandibular sublingual bar. Compared to fixed restorations, removable restorations seemed to be associated with a more pronounced need for dental treatment. Stringent pre-treatment and supportive care reduced the complication rates. Heterogeneous study designs and data analyses rendered a meta-analysis impossible, so that an evaluation at the highest level of evidence could not be performed. Within the limitations of this study, it would be correct to state that removable dental prostheses require intensive maintenance. Suitable pre-treatment and supportive care can lower the complication rates, in the absence of which they constitute trigger factors for (additional) biological complications.

This randomized split-mouth clinical trial investigated the influence of implant macrogeometry on bone properties and peri-implant health parameters during the healing process. Ninety-nine implants were placed bilaterally in posterior mandibles of 23 patients that received at least four dental implant macrogeometries: standard geometry, Integra (IN) and three geometries inducing “healing chamber”: Duo (D), Compact (C), and Infra (IF). Insertion torque (IT) and implant stability quotient (ISQ) were measured. Peri-implant health were monitored by visible plaque index (VPI), peri-implant inflammation (PI), and presence of calculus (CC). Data were collected during 90 days. Data were assessed for normality using the asymmetry and kurtosis coefficients followed by the Shapiro-Wilk test. A one-way ANOVA was used to investigate differences in IT and linear bone dimensions between the macrogeometry groups. The repeated measurements ANOVA test or ANOVA-R was used for analysis of ISQ, VPI, and PI. Tukey-Kramer test or Student’s t test was used for comparisons between the groups or within each macrogeometry. Macrogeometry did not significantly influence IT and ISQ values. The minimum ISQ was recorded after 7 days (71.95 ± 12.04, p = 0.0001). Intermediate ISQ was found after 14 days, when the ISQ reached values that are statistically identical to primary stability. The VPI showed significantly higher scores for the D (0.88 ± 1.03) and IN (0.72 ± 0.94) implants after 7 days. The PI was only influenced by the healing time significantly decreasing from 7 (1.07 ± 0.89) to 21 days (0.18 ± 0.18). Implant macrogeometry did not influence IT nor ISQ values. The relationship between IT and SS was more evident for the Duo implant, but only in the final stage of healing process. Show to the clinician that the macrogeometry and drilling protocols did not interfere in the clinical behavior of the implants during the healing process. However, the IT, primary and secondary stability, is quite dependent of the surgeon experience.

SUMMARY The absolute marginal gap (AMG) precementation and postcementation and the retention of zirconia crowns cemented to standardized molar preparations (4×10) by self-adhesive resin cements (SARCs) were evaluated. The following SARCs were used: RelyX U-200 (RXU200; 3M ESPE, Seefeld, Germany), SmartCem 2 (SC2; Dentsply, Milford, DE, USA), and G-Cem Automix (GCA; GC, Alsip, IL, USA). The control adhesive resin cement was Panavia 21 (PAN; Kuraray Dental Co Ltd, Osaka, Japan). Twenty measuring locations at a constant interval along the margins were marked, and the AMG was measured by an image analysis system connected to a stereomicroscope (20×). The cemented copings were aged 270 days at 100% humidity and 37°C and then underwent 10,000 thermal cycles, 5°C-55°C. After aging, the crowns were tested for retention, and the debonded surfaces were examined at 3× magnification. The mean marginal gaps precementation and postcementation were 34.8 ± 17.4 μm and 72.1 ± 31 μm, respectively, with no statistically significant differences between the cements. A significant difference (p≤0.001) in retention between the cements was found. The highest values were obtained for SC2 and GCA (1385 Pa and 1229 Pa, respectively), but these presented no statistically significant differences. The lowest values were found for PAN and RXU200 (738 Pa and 489 Pa, respectively), but these showed no statistically significant differences. The predominant mode of failure in all of the groups was mixed, and no correlations were found between marginal gap and retention.

Existing root-analog dental implant systems have no standardized protocols regarding retentive design, surface manipulation, or prosthetic attachment design relative to the site's unique anatomy. Historically, existing systems made those design choices arbitrarily. For this report, strategies were developed that deliberately reference the adjacent anatomy, implant and restorable path of draw, and bone density for implant and retentive design. For proof of concept, dentate arches from human cadavers were scanned using cone-beam computed tomography and then digitally modeled. Teeth of interest were virtually extracted and manipulated via computer-aided design to generate root-analog implants from zirconium. We created a stepwise protocol for analyzing and developing the implant sites, implant design and retention, and prosthetic emergence and connection all from the pre-op cone-beam data. Root-analog implants were placed at the time of extraction and examined radiographically and mechanically concerning ideal fit and stability. This study provides proof of concept that retentive root-analog implants can be produced from cone-beam data while improving fit, retention, safety, esthetics, and restorability when compared to the existing protocols. These advancements may provide the critical steps necessary for clinical relevance and success of immediately placed root-analog implants. Additional studies are necessary to validate the model prior to clinical trial.

Acquired defects typically result from traumatic injuries such as falls, motor vehicle accidents, gunshot injuries or radiation injuries. Those maxillofacial defects resulting from motor vehicle accidents in particular often involve various soft and hard-tissue injuries such as fractures or avulsions of the maxillary or mandibular teeth or fractures of the temporomandibular joints. For a patient suffering such injuries, the retention and stabilization of a prosthesis that contributes to the patient's physical and psychological well-being are often difficult to achieve due to the nature of the moveable tissue beds involved and the resulting lack of support from the remaining teeth and bones. This clinical report describes the treatments of two partially edentulous patients with traumatic injuries that resulted from motor vehicle accidents. The prosthetic rehabilitations were accomplished through the manufacture of (1) a mandibular prosthesis with an extracoronal bar attachment, and (2) a maxillary implant-supported removable prosthesis. Sonradan ortaya çıkan maksillofasyal defektler; düşme, motorlu taşıt kazaları, ateşli silah yaralanmaları ya da radyasyon yaralanmaları gibi genellikle travmalardan kaynaklı olurlar. Motorlu taşıt kazaları çeşitli fraktürleri ve avülzüyonları içeren yumuşak ve sert doku kayıplarını içerirler. Bu tür hastalar için fiziksel ve psikolojik iyi hissetmelerini sağlayacak protezlerin retansiyon ve stabilitesini elde etmek, hareketli yumuşak doku alanlarından ve destek diş ile kemik dokusunun azalmasından dolayı çok zordur. Bu klinik raporda, iki travmatik hastanın alternatif tedaviler ile rehabilitasyonu anlatılmaktadır. Vaka 1 için eksternal koronal bar ataçmanlı mandibuler protez, Vaka 2 için maksiller implant destekli hareketli bölümlü protez ile rehabilitasyon yapılmıştır ve bu protezlerin avantajlarından bahsedilmiştir.

Purpose To evaluate the current status of all-ceramic inlay-retained fixed dental prostheses (CIR-FDPs) for the replacement of posterior teeth. Study selection Screening of titles and abstracts, full-text analysis for inclusion eligibility, quality assessment, data extraction and evaluation of the scientific evidence were performed independently by two reviewers. The electronic databases MEDLINE/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Compludoc were searched with no restriction to publication date or language. The quality of the studies was evaluated through: the original ‘QDP' (‘Questionnaire for selecting articles on Dental Prostheses') (for research papers); the ‘Guidelines for managing overviews' of the Evidence-Based Medicine Working Group (for reviews); the Cochrane risk of bias tool; and the GRADE scale for grading scientific evidence. Results This review started with 4942 articles, which were narrowed down to 23 according to the selection criteria. The data was not statistically treated because of the heterogeneity of the studies. Zirconia-based CIR-FDPs may be recommended for restoring posterior single missing teeth, although the prosthesis/tooth bonded interface has yet to be improved. The addition of lateral wings to the classical inlay preparation seems promising. The weakest parts of CIR-FDPs are the connectors and retainers, while caries and endodontic problems are the most common biological complications. The fabrication of CIR-FDPs with monolithic zirconia may eliminate chipping problems. Conclusions A three-unit CIR-FDP is a viable treatment option for replacing a posterior missing tooth. Appropriate case selection, abutment preparation and luting procedures may be decisive for clinical success.

Purpose: This review aimed to compile and enumerate all the factors described in the literature that may affect the decision to use either cemented or screw-retained restorations and to determine the relative weights of each factor by type of retention and prosthesis. Materials and Methods: The literature was reviewed, and the factors were classified as either determining (present in a clinical situation in which one of the retention mechanisms was clearly more suitable than the other) or conditioning (present in clinical situations in which one type of restoration was not clearly more advantageous than the other). Results: Three determining factors (esthetic outcome, retention, and biologic risk) and five conditioning factors (passive fit, fracture strength, occlusal area, complications, and retrievability) were identified. Conclusion: Although there is not a clearly better alternative for all clinical situations, determining factors in certain scenarios can render one of the two approaches more recommendable. For esthetic reasons, when the implant angle cannot be corrected to conceal the access hole, cementation is more suitable; however, screw retention is the better option when the occlusal space is under 6 mm or margins cannot be located supra- or equigingivally. In the absence of determining factors, the decision should be based on conditioning factors, which carry different weights depending on the type of prosthesis. Sin financiación 1.533 JCR (2018) Q3, 47/91 Dentistry, Oral Surgery & Medicine 0.914 SJR (2018) Q1, 657/2894 Medicine (miscellaneous) No data IDR 2018 UEM