Comparative Study of the Influence of Heat Treatment on Fracture Resistance of Different Ceramic Materials Used for CAD/CAM Systems.

The aim of this study was to compare the influence of heat treatment on fracture resistance (FR) of different ceramic materials used for CAD/CAM systems. METHODS: Eighty monolithic restorations were designed using the same parameters and milled with a CAD/CAM system (CEREC SW 5.0, PrimeMill, Dentsply-Sirona™, Bensheim, Germany), forming five study groups: Group 1 (n = 10), CEREC Tessera (Dentsply-Sirona™, Bensheim, Germany) crystallized (CCT), Group 2 (n = 10), CEREC Tessera uncrystallized (UCT), Group 3 (n = 20), Emax-CAD (Ivoclar Vivadent, Schaan, Liechtenstein) (CEC), Group 4 (n = 20), Vita Suprinity (Vita Zahnfabrik, Bad Säckingen, Germany) (CVS), and Group 5 (n = 20) Cameo (Aidite, Qinhuangdao, China) (CC). RESULTS: The average FR was similar for CCT, CC, and CEC at above 400 N, while CVS and UCT had the lowest values at 389,677 N and 343,212 N, respectively. CONCLUSION: Among the three ceramic materials that exhibited an FR above 400 N, CCT was considered the first recommended choice for CAD/CAM systems. This material not only demonstrated the highest FR but also exhibited outstanding consistency in the related measurements without the presence of outliers. Although the CC material showed high FR, its high dispersion revealed inconsistencies in the repetitions, suggesting caution in its use.

Effect of Dentin Irrigants on Push-Out Bond Strength in Resin Cementation Protocols for Fiber Posts in Endodontically Treated Teeth: An In Vitro Study.

The aim of this study is to analyze the effects of different endodontic irrigants and adhesive systems on the resin bond strength of fiber post cementation. In total, 144 single-rooted, unrestored human teeth were endodontically treated and randomly divided into 12 groups according to four endodontic irrigants (distilled water as control; EDTA 17%; NaOCl 5%; chlorhexidine digluconate 2%) and three different adhesive/resin cement systems (etch-and-rinse: orthophosphoric acid, Parabond® A+B/Paracore®; self-etch: ParaBond® Non-Rinse Conditioner, Parabond® A+B/Paracore®; Universal: ClearfilTM Universal Bond/ClearfilTM DC Core Plus). Forty-eight hours after post cementation, ten teeth from each group were cross-sectioned into three discs (cervical, middle and apical regions). Thirty specimens of each group (n = 30) were submitted to a push-out test at a crosshead speed of 1 mm/min. The remaining two teeth of each group were sectioned in the same manner, and the resin-dentin interface was evaluated using scanning electron microscopy (SEM). The results were statistically analyzed with the ANOVA test and Tukey's test (p < 0,01). The adhesive protocols and post space region showed no significant effect on bond strength (p > 0.01). The combination of NaOCl 5% and ClearfilTM Universal Bond reduced the adhesive strength (p < 0.01). The NaOCl 5%, in relation to other irrigants, significantly decreased the push-out bond strength.

Effects of endodontic irrigation solutions on structural, chemical, and mechanical properties of coronal dentin: A scoping review.

OBJECTIVE: This review aims to assess structural, chemical, and mechanical properties of coronal dentin after endodontic irrigation. MATERIALS AND METHODS: Reporting followed the PRISMA extension for scoping reviews. An electronic search was carried out in PubMed, Embase, and Cochrane Library. Records filtered by language and published up to November 4, 2022 were independently screened by two researchers. Studies evaluating structural, chemical, or mechanical properties of human permanent coronal dentin after irrigation within the scope of nonsurgical root canal treatment were included. Data were extracted regarding study type, sample description and size, experimental groups, outcome, evaluation method, and main findings. RESULTS: From the initial 1916 studies, and by adding 2 cross-references, 11 in vitro studies were included. Seven studies provide ultrastructural and/or chemical characterization, and six assessed microhardness and/or flexural strength. One percent to 8% sodium hypochlorite (NaOCl) and 1%-17% ethylenediaminetetraacetic acid (EDTA) were the most commonly tested solutions, with contact times of 2-240 min (NaOCl) and 1-1440 min (EDTA) being evaluated. CONCLUSIONS: Overall, the literature is consensual regarding the inevitable impact of NaOCl and chelating agents on coronal dentin, with both deproteinizing and decalcifying effects being concentration- and time-dependent. The alteration of mechanical parameters further confirmed the surface and subsurface ultrastructural and chemical changes. CLINICAL SIGNIFICANCE: Endodontic treatment success highly depends on restorative sealing. Understanding the result of exposing coronal dentin, the main substrate for bonding, to irrigants' action is crucial. The deproteinizing and decalcifying effects of NaOCl and chelating agents are both concentration- and time-dependent, causing surface and subsurface ultrastructural, chemical, and mechanical alterations.

Particle abrasion as a pre-bonding dentin surface treatment: A scoping review.

OBJECTIVE: This scoping review aims to assess the influence of air abrasion with aluminum oxide and bioactive glass on dentin bond strength. MATERIALS AND METHODS: An electronic search was conducted in three databases (PubMed, Cochrane Library, and Embase), on March 3rd, 2023, with previously identified MeSH Terms. A total of 1023 records were screened. Exclusion criteria include primary teeth, air abrasion of a substrate other than sound dentin, use of particles apart from aluminum oxide or bioactive glass, and studies in which bond strength was not assessed. RESULTS: Out of the 1023 records, title and abstract screening resulted in the exclusion of 895 and 67 studies, respectively, while full-text analysis excluded another 25 articles. In addition, 5 records were not included, as full texts could not be obtained after requesting the authors. Two cross-references were added. Thus, 33 studies were included in this review. It is important to emphasize the absence of standardization of air abrasion parameters. According to 63.6% of the studies, air abrasion does not influence dentin bond strength. Moreover, 30.3% suggest improving bonding performance, and 6.1% advocate a decrease. CONCLUSIONS: Air abrasion with aluminum oxide does not enhance or impair dentin bond strength. The available data on bioactive glass are limited, which hinders conclusive insights. CLINICAL SIGNIFICANCE: Dentin air abrasion is a widely applied technique nowadays, with numerous clinical applications. Despite the widespread adoption of this procedure, its potential impact on bonding performance requires a thorough analysis of the existing literature.

Clinical in-situ evaluation of the effect of rubber dam isolation on bond strength to enamel.

OBJECTIVE: To evaluate the effect of rubber dam isolation on shear bond strength of two different adhesive systems to enamel. MATERIALS AND METHODS: The mesial, distal, lingual, and vestibular enamel surfaces of thirty human third molars were prepared (total n = 120). A custom splint was made to fit a volunteer's maxilla, holding the specimens in place in the oral cavity. Four composite resin cylinders were bonded to each tooth with one of two bonding agents (OptiBond FL and Prime&Bond active) with or without rubber dam isolation. Shear bond strength was tested in a universal testing machine and failure modes were assessed. Significance level for statistical analyses was set at 5%. RESULTS: All pairwise comparisons revealed statistical differences (p < 0.05). The highest mean shear bond strength values were obtained in rubber dam experimental groups, regardless of the adhesive system. Group OptiBond FL with rubber dam presented the highest mean bond strength values. Fracture modes for specimens bonded without rubber dam isolation were adhesive and cohesive within enamel, while rubber dam experimental groups revealed only cohesive fractures. CONCLUSIONS: Absolute isolation with rubber dam increases bond strength to enamel, independent of the adhesive system. The three-step total-etch system OptiBond FL provided significantly higher bond strength values than Prime&Bond active under both experimental conditions. CLINICAL SIGNIFICANCE: Rubber dam isolation has a significant effect on bond strengths to enamel, independent of the adhesive system. Its application is, therefore, advised whenever adhesive procedures are performed. A filled three-step etch-and-rinse adhesive performed superiorly, with or without rubber dam isolation, when bonding to enamel compared to an isopropanol-based universal adhesive.

Long-Term Outcome of Nonvital Immature Permanent Teeth Treated With Apexification and Corono-Radicular Adhesive Restoration: A Case Series.

INTRODUCTION: This study aimed to evaluate the long-term outcome of 16 permanent maxillary central incisors with nonvital pulps and open apices treated with apexification and corono-radicular adhesive restorations, within a follow-up span of 5 to 22 years. METHODS: Fourteen patients providing a total of 16 teeth treated with mineral trioxide aggregate (n = 12), Biodentine (n = 3), or ß-tricalcium phosphate (n = 1) apical barrier and corono-radicular restoration, with or without fiberglass post, were included. Clinical and radiographic criteria were defined for assessment at recall. Restoration and periapical tissue status evaluation were performed according to FDI World Dental Federation's esthetic, functional, and biological criteria and Ørstavik Periapical Index (PAI). Outcome was dichotomized as "healed" (PAI ≤ 2, asymptomatic with absence of signs of infection) or "not healed" (PAI ≥ 3, presence of clinical signs and/or symptoms). RESULTS: Fourteen of 24 patients were available for the present study (recall rate = 58%). Within a follow-up of 5 to 22 years, 10 (62.5%) teeth were considered "healed," fulfilling both strict clinical and radiographic success criteria. Only 1 tooth was missing due to root resorption and 1 patient was presenting with clinical signs and symptoms at recall, resulting in a survival rate of 93.8%. CONCLUSIONS: Adhesive corono-radicular restoration in nonvital permanent immature teeth treated with apexification allows for favorable long-term outcomes, by ensuring structural reinforcement and coronal microleakage prevention. Teeth sustaining a substantial loss of coronal structure may require post/core placement. In the case of failure, this endodontic-restorative combination ensured teeth survival until growth phase conclusion, thus allowing for proper prosthetic rehabilitation approaches.

Fracture Resistance of Sintered Monolithic Zirconia Dioxide in Different Thermal Units.

The purpose of this study was to compare the fracture strength of monolithic zirconium dioxide subjected to a sintering process in two different furnaces: InFire HTC Speed and CEREC SpeedFire. METHODS: Forty restorations were designed and machined using a computer aided design / computer aidded machine (CAD/CAM) system. The restorations were randomly assigned to two groups of 20 samples each, Group 1 for the SpeedFire furnace (fast sintering) and Group 2 for the InFire furnace (slow sintering). Each of the crowns was subjected to a maximum compression load recorded in Newtons (N) and a displacement control with a speed of 1 mm/min. RESULTS: Group 1 presented an average of 1222.8 N and a standard deviation of 136.91 N. Group 2 obtained a mean of 1068.5 N and a standard deviation of 316.39 N. CONCLUSIONS: There were no significant differences between the two groups, and the mechanical strength of the material was not affected, which would imply a saving of clinical and laboratory time when performing rapid sintering on monolithic translucent zirconium dioxide restorations. However, rapidly sintered restorations have limited reliability.

Luting indirect restorations with resin cements versus composite resins: Effects of preheating and ultrasound energy on film thickness.

OBJECTIVE: This study aims to evaluate and compare the film thickness obtained with a resin cement and two composite resins, preheated and/or ultrasonically vibrated, as luting agents. MATERIALS AND METHODS: One hundred and twenty-six (126) pairs of resin discs were randomly assigned to six experimental groups (n = 21) according to luting agent (Variolink Esthetic LC, IPS Empress Direct or Estelite Omega) and cementation technique (preheating at 68°C and/or ultrasonic vibration). Specimens were luted by applying a controlled force. Following sectioning and film thickness measurement through field emission gun scanning electron microscopy, statistical analysis was carried out considering a 5% significance level. RESULTS: Statistically significant lower film thickness was observed in Variolink Esthetic LC group when compared to all composite resin groups (p < 0.001), except IPS Empress Direct preheated and ultrasonically vibrated group (p = 0.073). IPS Empress Direct with ultrasonic vibration yielded statistically lower film thickness values than Estelite Omega groups, regardless of luting technique (p < 0.05). Ultrasonically vibrated Estelite Omega groups showed statistically lower film thickness values than solely preheated groups (p < 0.05). CONCLUSIONS: Both Variolink Esthetic LC and IPS Empress Direct preheated and ultrasonically vibrated provided the lowest film thickness. The addition of ultrasonic vibration during cementation proved to be effective in reducing film thickness of both tested composite resins. CLINICAL SIGNIFICANCE: The cementation technique will have variable results depending on the luting material. Adhesive cementation protocols with composite resins should mainly consider ultrasonic vibration, but also preheating, as strategies for reducing film thickness. The tested resin cement, alongside with IPS Empress Direct composite resin preheated and ultrasonically vibrated, provided the lowest film thickness among the tested materials and techniques.

Evaluation of the Interfaces between Restorative and Regenerative Biomaterials Used in Vital Pulp Therapy.

BACKGROUND: Calcium-silicate-based cements (CSC) have gained an increasing scientific and clinical relevance, enabling more conservative approaches, namely pulp preservation and regeneration therapies. This research aims to study the influence of four clinical variables on the interfaces between CSC and composite adhesive restoration, concerning shear bond strength (SBS) and ultra-morphological patterns. METHODS: SBS tests were performed in 320 specimens divided in 16 groups (n = 20) according to: two CSC (NuSmile® NeoMTA, BiodentineTM); two adhesive systems (ClearfilTM SE Bond 2 (CSEB2), ClearfilTM Universal Bond Quick (CUBQ)); optional application of an additional hydrophobic bonding layer (HBL); two restoration times (immediate, seven days). Scanning electron microscopy (SEM) was performed to conduct the ultra-morphology interface analysis in 32 deciduous molars prepared and randomly allocated into the 16 groups. RESULTS: Globally, SBS tests showed higher bond strength of CUBQ compared to CSEB2 (p < 0.001), as with an additional HBL application (p = 0.014) and delayed restoration (p < 0.001). SEM showed the interpenetration between adhesive systems and CSC forming a hybrid layer, whose depth and thickness depended on the restoration time and adhesive strategy. CONCLUSIONS: The independent clinical variables adhesive system, application of an additional HBL and restoration time affected the bond performance and ultra-morphological interface between composite adhesive restoration and CSC.

Effect of crown-to-implant ratio and crown height space on marginal bone stress: a finite element analysis.

BACKGROUND: Crown-to-implant ratio and crown height space, associated with the use of short implants, have been related with marginal bone loss. However, it is unclear which of the two entities would play the most important role on the bone remodelling process. Using a finite element analysis, the present work aims to help clarifying how those two factors contribute for the stress generation at the marginal bone level. A numerical model (reference model), with a crown-to-implant ratio of 4, was double validated and submitted to a numerical calculation. Then, it was modified in two different ways: (a) by decreasing the prosthetic height obtaining crown-to-implant ratios of 3, 2.5 and 2 and (b) by increasing the implants length obtaining a crown-to-implant ratio of 2.08. The new models were also submitted to numerical calculations. RESULTS: The reference model showed a marginal bone stress of 96.9 MPa. The increase in the implants' length did not show statistically significant differences in the marginal bone stress (p-value = 0.2364). The decrease in the prosthetic height was accompanied with a statistically significant decrease in the marginal bone stresses (p-value = 2.2e- 16). CONCLUSIONS: The results represent a paradigm change as the crown height space appears to be more responsible for marginal bone stress than the high crown-to-implant ratios or the implants' length. New prosthetic designs should be attempted to decrease the stress generated at the marginal bone level.

Microtensile Bond Strength of Three Different Adhesive Systems to Primary Enamel: An In Vitro Study.

Purpose: The purpose of this in vitro study was to assess and compare the microtensile bond strength of three adhesive systems to primary enamel. Methods: This laboratory study involved the preparation of 16 primary molars, randomly distributed over three groups, using the following adhesive systems: GI-Prime&Bond® XP (PBXP); GII-Clearfil™ SE Protect Bond (CSEPB); and GIII-Clearfil™ S3Bond Plus (CSB). After applying each adhesive system on enamel as recommended, Ceram. X™ Universal composite blocks were built. Samples were then cross-sectioned into quadrangular test specimens and subjected to microtensile tests. Fracture patterns were classified by optical microscopy examination. Statistical analysis was performed using IBM SPSS 24.0 software (five percent significance level). Results: PBXP showed statistically higher levels of microtensile adhesion than CSEPB and CSB, which, in turn, did not significantly differ from each other. Fracture patterns observed were, for the majority, adhesive fractures across all groups. There was no statistically significant association between group and type of failures. Conclusions: Bond strength of the etch-rinse adhesive to primary prepared enamel was statistically higher than for the two self-etch systems tested, which, in turn, did not significantly differ from each other.

Evaluation of a novel dog animal model for peri-implant disease: clinical, radiographic, microbiological and histological assessment.

OBJECTIVE: To assess longitudinal peri-implant tissue evaluation in a plaque compromised ligature free dog model, clinically, radiographically, microbiologically and histologically. MATERIALS AND METHODS: Six beagle mandibular premolars and first molars were extracted. Plaque accumulated for 16 weeks. Two implants were placed per hemi-mandible. For 17 weeks, control implants (CI) in one hemi-mandible were brushed daily; test implants (TI) in the other were not. These parameters were then assessed: clinically, probing depth (PD), bleeding-on-probing (BOP), presence of plaque (PP) and clinical attachment level (CAL); radiographically, marginal bone level; microbiologically, counts for Streptococcus spp., Fusobacterium spp., Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia and total bacterial load. At week 17, histomorphometric analysis was performed (MM-ISH (mucosal margin-implant shoulder); ISH-fBIC (implant shoulder-first bone-to-implant contact); MM-aJE (mucosal margin-apical area junctional epithelium); MM-aINF (mucosal margin-apical limit of the inflammatory infiltrate); %INF (percentage of inflammatory infiltrate)). RESULTS: At week 17, TI had significant increased PD, BOP, PP and CAL versus baseline. All clinical variables presented intergroup differences. There was no intergroup difference for radiographic bone loss (p > 0.05). Total bacteria, Fusobacterium spp., A. actinomycetemcomitans and P. gingivalis had intergroup differences. There was no statistically significant intergroup difference for ISH-fBIC. CONCLUSIONS: Longitudinal microbiology evaluation detected a shift period. Final intergroup microbiological differences were the basis of W17 clinical intergroup differences, with higher values in TI. Microbiological and clinical changes detected in peri-implant tissues were compatible with onset of peri-implant disease. Despite histological inflammatory intergroup difference, no histological or radiographic intergroup bone loss was detected. CLINICAL RELEVANCE: This study set-up describes a valuable method for generating "true" early peri-implant defects without mechanical trauma.

Does Delayed Restoration Improve Shear Bond Strength of Different Restorative Protocols to Calcium Silicate-Based Cements?

The purpose of the present study was to assess the proper time to perform a restoration (immediately or delayed) after placement of two calcium silicate-based cements (CSCs) and to test the performance of two different restorative protocols regarding shear bond strength (SBS). Seventy-five acrylic blocks were randomly divided into five groups (n = 15). Specimens were filled with either ProRoot MTA (Dentsply Tulsa Dental) or Biodentine (Septodont). The restoration was performed at an immediate (12 min) or delayed (seven days) timeframe, using a resin-based flowable composite (SDR) (bonded to the CSC using a universal bonding system) or glass ionomer cement (GIC) as restorative materials. SBS was measured using a universal testing machine. Fractured surfaces were evaluated, and the pattern was registered. Statistical analysis was performed using the Dunn⁻Sidak post hoc test (P < 0.05). Biodentine/immediate SDR showed the highest mean SBS value (4.44 MPa), with statistically significant differences when compared to mineral trioxide aggregate (MTA)/GIC (1.14 MPa) and MTA/immediate SDR (1.33 MPa). MTA/GIC and MTA/immediate SDR did not present significant differences regarding SBS. No statistical differences were verified concerning mean SBS between both CSCs within the 7 day groups. MTA/delayed SDR (3.86 MPa) presented statistical differences compared to MTA/immediate SDR, whereas no differences were observed regarding Biodentine performance (Biodentine/immediate SDR and Biodentine/delayed SDR (3.09 MPa)). Bonding procedures directly on top of MTA might be preferably performed at a delayed timeframe, whereas Biodentine might allow for immediate restoration.

1-year In Vitro Evaluation of Tooth Discoloration Induced by 2 Calcium Silicate-based Cements.

INTRODUCTION: The purpose of this study was to compare tooth discoloration that occurs in teeth filled with ProRoot MTA (DENTSPLY Tulsa Dental Specialties, Tulsa, OK) or Biodentine (Septodont, Saint Maur des Fossés, France) over the course of 1 year. METHODS: Twenty-eight intact premolars were resected 2 mm apical to the cementoenamel junction and the pulp tissues extirpated via the cervical cut. After the preparation of occlusal access to the pulp chamber, specimens were assigned into 4 groups according to a stratified randomization sampling process: group 1, negative control (dry sterile cotton pellet); group 2, positive control (blood-moistened cotton pellet); group 3, ProRoot WMTA (DENTSPLY Tulsa Dental Specialties); and group 4, Biodentine. The experimental materials were condensed into the crowns and the access sealed with glass ionomer restorative cement. Color was assessed at baseline (before placement of the materials), immediately after material filling, after 6 weeks of storage, and after 1 year using the Commission International de I'Eclairage L*a*b* system. Change in color, ΔE, was compared among groups and over time using analysis of variance. RESULTS: The 4 groups showed a significant decrease in L* values over time. Differences between Biodentine and WMTA were detected after 1 year, with the greater variation associated with WMTA (P = .001). The 4 groups presented a significant increase in ΔE from baseline to 1 year. All groups revealed perceptible color changes (ΔE > 2.3) between immediately after material filling and after 6 weeks and after 6 weeks and 1 year. After 1 year, no differences could be detected between Biodentine and WMTA. CONCLUSIONS: Delayed tooth discoloration was detected for the 2 materials at the 1-year evaluation, but it was more evident for ProRoot MTA than Biodentine. Luminance was the most affected parameter, with a higher decrease for ProRoot MTA.

Thermocycling effect on microshear bond strength to zirconia ceramic using Er:YAG and tribochemical silica coating as surface conditioning.

The purpose of this study is to evaluate the thermocycling effect on the microshear bond strength (µSBS) of different self-adhesive resin cements to zirconia using tribochemical silica coating Rocatec™ (ROC) and Er:YAG as surface conditioners. Two hundred forty square-like zirconia samples were polished and randomly assigned in four groups according surface treatment applied as follows: (1) no treatment (NT), (2) silica coating with ROC, 3) Er:YAG laser irradiation (LAS: 2.940 nm, 200 mJ; 10 Hz), and (4) laser followed by Rocatec™ (LAROC). Each group was divided into two subgroups according the resin tested as follows: (A) BiFix SE (BIF) and (B) Clearfil SA (CLE). After 24 h, half of the specimens from each subgroup were tested. The other half was stored and thermocycled (5-55 °C/5,000 cycles). A µSBS test was performed using a universal testing machine (cross head speed = 0.5 mm/min). Failure modes were recorded and observed by scanning electronic microscopy. Data was analyzed with ANOVA, Student's t test, and chi-square tests, and linear regression was performed (p < 0.05). Before thermocycling, both cements showed higher µSBS results with ROC and LAROC. After aging, (1) all BIF specimens evidenced severely decreased adhesion with mostly adhesive failures and (2) CLE maintained the initial results in ROC and LAROC groups, performing better with ROC. Thermocycling did not negatively influence the resin-zirconia µSBS results in the self-adhesive resin cement containing 10-MDP when used on zirconia surface coated with silica, independently of previous Er:YAG surface treatment.

The Portuguese Society of Rheumatology position paper on the use of biosimilars.

Biotechnological drugs have become a fundamental resource for the treatment of rheumatic patients. Patent expiry of some of these drugs created the opportunity for biopharmaceutical manufacturers to develop biosimilar drugs intended to be as efficacious as the originator product but with a lower cost to healthcare systems. Due to the complex manufacturing process and highly intricate structure of biologicals, a biosimilar can never be an exact copy of its reference product. Consequently, regulatory authorities issued strict preclinical and clinical guidelines to ensure safety and efficacy equivalence and, in September 2013, the biosimilar of infliximab was the first biosimilar monoclonal antibody to be authorized for use in the European Union. The current document is a position statement of the "Sociedade Portuguesa de Reumatologia" (Portuguese Society of Rheumatology) on the use of biosimilar drugs in rheumatic diseases. Two systematic literature reviews were performed, one concerning clinical trials and the other one concerning international position papers on biosimilars. The results were presented and discussed in a national meeting and a final position document was discussed, written and approved by Portuguese rheumatologists. Briefly, this position statement is contrary to automatic substitution of the originator by the biosimilar, defends either a different INN or the prescription by brand name, supports that switching between biosimilars and the originator molecule should be done after at least 6 months of treatment and based on the attending physician decision and after adequate patient information, recommends the registration of all biosimilar treated patients in Reuma.pt for efficacy, safety and immunogenicity surveillance, following the strategy already ongoing for originators, and opposes to extrapolation of indications approved to the originator to completely different diseases and/or age groups without adequate pre-clinical, safety or efficacy data.

The dog as a model for peri-implantitis: A review.

OBJECTIVE: To analyze the current available experimental canine models for peri-implantitis. MATERIAL AND METHODS: Electronic databases of the PubMed, EBSCOhost, and Cochrane Library were searched for dog studies on peri-implantitis induction methodology, until October 31, 2012. The eligibility of the studies for this review was based on the screening of two independent reviewers. RESULTS: After screening, 50 publications were eligible for review. The most used animal model was the Beagle (n = 23). The bilateral mandible four premolar were the most extracted group of teeth (n = 20) and the majority of the studies had the placement of six implants in the jaw with only five (n = 5) of them reporting on interimplant distance. All publications reported peri-implantitis induction using ligature during a variable period of time and with a subsequent heterogeneous loss of peri-implant bone. The ligature placement and maintenance around the implant varied greatly between the publications. The constant use of ligatures, sometimes traumatically forced to the peri-implant sulcus, may influence the degree of bone loss during canine experimental peri-implantitis overlapping the contribution of implant surface to the onset and development of this pathology. CONCLUSIONS: A great heterogeneity exists among the studies reporting on the induction of peri-implantitis in canine. Experimental peri-implantitis model has suffered a change through the last years, from an exclusive ligature-induced to a ligature-induced and nonligature induced progression, thus approaching the natural occurrence of this pathology. The ideal canine peri-implantitis induction model would be a naturally occurring peri-implanititis induction without the action of any ligature.