loss of anterior teeth is a common form of injury , particularly in children and adolescents . on the other hand , elderly people , who are retaining their teeth for longer period of time , have often advanced caries or periodontal diseases which may lead to extraction of teeth . patients with lost anterior teeth require immediate attention for restoration of esthetic and functional reasons . the increased patient demand for tissue maintenance and esthetic , as well as the desire to reduce treatment costs , causes clinician to seek materials and techniques that enable minimally invasive and chairside ( direct ) fabrication on teeth replacement with fixed partial dentures ( fpds ) [ 1 , 2 ] . over the last few years , the development of fiber - reinforced composite ( frc ) has offered the dental profession the possibility of fabricating resin - bonded , esthetically good and metal - free tooth restorations for single and multiple teeth replacement . frc - fixed partial denture ( fpd ) could be an alternative to metal frame resin - bonded - fpd , and also to full - coverage - crown - retained fpd and implant supported crowns [ 3 , 4 ] . frc , made of glass fibers , is the only existing esthetically acceptable material , which can be processed in mouth to the shape of a framework of a bridge , simultaneously adhere to the remaining tooth substance , and reach the adequate strength in terms of biting function of human . many studies have focused on improvement of frc fpd 's strength [ 5 , 6 ] . the most accepted concept to fabricate frc fpds is based on the use of continuous unidirectional glass ( bundle ) fibers in dimethacrylate - polymethylmethacrylate resin matrix as a substructure for the fpd . with the frc fpds , there are two approaches on the use of the fibers : one is based on conventional tooth preparation and laboratory - made restorations , while the other is based on using the fibers in minimally invasive restoration ( conservative ) by direct or indirect fabrication . frc systems enable the use of different retainer elements even in the same fpd ( hybrid - type ) . for example , it is possible to create space for the occlusal support of the frc framework by removing old filling or to make completely surface - retained restorations when clinical conditions allow correct designing of the frc framework . in the dental literature , there are presently a limited number of clinical studies on the fiber - reinforced fpds ; however , based on those results , it is reasonable to expect frc prostheses to have good longevity , especially with those made by direct technique [ 4 , 8 , 9 ] . this paper describes clinical cases of chairside-(directly ) made frc fpds , which was used according to the principles of minimal invasiveness . thirty - sex - year - old female patient had a chief complaint of esthetics because of a gab of missing upper left lateral incisor and crown of root canal - treated canine ( figure 1 ) . after discussion with the patient , it became clear that the placement of an implant for the replacement of missing teeth was not possible due to high costs of the treatment . the fabrication of a conventional fixed partial denture was avoided and refused from patient in order to conserve the remaining tooth substance . options for the conventional treatment with implants or crown - retained fpds were remained open for the future . directly made frc fpds were chosen in order to provide good esthetics , preserve tooth substance , and postpone more invasive treatments . there was free occlusal space on the palatal surface of central incisor for frc framework to be placed . guttapercha root canal filling at the upper left canine was removed using gates glidden burs up to size 4 for the total length of 7  mm ( 4000  cycles min with water cooling ) . the individually formed glass frc post ( everstick post , sticktech ltd , turku , finland ) was prepared following the manufacturer 's instructions ( figure 2 ) . a bundle of preimpregnated glass fibers was cut to a length of 16 mm and spread from the ends for increasing the bonding surface area ( figure 3 ) . the bundle was inserted in the canal and initially light polymerized with a hand light - curing unit ( optilux-501 ) for 20  s. then the post was removed from the canal and additionally light polymerized for 40  s. the surface of the frc post system was then wetted with resin ( stick resin ) and protected from any light source by a light proof box ( 3 m - espe , germany ) until cementation . cement ( paracem universal , switzerland ) was placed on the post and the post was seated and extra cement was removed . the frc framework was extended from the palatal surface of premolar to palatal surface of central incisor passing by the frc post of the canine . after application of acid etching ( 37% phosphoric acid gel ) , the gel was rinsed thoroughly and gently air dried . adhesive resins were applied according to the manufacturer 's instructions ( scotchbond multipurpose adhesive , 3 m espe , usa ) to tooth surface . flowable composite resin ( stick flow , stickteck ltd , turku , finland ) was applied on the bonding surfaces prior placing the resin impregnated fibers ( everstick ) . the flow composite was not light cured before fibers were pressed tightly against the tooth surface using a transparent silicone package ( mold ) of the fibers . the purpose of the flow composite was to seal the space between the fibers and the enamel surface . fiber framework was fully covered with a thin layer of flow composite resin , and pontic was built up layer by layer using hybrid - type particulate filler composite resin . the shade of final veneered composite resin was selected using composite shade guide , and occlusion was carefully adjusted with articulating paper ( figures 5 and 6 ) . the occlusion was adjusted carefully to avoid any primary or premature contacts or traumatic occlusal forces to the restored teeth . the treatment outcome has been followed over three years without existence of any kind of serious problem . fourteen - year - old male patient lost his upper central incisors due to trauma by an accident ( figure 7 ) . after discussion with the patient 's father , it became clear that the placement of a single implant for the replacement of missing tooth was not possible due to patient age and high costs of the treatment . also , young age of the patient would have been a clear contraindication for an implant treatment . the fabrication of a conventional fixed partial denture was avoided in order to conserve the tooth substance because of patient 's young age . the missing teeth were planned to be replaced with an implant - retained crowns later on . directly made frc fpds were chosen in order to provide good esthetics , preserve tooth substance , and postpone the final decision on the prosthetic treatment . as described in the first clinical case , after etching and applying bonding agent , fibre - framework was extended between the palatal surfaces of lateral incisors ( figure 8) . fiber - framework was covered with a thin layer of flow composite resin , and pontic was built up by using particulate filler composite resin . the final step was the adjustment of occlusion and contouring and finishing the restoration ( figure 9 ) . laboratory - made surface - retained resin - bonded prostheses made of metals are commonly supported and bonded from one end in order to reduce the number of debondings . in the case of surface - retained frc prostheses , the framework can be supported from both ends because of better bonding characteristics and biomechanical flexibility of the frc framework . the flexibility allows abutment teeth to move without stressing the cement - framework interface in function , and loosening the prostheses . however , in the case of abutments with increased mobility , it is recommended to support also resin - bonded frc fpd from one end only . in the cantilever designs , special care has to be taken to ensure adequate design - based rigidity of the frc framework to resist bending forces by biting function . fibers of the framework should cover as large surface as possible on the abutments and , in the anterior area , should be placed close to the incisal edge to eliminate the dislodging forces . although resin - bonded frc fpds are most commonly used in the anterior and premolar regions , rather than molar region , recent laboratory investigations have suggested that optimally designed frc fpd made on nonprepared abutments can provide even higher load - bearing capacity for the fpd than conventional porcelain - fused to metal fpd can provide . thus , the development of the frc materials and technologies may allow alternatives also for directly made molar replacements . the frc framework is intended to be fully covered by veneering composite in order to obtain a polishable and tooth - coloured surface . if the frc framework is not properly covered by veneering composite , the darkness of the oral cavity can be transmitted through the connectors and can cause esthetic problems . the composition of the polymer matrix and fiber orientation has the major role in bonding ability and durability of veneered composite to the frc framework or resin luting cement . it has been concluded that preimpregnation of the fibers with the light - polymerizable dimethacrylate resin system containing linear polymer phases is of importance to optimize the interfacial adhesion of frc framework to composite veneer . using a combination of dimethacrylate monomer resin and linear polymer , which forms semi - interpenetrating polymer network ( semi - ipn ) after being polymerized , offers better bonding site for veneered composite by means of interdiffusion bonding [ 1214 ] . recent laboratory studies showed that bond strength of directly fabricated frc fpd to the tooth surface is as good as particulate filler composite .   from clinical point of view however , the longitudinal studies reported general failure rates between 5% and 16% over periods up to 4 - 5 years [ 4 , 9 , 16 ] . these finding were demonstrated for prostheses with both extracoronal and intracoronal retainer designs , but only for patients who did not exhibit sever parafunctional habits . van heumen et al . showed a survival rate of 64% after 5 years follow - up of 3-unit anterior frc prostheses made with the materials and techniques used in late 1990s . the recent clinical data , on the semi - ipn resin matrix frc fpds made directly in patients mouth , suggest high survival percentages ( > 96% at five years ) , which reflects material development and learning of fabricating frc fpds . most common failures in frc fpds reported in the earlier studies were delamination of veneering composite at pontic area , which are normally easy to be repaired in patients mouth . the current designing principles enable to fabricate frc fpd to eliminate known risks for technical failures .   as conclusion , the combination of filling composite veneer , adhesive system , and frc framework has introduced a new generation of metal - free direct teeth replacement . the most recent fabrication principles need to be followed to ensure clinical success of the restorations .