Clinical Study of Longevity of Resin-Bonded Glass Fibre Reinforced Composite Bridges:

FRC bridges proven reliable for long-term treatment

Pekka K. Vallittu
Professor (Biomaterials Science), DDS, PhD, CDT, Docent,
Specialist in Prosthodontics,
Dean of the Institute of Dentistry
University of Turku, Institute of Dentistry

According to the latest five-year clinical follow-up study1), resin-bonded glass fibre reinforced composite (FRC) bridges have a better survival rate than traditional metal alloy resin-bonded bridges .

In this study by Professor Pekka Vallittu, a total number of 29 FRC (Stick™, Stick Tech Ltd.) bridges were fabricated and monitored over a time period of up to 63 months (5.25 years). These FRC bridges were laboratory made to replace one to three missing teeth in either the maxilla or mandible. The continuous unidirectional glass fibre was used and the bridge frameworks consisted of bonding wings, inlays, complete coverage crowns or combinations of these. The overall survival rate after the follow-up period was 75% (Kaplan-Meier survival probability). Two out of 29 frameworks fractured and three became de-bonded. The de-bonded frameworks were successfully repaired in-situ leading to the overall functional survival rate of up to 93% (as presented in the graph below).

Clinically these results prove that:

Various retaining elements (inlays, crowns, surface bonding wings) can be incorporated to the bridge construction
FRC bridges are easy to repair or alter the whole construction if needed
The use of FRC’s enables minimally invasive techniques

In addition, the use of FRC’s is cost-effective and time-saving, provides excellent aesthetics and is metal-free.

“FRC’s provide more affordable treatment options for fixed partial dentures than traditional metal frame bridges or implant supported bridges. This is an obvious advantage of FRC’s – to dentists and to patients”, says Professor Pekka Vallittu. “Also, with Stick fibre reinforced composites we can tailor-make the bridge according to the patient’s need. This is tissue-saving and practicable thanks to the good bonding of the bridge structure. In addition, the good bonding of FRC’s enables minimally invasive tissue saving techniques.”

"Presently there is no evidence available to suggest whether fibre reinforced composite constructions could not function also as long-term solutions - rather the opposite. With fibre reinforced composite structures we can at least postpone the expected need for traditional bridges far into the future”, says Professor Vallittu.

1) Vallittu PK. Survival rates of resin-bonded, glass fibre-reinforced composite fixed partial denture with a mean follow-up of 42 months: A pilot study. J Prosthet Dent 2004; 91 (3): 241-246.
2) Pröbster B, Henrich GM. 11-years follow-up study of resin-bonded fixed partial dentures. Int J Prosthodont 1997; 10: 259-68.

In-vitro comparison of fracture strength between two Fiber-reinforced composite

Conclusions: EverStic resists a higher load until initial failure than FibreKor®. It can be embedded with Sculpture® or 3M composite. The study confirmed the FibreKor® is stronger when embedded with Sculpture® composite following the manufacture’s instruction than use of 3M composite.

Clinical study of longevity of fibre reinforced composite periodontal splints

Conclusions: The preliminary results of this follow-up study suggests that the glass fibre reinforced periodontal splint is a good treatment option for permanent splinting. In addition, patient's acceptance was high and the splints were considered comfortable, esthetic and easy to maintain.

Reinforcing Dentures

Doctoral thesis on reinforcing dentures with fibre reinforcements

Glass fibre bridges vs. metal frameworks

Glass fibre reinforced bridges overcome the problems of traditional metal frameworks.

CLINICAL DATA:
35 - 40 chairside bridges with 100% functional survival rate

LABORATORY DATA:
2703 laboratory restorations with 99.4% functional survival rate

FRC bridges vs. PFM bridges

Doctoral thesis by DMD MSc Scott R. Dyer, April 22, 2005:

Fibre-reinforced composite bridges stronger than conventional porcelain fused to metal bridges

Original FRC related research articles

Meiers J, Freilich M. Use of a prefabricated fiber-reinforced composite resin framework to provide a provisional fixed partial denture over an integrating implant: a clinical report. J Prosthet Dent 2006; 95: 14-18.

Meiers JC, Freilich MA. Design and use of a prefabricated fiber-reinforced composite substructure for the chairside replacement of missing premolars. Quintessence Int 2006; 37: 449-454.

Bouillaguet A, Scütt A, Alander P, Schwaller P, Buerki G, Michler J, Cattani-Lorente M, Vallittu PK, Krejci I. Hydrothermal and mechanical stresses degrade fiber-matrix interfacial bond strength in dental fiber-reinforced composites. J Biomed Mater Res Part B; Appl Biomater 2006; 76B: 98-105.

Kargul B, Caglar E, Kabalay U. Glass fiber-reinforced composite resin as fixed space maintainer in children: 12-month clinical follow-up. J Dent Child 2005; 72: 109-112.

Garoushi SK, Ballo AM, Lassila LVJ, Vallittu PK. Fracture resistance of fragmented incisal edges restored with fiber-reinforced composite. J Adhes Dent 2006; 8: 91-95.

Sadeghi M. Bond strength of glass fiber reinforced composite and base metal frameworks used in resin-bonded fixed partial dentures. Beheshti Univ Dent J 2005; 22: 95-99.

Sadeghi M, Richards L. In vitro study of fracture strength of resin-bonded glass fiber-reinforced composite anterior fixed partial dentures. Dent Res J 2005; 2: 14-18.

Meiers JC, Kazemi RB. Chairside replacement of posterior teeth using a prefabricated fiber-reinforced resin composite framework technique: a case report. J Esthet Restor Dent 2005; 17: 335-342.

Fennis WMM, Terzvergil A, Kuijs RH, Lassila LVJ, Kreulen CM, Creugers NHJ, Vallittu PK. In vitro fracture resistance of fiber reinforced cups-replacing composite restorations. Dent Mater 2005; 21(6): 565-72.

Fokkinga WA, Le Bell AM, kreulen CM, Lassila LVJ, Vallittu PK, Creugers NHJ. Ex vivo fracture resistance of direct resin composite complete crowns with and without ports on maxillary premolars. Int Endod J 2005; 38: 230-7.

Uctasli S, Terzvergil A, Lassila LVJ, Vallittu P. The degree of conversion of fibre-reinforced composites polymerized using different light-curing sources. Dent Mater 2005; 21(5): 469-75.

Visser HJ, Jansen van Rensburg JJ. fibre reinforced composites—alternative for lost teeth replacement. SADJ 2005; 60(1): 20-2.

Artega S, Meiers JC. Single-tooth replacement with a chairside prefabricated fiber-reinforced resin composite bridge: a case study. Gen Dent 2004; 52(6): 517-9.

El-Mowafy O. Polymerization shrinkage of restorative composite resins. Pract Proced Aesthet Dent 2004; 16(6). 452-3, 455.

Freilich MA, Duncan JP, Alarcon EK, Eckrote KA, Goldberg AJ. The design and fabrication of fiber-reinforced implant prostheses. J Prosthet Dent 2002; 88: 449-54.

Chai J, Takahashi Y, Hisama K, Shimizu H. Effect og water storage on the flexural properties of three glass fiber-reinforced composites. Int J Prosthodont. 2005; 18: 25-33.

Mannocci F, Sherriff M, Watson TF, Vallittu PK. Penetration of bonding resins into fibre-reinforced composite posts: a confocal microscopic study. Int Endod J 2005; 38(1): 46-51.

Fokkinga WA, Kreulen CM, Vallittu PK. A structured analysis of in vitro failure loads and failure modes of fiber, metal, and ceramic post-and-core systems. Int J Prosthodont 2004; 17: 476-482.

Geserick M, Ball J, Wichelhaus A. Bonding fiber-reinforced lingual retainers with color-reactivating flowable composite. J Clin Orthodontics 2004; XXXVII(10): 560-562.

Szabo G, Benke B. [Glass fiber polymerization--an effective method of increasing fracture resistance of the denture base (case report)] Fogorv Sz 2003; 96: 211-5 (Hungarian).

Xie QF, Zhang L, Zheng G. [Mechanical properties of preimpregnated glass fiber composite resins]. Hua Xi Kou Qiang Xue Za Zhi 2004; 22: 317-9 (Chinese).

Aydin MY, Kargül B. Glass-fiber reinforced composite in management of avulsed central incisor: a case-report. J dent Child (Chic). 2004; 71: 66-8.

Freilich MA, Meiers JC. Fiber-reinforced composite prostheses. Dent Clin N Am 2004; 48: 545-562.

Kim SH, Watts DC, Effect of fiber reinforcement and water storage on fracture toughness (KIC) of polymer-based provisional crown and FPD materials. Int J Prosthod 2004; 17: 318-322.

Chai J, Takahashi Y, Hisama K, Shimizu H. Water sorption and dimensionsl stability of three glass fiber-reinforced composites. Int J Prosthodont. 2004; 17: 195-9.

Hamza TA, Rosenstiel SF, Elhosary MM, Ibraheem RM. The effect of fiber reinforcement on the fracture toughness and flexural strength of provisional restorative resins. J Prosthet Dent. 2004; 91: 258-264.

Kim SH, Watts DC. The effect of reinforcement with woven E-glass fibers on the impact strength of compelete dentures fabricated with high-impact acrylic resin. J Prosthet Dent. 2004; 91: 274-280.

Butterworth C, Ellakwa AE, Shortall A. Fibre-reinforced composites in restorative dentistry. Dent Update 2003; 30: 300-306.

Kargül B, Caglar E, Kabalay U. Glass fiber reinforced composite resin space maintainer: case reports. J Dent Child (Chic) 2003; 70(3): 258-61.

Säilynoja ES, Shinya A, Gomi H, Ishii Y. The effect of immersion temperature on the flexural strength of a pre-coated fiber reinforced composite resin. Prosthodontic Research & Practice, 2003; 2: 1-10.

Hugo B. Direkte kompositbrüken im frontzahnbereich. Quintessenz: 2003; 11: 1163-1175. (in Germany).

Hugo B. Intraoral hergestellte glasfaserverstärkte Kompositbrücken zum Ersatz einzelner Frontzähne (Chairside fiber-reinforced resin composite fixed partial dentures). Inf Orthod Kieferorthop 2003; 35: 55-63. (in Germany).

Bouillaguet et al Zähnärtzliche Mitteilungen, 2003; 93: 44-50 (in Germany).

Bouillaguet S, Schutt A, Marin I, Etechami L, Di Salvo G, Krejci I. Replacement of missing teeth with fiber-reinforced composite FPDs: clinical protocol. Pract Proced Aesthet Dent, 2003; 15: 195-202.

Ylimaz H, Aydin C, Caglar A, Yasar A. The effect of glass fiber reinforcement on the residual monomer content of two denture base resins. Quintessence Int. 2003; 34:148-53.

Xu, H.H.K., Schumacher, G.E., Eichmiller, F.C., Peterson, R.C., Antonucci, J.M., Mueller, H.J. Continuous-fiber preform reinforcement of dental resin composite restorations. Dental Materials 19 (2003); 523-530.

Kallio P, Moxom R. Pre-impregnated flass-fibre reinforced splints and bridges in the occlusal therapy of preiodontitis, part two. Restorative & Aesthetic Dentistry 2002; 4: 97-102.

Kallio P, Moxom R. Pre-impregnated flass-fibre reinforced splints and bridges in the occlusal therapy of preiodontitis, part one. Restorative & Aesthetic Dentistry 2002; 4: 73-81.

Ellakwa AE, Shortall AC, Marquis PM. Influence of fiber type and wetting agent on the flexural properties of an indirect fiber reinfoced composite. J Prosth Dent 2002; 88: 485-490.

B. Kargül, U.Kabalay, E.Cailar. Glassfibre reinforced composite resin bonded space maintainers. European Journal of Paediatric Dentistry; Vol. 3 September 2002.

Ayman E. Ellakwa, Peter M. Marquis. Influence of fiber type and wetting agent on the flexural properties of an indirect fiber reinforced composite. The Journal of Prosthetic Dentistry 2002; 88:485-90.

Cemal Aydin, Handan Yilmaz, Alper Caglar. Effect of glass fiber reinforcement on the flexural strength of different denture base resins. Quintessence 2002; vol. 33, number 6: 457-463.

Kolbeck C, Rosentritt M, Behr M, Lang R, Handel G. In vitro examination of the fracture strength of 3 different fiber-reinforced composite and 1 all-ceramic posterior inlay fixed partial denture systems. J Prosthod 2002; 11(4): 248-253.

Ahlstrand Wisua M, Finger Werner J. Direct and indirect fiber-reinforced fixed partila dentures: Case reports. Quintessence 2002; vol. 33, number 5: 359-365.

Articles published by Pekka Vallittu and/or his research group:

Narva KK, Lassila VJ, Vallittu PK. Flexural fatigue of denture base polymer with fiber-reinforced composite reinforcement. Comp: Part A 2005; 36: 1275-1281.

Tanner J, Robinson C, Söderling E, Vallittu P. Early plaque formation on fibre-reinforce composites in vitro. Clin Oral Inverst 2005; 9: 154-160.

Terzvergil A, Lassila LV, Vallittu PK, the shear bond strength of bidirectional and random-oriented fibre-reinforced composite to tooth structure. J Dent 2005; 33(6): 509-16.

Dyer SR, Lassila LVJ, Alander P, Vallittu PK. Static strength of molar region direct technique glass fibre-reinforced composite fixed partial dentures. J Oral Rehabilit 2005; 32: 351-357.

Narva KK, Lassila LV, Vallittu PK. The static strength and modulus of fiber reinfoeced denture base polymer. Dent Mater 2005; 21: 421-428.

LeBell AM, Tanner J, Lassila LVJ, Kangasniemi I, Vallittu PK. Bonding of composte resin luting cement to fiber-reinforced composite root canal posts. J Adhes Dent 2004; 6: 319-325.

Alander P, Lassila L, Vallittu P. The span length and cross-sectional design affect values of strength. Dent Mater 2005; 21: 347-353.

Aho AJ, Hautamäki M, Mattila R, Alander P, Strandberg N, Rekola J, Gunn J, Lassila LV, Vallittu PK. Surface porous fibre-reinforced composite bulk bone substitute. Cell Tissue Bank 2004; 5(4): 213-21.

Tuusa SM, Puska MA, Lassila LV, Vallittu PK. Residual monomers released from glass-fibre-reinforced composite photopolymerized in contact with bone and blood. J Mater Sci Mater Med 2005; 16(1): 15-20.

Lahdenperä MS, Puska MA, Alander PM, Waltimo T, Vallittu PK. Release of chlorhexidine difluconate and flexural properties of glass fibre reinforced provisional fixed partial denture polymer. J Mater Sci Mater Med 2004; 15: 1349-1353

Dyer SR, Lassila LV, Jokinen M, Vallittu PK. Effect of fibre position and orientation on fracture load of fibre-reinforced composite. Dent Mater 2004; 20(10): 947-55.

Lassila LVJ, Tanner J, Le Bell AM, Narva K, Vallittu PK. Flexural properties of fiber reinforced root canal posts. Dent mater 2004; 20: 29-36.

Waltimo T, Luo G, Samaranyake LP, Vallittu PK. Glass fibre-reinforced composite laced with chlorhexidine digluconate and yeast adhesion. J Mater Sci Mater Med 2004; 15: 117-121.

Puska MA, Närhi TO, Aho AJ, Yli-Urpo A, Vallittu PK. Flexural properties od crosslinked and oligomer-modified glass-fibre reinforced acrylic bone cement. J Mater Sci Mater Med 2004; 15: 1037-43.

Keski-Nikkola MS, Lassila LVJ, Vallittu PK. An in vitro investigation of bond strength of veneering composite resin to glass fibre veil reinforced composite. Eur J Prosthodont Res Dent 2004; 12: 80-86.

Lassila LVJ, Vallittu PK. The effect of fiber position and polymerization condition on the flexural properties of fiber-reinforced composite. J Cont Dent Pract 2004; 5(15): 1-12.

Tezvergil A. Lassila LVJ. Yli-Urpo A. Vallittu PK. Repair bond strength of restorative resin composite applied to fiber-reinforced composite substrate, Acta Odontol Scand 2004; 62: 51-60.

Alander P, lassila LVJ, Tezvergil A Vallittu PK. Acoustic emission of fiber-reinforced composite in flexural testing, Dent Mater 2004; 20: 305-312.

Vallittu PK. Survival rates of resin-bonded, glass fiber-reinforced composite fixed partial dentures with a mean follow-up of 42 months: A pilot study. J Prosthet Dent. 2004; 91: 241-246.

Narva KK, Lassila LV, Vallittu PK, Fatigue resistance and stiffness of glass fiber-reinforced urethane dimethacrylate composite. J Prosthet dent. 2004 feb; 91(2): 158-63.

Lassila LVJ, Tanner J, Le Bell AM, Narva K, Vallittu PK. Flexural properties of fiber reinforced root canal posts. Dent Mater 2004; 20: 29-36.

Trezvergil A, Lassila LVJ, Vallittu PK. Strength of adhesive-bonded fiber-reinforced composites to enamel and dentin substrates. Adhesive Dent 2003; 4: 301-311.

Tezvergil A, Lassila LV, Vallittu PK. Composite-composite repair bond strength: effect of different adhesion primers. Dent Mater 2003; 19(8): 521-5.

Karacaer O, Polat TN, Tezvergil A, Lassila LV, Vallittu PK. The effect of length and concentration of glass fibers on the mechanical properties of an injection- and a compression-molded denture base polymer. J Prosthet Dent 2003; 90(4): 385-93.

Ozcan M, Vallittu PK. Effect of surface conditioning methods on the bond strength of luting cement to ceramics. Dent Mater. 2003 Dec;19(8):725-31.

Närhi TO, Tanner J, Ostela I, Narva K, Nohrstrom T, Tirri T, Vallittu PK. Anterior Z250 resin composite restorations: one-year evaluation of clinical performance. Clin Oral Investig. 2003 Sep 18 [Epub ahead of print]

Le Bell AM, Tanner J, Lassila LV, Kangasniemi I, Vallittu PK. Depth of light-initiated polymerization of glass fiber-reinforced composite in a simulated root canal. Int J Prosthodont. 2003;16(4):403-8.

Vallittu PK, Kurunmaki H. Bond strength of fibre-reinforced composite to the metal surface. J Oral Rehabil. 2003;30(9):887-92.

Tezvergil A, Lassila LV, Vallittu PK. The effect of fiber orientation on the thermal expansion coefficients of fiber-reinforced composites. Dent Mater. 2003;19(6):471-477.

Tanner J, Carlen A, Soderling E, Vallittu PK. Adsorption of parotid saliva proteins and adhesion of Streptococcus mutans ATCC 21752 to dental fiber-reinforced composites. J Biomed Mater Res. 2003;15;66B(1):391-8.

Polat TN, Karacaer O, Trevergil A, Lassila LV, Vallittu PK. Water sorption, solubility and dimensional changes of denture base polymers reinforced with short glass fibers. J. Biomater Appl. 2003:17;321-35.

Rantala, L.I., Lastumäki, T.M., Peltomäki, T., Vallittu, P.K. Fatique resistance of removable orthodontic appliance reinforced with glass fibre weave. Journal of Oral Rehabilitation 2003; 30:501-506.

Lastumäki, TM, Kallio, TT, Vallittu PK. The bond strength of light-curing composite resin to finally polymerized and aged glass fiber-reinforced composite substrate. Biomaterials 2002;23: 4533-4539.

Vallittu PK. Faserverstärkte Komposite (FRC) in der zahnärztlichen Prothetik. Deutsche Zahnärztliche Zeitschrift 57 (2002), 7; 399-405.

Vallittu PK. Use of woven glass fibres to reinforce a composite veneer. A fracture resistance and acoustic emission study. J Oral Rehabil 2002;29:423-429.

Lassila LVJ, Nohrström T, Vallittu PK. Influence of water sorption on properties of unidirectional fiber composite. Biomater 2002;2002:23;2221-9

Waltimo T, Vallittu PK, Haapasalo M. Adherence of Candida species to newly polymerized and water-stored denture base polymer. Int J Prosthodont 2001;14:457-460.

Tanner J, Vallittu PK, Söderling E. Effect of water storage of E-glass fiber-reinforced composite on adhesion of Streptococcus mutans. Biomater 2001;22:1613-1618.

Narva K, Vallittu PK, Yli-Urpo A. Clinical survey of acrylic resin removable denture repairs with glass-fiber reinforcement. Int J Prosthodont 2001;14:219-224.

Kallio T, Lastumäki T, Vallittu PK. Bonding of restorative composite resin to some polymeric composite substrates. Dent Mater 2001;17:80-86.

Vallittu PK. Effect of 180 weeks water storage on the flexural properties of E-glass and silica fiber acrylic resin composite. Int J Prosthodont 2000;13:334-339.

Lastumäki T, Lassila L, Vallittu PK. Flexural properties of bulk fiber-reinforced composite DC-Tell used in fixed partial dentures. Int J Prosthodont 2001;14:22-26.

Miettinen VM, Vallittu PK, Forss H. Release of fluoride from glass fibre -reinforced composite with multiphase polymer matrix. J Mater Mater Med 2001;12:503-505.

Lassila LVJ, Vallittu PK. Denture base polymer Alldent Sinomer: mechanical properties, water sorption and release of residual compounds. J Oral Rehabil 2001;28:607-613.

Sewón LA, Ampula L, Vallittu PK. Rehabilitation of a periodontal patient with rapidly progressing marginal alveolar bone loss. A case report. J Clin Periodontol 2000; 27:615-619. Vallittu PK. A case report: A glass fibre reinforced composite resin bonded fixed partial denture. Eur J Prosthodont Rest Dent 2001;9:35-39.

Nohrström TJ, Vallittu PK, Yli-Urpo A. The effect of position and quantity of glass fibers on the fracture resistance of provisional fixed partial denture. Int J Prosthodont 2000;13:72-78.

Vallittu PK, Sevelius C. Resin-bonded, glass fiber reinforced composite fixed partial dentures - A clinical study. J Prosthet Dent 2000;84:413-418.

Tanner J, Vallittu PK, Söderling E. Adherence of Streptococcus mutans to an E-glass fiber -reinforced composite and conventional restorative materials used in prosthetic dentistry. J Biomed Mater Res 2000;49:250-256.

Vallittu PK. Prosthodontic treatment with glass fiber reinforced composite resin bonded fixed partial denture. A clinical report. J Prosthet Dent 1999;82:132-135.

Vallittu PK. Flexural properties of acrylic polymers reinforced with unidirectional and woven glass fibers. J Prosthet Dent 1999;81:318-326.

Vallittu PK, Ekstrand K. In vitro cytotoxicity of fiber-polymethyl methacrylate composite used in dentures. J Oral Rehabil 1999;26:666-671.

Vallittu PK. Unpolymerized surface layer of autopolymerizing polymethyl methacrylate resin. J Oral Rehabil 1999;26:208-212.

Waltimo T, Tanner J, Vallittu PK, Haapasalo M. Adherence of Candida albicans to the surface of polymethylmethacrylate E glass fiber composite used in dentures. Int J Prosthodont 1999;12:83-86.

Miettinen VM, Narva K, Vallittu PK. Water sorption, solubility and post-curing of glass fibre reinforced polymers. Biomater 1999;20:1187-1194.

Lassila LVJ, Vallittu PK. Effect of water and artificial saliva on the fatigue resistance of cobalt-chromium dental alloy. J Prosthet Dent 1998;80:708-713.

Vallittu PK, Ruyter IE, Ekstrand K. Effect of water storage on the flexural properties of E-glass and silica fiber acrylic resin composite. Int J Prosthodont 1998;11:340-350.

Vallittu PK. The effect of glass fiber reinforcement on the fracture resistance of a provisional fixed partial denture. J Prosthet Dent 1998:79:125-130.

Vallittu PK. Compositional and weave pattern analyses of glass fibers in dental polymer fiber composites. J Prosthod 1998;7:170-176.

Vallittu PK. Some aspects of the tensile strength of unidirectional glass fiber - polymethyl methacrylate composite used in dentures. J Oral Rehabil 1998;25:100-105.

Vallittu PK, Narva K. Impact strength of a modified continuous glass fiber-polymethylmethacrylate composite. Int J Prosthodont 1997;10:142-148.

Vallittu PK. Oxygen inhibition of autopolymerization of polymethylmethacrylate - glass fibre composite. J Mater Sci Mater Med 1997;8:489-492.

Vallittu PK. Glass fiber reinforcement in repaired acrylic resin removable dentures: Preliminary results of a clinical study. Quintessence Int 1997;28:39-44.

Vallittu PK. Transverse strength, ductility, and qualitative elemental analysis of cobalt-chromium alloy after various durations of induction melting. J Prosthod 1997;6:55-60.

Vallittu PK. Curing of silane coupling agent and its effect on the transverse strength of autopolymerizing polymethylmethacrylate-glass fibre composite. J Oral Rehabil 1997:24:124-130.

Vallittu PK. Ultra-high-modulus polyethylene ribbon as reinforcement for denture polymethyl methacrylate: A Short communication. Dent Mater 1997;13:381-382.

Miettinen VM, Vallittu PK. Water sorption and solubility of glass fiber reinforced denture polymethyl methacrylate resin. J Prosthet Dent 1997;77:531-534.

Miettinen VM, Vallittu PK. Release of residual methyl methacrylate into water from glass fiber - polymethyl methacrylate composite used in dentures. Biomater 1997;18:181-185.

Vallittu PK. Some factors affecting the transverse strength of repaired denture acrylic resin. Eur J Prosthodont Rest Dent 1996;4(1):7-9.

Vallittu PK. Dimensional accuracy and stability polymethylmethacrylate reinforced with metal wire or with continuous glass fiber. J Prosthet Dent 1996;75:617-621.

Vallittu PK. Fatigue resistance and stress of wrought-steel wire clasps. J Prosthodont 1996;5:186-192.

Vallittu PK. Comparison of the in vitro fatigue resistance of acrylic resin partial denture reinforced with continuous glass fibers or metal wire. J Prosthod 1996;5:115-121.

Vallittu PK. Impregnation of glass fibres with polymethylmethacrylate by using a powder coating method. Applied Composite Materials 1995;2:51-58.

Vallittu PK, Kokkonen M. Deflection fatigue of a cobalt-chromium, titanium and gold alloy cast denture clasp. J Prosthet Dent 1995;74:412-419.

Vallittu PK, Vojtkova H, Lassila VP. Impact strength of denture polymethyl methacrylate reinforced with continuous glass fibers or metal wire. Acta Odontol Scand 1995;53:392-396.

Vallittu PK. The effect of void space and polymerization time on transverse strength of acrylic - glass fibre composite. J Oral Rehabil 1995;22:257-261.

Vallittu PK, Lassila VP, Lappalainen R. Transverse strength and fatigue of denture acrylic-glass fiber composite. Dent Mater 1994;10:116-121.

Vallittu PK. Acrylic resin-fiber composite - Part II: the effect of polymerization shrinkage of polymethyl methacrylate applied to fiber roving on the transverse strength. J Prosthet Dent 1994;71:613-617.

Vallittu PK, Lassila VP, Lappalainen R. Acrylic resin - fiber composite - Part I: The effect of fiber concentration on fracture resistance. J Prosthet Dent 1994;71:607-612.

Vallittu PK, Lassila VP, Lappalainen R. Evaluation of damage to removable dentures in two cities in Finland. Acta Odontol Scand 1993;51:363-369.

Vallittu PK. Comparison of two different silane compounds used for improving adhesion between fibers and acrylic denture base material. J Oral Rehabil 1993;20:533-539.

Vallittu PK. Effect of some properties of metal strengtheners on the fracture resistance of acrylic denture base material construction. J Oral Rehabil 1993;20:241-248.

Vallittu PK, Lassila VP. Effect of metal strengthener's surface roughness on fracture resistance of acrylic denture base material. J Oral Rehabil 1992;19:385-391.

Vallittu PK, Lassila VP. Reinforcement of acrylic resin denture base material with metal or fibre strengtheners. J Oral Rehabil 1992;19:225-230.