***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: PURPOSE The objective of this research was to test the hypothesis that 3-unit fixed partial dentures ( FPDs ) made from a moderately high-strength core ceramic will adequately resist fracture in posterior regions if fabricated with a minimal connector size of 4 mm . MATERIAL S AND METHODS Thirty ceramic FPD core frameworks were prepared using a hot-pressing technique and a lithia disilicate-based core ceramic . The maximum occlusal force was measured for each patient prior to tooth preparation . Connector heights and widths were measured for each FPD . Patients were recalled annually after cementation for 4 years and evaluated using 11 clinical criteria . All FPDs were examined by 2 independent clinicians , and rankings for each criterion were made from 1 to 4 ( 4 = excellent ; 1 = unacceptable ) . RESULTS The fracture rate was approximately 3 % per year , and the proportion of good overall ratings in the nonfractured FPDs was reduced by more than 6 % per year , where a good overall rating was defined to be a rank of 3 or 4 in all 11 criteria . There was little evidence that the use of either resin-reinforced glass-ionomer cement ( Protec CEM ) or dual-cure resin cement ( Variolink II ) made any difference in terms of fracture rate or overall rating ( P= .30 , .63 , .97 , and .71 for the 4 years , respectively ) . From a fracture resistance perspective , 4 of the 30 ceramic FPDs  fractured within the 4-year evaluation period , representing an 86.7 % success rate . Another FPD was replaced because of a caries lesion on 1 abutment tooth away from the margin . One FPD fracture was associated with the subject having the greatest occlusal force ( 1,031 N ) . The other 2 fractures were associated with FPDs that exhibited connector heights of less than 3 mm . All criteria were ranked good to excellent during the 4-year period for the remaining FPDs . CONCLUSION Fractured FPDs were associated with a connector height of less than 4 mm ; thus , the hypothesis was accepted PURPOSE The aim of this prospect i ve study was to evaluate the clinical efficacy and long-term survival rate of  three-unit fixed partial dentures ( FPDs ) made from lithium disilicate-based core ceramic . MATERIAL S AND METHODS Twenty-one three-unit FPDs were placed in 19 patients to replace single lost teeth in the esthetic area , following a study protocol that took clinical , esthetic , and radiologic aspects into consideration . Each case was review ed at 1 week following placement , at 6 months , and then annually for 10 years . Statistical analysis was performed using Kaplan-Meier survival analysis . RESULTS Out of the 19 patients , 14.3 % presented reversible postoperative sensitivity . Recession was observed in 24 % of dental posts , and 7.1 % presented marginal discoloration . Treatment did not increase either Bleeding or Plaque Index scores at prepared teeth ; secondary caries did not appear either . The restorations ' survival rate at the 10-year follow-up was 71.4 % ; six FPDs had fractured and one debonded . CONCLUSIONS Fracture failure rate was 28.6 % after 10 years ; a high percentage corresponded to connector fractures and occurred during the first 5 years . Lithium disilicate glass-ceramic FPDs present a higher risk of fracture than st and ard therapies ( metal-ceramic ) or other more recently developed ceramic material s. The prognosis for survival improves for Class I occlusion and nonparafunctional patients This clinical study evaluated posterior three-unit fixed dental prostheses ( FDPs ) made of zirconia substructures veneered with pressable glass – ceramic .  Nineteen patients received 21 FDPs replacing either the second premolar , first molar , or second molar . The FDPs were cemented with glass ionomer . Recall examinations were performed every 12 months . The mean service time of the FDP was 40 months . At 30 months , one maxillary FDP exhibited zirconia framework fracture at a thinned occlusal area of the abutment . Loss of retention led to the removal of one FDP after 38 months . The Kaplan – Meier survival probability was 90.5 % after 40 months for all types of failures and 95.2 % concerning framework fractures . The overpressing technique appears to be reliable in terms of the veneering material . However , one framework fracture was observed in this study PURPOSE This study prospect ively evaluated the clinical performance of posterior zirconium-oxide-based all-ceramic fixed partial dentures ( FPDs ) . METHODS Forty-two abutments of 21 Cercon FPDs were fitted in 20 patients at the Tsurumi University Dental Hospital from August 2005 to August 2006 . The performance of these FPDs was evaluated using the California Dental Association ( CDA ) quality assessment system at baseline and at all follow-up examinations . RESULTS All FPDs were examined after a mean observation period of 28.1 ( + /-3.4 ) months . During the observation period , no fracturing of FPDs was seen . All of the FPDs examined were rated as satisfactory with regard to all factors at the follow-up examinations based on the CDA quality assessment criteria . CONCLUSION Within the limitations of this short-term clinical study , no core framework fractures were seen . According to the CDA criteria , 100 % of the FPDs were rated as satisfactory during this observation period The clinical question at issue , whether it is possible to combine implants and natural teeth via fixed bridges , is of current interest . The treatment of the subjects of this prospect i ve study was performed between June 1984 and December 1986 . This article presents the 5-year results of the study . The consecutive patient material comprised 23 patients with Applegate Kennedy Class I residual dentition in the m and ible and a complete maxillary denture . All 23 patients were provided with implants ad modum Brånemark  in each m and ibular quadrant . One side was r and omized to rehabilitation with fixed bridge between the distal tooth of the residual dentition and an implant ; the other side received a free-st and ang bridge on 2 implants . The fixture survival rate was 88 % . No difference was found between the two sides . Bridge stability was 89 % for the implant bridges and 91 % for the combination bridges . The change in marginal bone level at the implants  was small during the 5-year follow up period ( on average 0.1 - 0.3 mm ) and with no difference between the two sides . In conclusion , it was not possible to demonstrate any higher risk of implant or prosthetic failure for tooth-implant fixed bridges compared with implant-supported bridges OBJECTIVE To evaluate the clinical performance of zirconia-based cantilever fixed dental prostheses ( FDPs ) . METHOD AND MATERIAL S Twenty-one cantilever FDPs with three or four units were design ed to replace one premolar or incisor ( no canines ) . The FDPs were divided into 11 zirconia cantilever FDPs ( test group ) and 10 metal-ceramic cantilever FDPs ( control group ) and r and omly assigned to patients . The results documented included failures , complications , plaque accumulation , and esthetic performance . Statistical analysis was performed using the Mann-Whitney U and chi-square tests . RESULTS During the 2-year observation period , a total of five clinical ly relevant complications in four patients occurred : three endodontic problems ( two in the test group and one in the control group ) and two veneer chippings ( both in the test group ) . Plaque accumulation on the abutment teeth was not significantly different among groups . The esthetic performance of all FDPs was acceptable . CONCLUSION Stability and esthetic performance were acceptable for all-ceramic cantilever FDPs fabricated with zirconia . A longer observation period and larger sample size are necessary to make valid predictions about the longevity of these restorations This study aim ed to evaluate three- and four-unit posterior fixed partial dentures ( FPDs ) with zirconia frameworks after 5 years of function . Of the initial 30 subjects , 25 patients with 25 FPDs were examined after a mean follow-up period of 62.1 months . Five patients were not available for recall visits . Two FPDs failed before the 60-month evaluation because of framework fracture or delamination of the veneering ceramic after endodontic treatment . The 5-year survival rate was 92 % . Based on these results , it can be suggested that zirconia frameworks have sufficient mechanical requirements for use in the stress-bearing posterior region . Major fracture of the ceramic veneer could be related to inadequate framework design or bruxism The aim of this r and omized controlled trial was to evaluate the clinical performance of lithium disilicate fixed partial dentures ( FPDs ) .  Eighteen patients received lithium disilicate FPDs ( study group ) , and 19 patients received porcelain-fused-to-metal FPDs ( control ) .  After 6 years , the survival probabilities were found to be 63 % in the study group and 95 % in the control group ( log-rank test , P = .028 ) . The data suggest that strict conditions should be considered before the use of lithium disilicate glass-ceramic for FPDs OBJECTIVES The purpose of this prospect i ve study was to evaluate the clinical outcome of  crown-retained fixed dental prostheses ( FDPs ) made  from a lithium-disilicate glass-ceramic ( IPS e.max Press , Ivoclar-Vivadent ) . METHODS Thirty-six three-unit FDPs were placed in 28 patients . The FDPs replaced teeth in the anterior ( 16 % ) and posterior ( 84 % ) regions . All teeth were prepared following a st and ardized protocol . The size of the proximal connector of the FDPs was 12 mm2 ( anterior ) or 16 mm2 ( posterior ) . FDPs were cemented either with glass-ionomer cement ( n=19 ) or composite resin ( n=17 ) . The following parameters were evaluated at baseline , 6 months after cementation and then annually ( at abutment and contralateral teeth ) : probing pocket depth , plaque index , bleeding on probing , and tooth vitality . RESULTS Three FDPs were defined as drop-out . The mean observation period of the remaining 33 FDPs was 86 months ( range : 67 - 98 months ) : two FDPs in two patients had to be replaced ( 6 % ) because of fractures . The 8-year survival rate according to Kaplan-Meier was 93 % . In addition , chipping of the veneering material was found in two FDPs ( 6 % ) . Two abutments ( 3 % ) of two restorations had to be treated endodontically ; and two FDPs ( 6 % ) lost retention and had to be recemented . These complications did not affect the function of the involved restorations clinical ly . There were no significant differences between the periodontal parameters of the test and control teeth . SIGNIFICANCE Short-span crown-retained three-unit FDPs made from lithium-disilicate glass-ceramic can be used clinical ly irrespective of an adhesive or conventional cementation STATEMENT OF PROBLEM A new method for fabrication of  crowns and fixed partial dentures  ( Procera system ) that involves electric discharge machining and copy milling has been developed . The metal used is unalloyed titanium , which can be processed as a single coping or multiple units joined to a pontic by laser welding . PURPOSE The single-unit coping or the fixed partial denture ( FPD ) substructure is then veneered with a low-fusing porcelain . MATERIAL AND METHODS In this article the clinical application of this technique was evaluated by six major universities in the United States . A total of 114 patients participated in this study , which involved 126 restorations ( 55 maxillary and 71 m and ibular prostheses ) . There were 179 abutments , of which 73 were crowns  and 53 were three-unit FPDs .  Surface and color , anatomic form , and margin integrity were assessed 1 month after cementation and at 1 year with the California Dental Association ( CDA ) quality assessment evaluation system . RESULTS No statistically significant differences in CDA scores between the 1 month evaluations and the 1 year assessment s were found for surface and color ( p = 0.68 ) , anatomic form ( p > 0.99 ) , or margin integrity ( p = 0.57 ) . By use of the lowest ranking in the three categories as the overall quality of the restoration , only 3.3 % ( two crowns and two FPDs ) were not acceptable at the 1-month visit and 4.5 % ( two crowns and three FPDs ) were not acceptable at the 1-year evaluation . At-the 1-month visit 96.6 % ( 114 ) of the restorations were considered to be satisfactory , whereas 95.5 % ( 107 restorations ) were evaluated similarly at the 1-year evaluation . CONCLUSIONS The Procera system demonstrated , by use of the CDA criteria , its capability to produce quality prostheses that were rated satisfactory more than 95 % of the time after insertion and maintained this high rating at least for 1 year OBJECTIVES To report the results at year three of an evaluation of fixed-fixed all-ceramic bridges , constructed in a yttria oxide stabilized tetragonal zirconium oxide polycrystal ( Y-TZP ) substructure , placed in adult patients in UK general dental practice s and luted using a self-adhesive resin-based c 
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Both treatments show an almost equally low complication rate , but there is a low level of reporting of hard and soft tissue conditions and PROM .
It is concluded that implant-supported 3-unit FDPs seem to be a reliable treatment with survival rates not significantly different from the results of teeth-supported 3-unit FDPs