A Piece of Tooth Is Missing: An All-Ceramic Crown, Veneer, or 3D-Milled Restoration? First Ask “How Much Tooth Structure Remains?” and “Where Is the Defect?”

A Piece of Tooth Is Missing: An All-Ceramic Crown, Veneer, or 3D-Milled Restoration? First Ask “How Much Tooth Structure Remains?” and “Where Is the Defect?”

Direct answer: All-ceramic crowns, veneers and 3D-milled restorations are not a ranking within one contest but different answers to different extents of defect — the more intact the enamel that remains, the better bonded veneers survive [F2]; in a small cross-arch randomised trial on endodontically treated posterior teeth in the mandibular arch, full crowns had the higher survival rate while onlays had the better periodontal outcomes [F3]; the survival rates of the different categories correspond to different mean follow-up periods and therefore cannot be ranked directly [F1]; and no statistically significant difference between materials was detected over short-term follow-up of 1 to 3 years, while the conclusion of that same review states that lithium disilicate restorations “may slightly outperform” resin-matrix ceramic restorations after 3 years, except for bulk fracture [F4]. The actual choice has to be assessed by a dentist from the intra-oral examination and the imaging.

Geographic scope: This is general health education based on international literature. It does not cover any particular country's insurance scheme or regulations; for how care and fees are organised, follow the rules where you are. Every source cited in this card is international peer-reviewed literature; no national legislation or insurance-benefit rule is cited.

TL;DR｜These Three Options Are Not in the Same Contest, So Their Survival Rates Cannot Be Ranked Directly

When a dentist says, “this tooth needs a prosthetic restoration”, you may hear three terms: all-ceramic crown (covering the entire tooth), veneer (a thin ceramic layer covering only the labial surface of an anterior tooth), and 3D-milled restoration (an inlay／onlay: a partial-coverage restoration made with digital design and a milling machine).

It is easy to find the survival rate for each online and then rank them intuitively. But that comparison is misleading, for reasons stated clearly in the literature.

A systematic review and meta-analysis of 46 articles, covering 1,715 participants and 4,209 restorations, calculated cumulative survival rates for four types of glass-ceramic restoration at the same time [F1]:

• Single crowns: 96%, mean follow-up 4.6 years, incidence of irreparable failure n=2.7 [F1]
• Partial-coverage restorations (including 3D-milled restorations): 90%, mean follow-up 6.2 years, incidence of irreparable failure n=5.9 [F1]
• Ceramic veneers: 90.2%, mean follow-up 6.5 years, incidence of irreparable failure n=8.2 [F1]
• Fixed dental bridges: 76.1%, mean follow-up 6.5 years, incidence of irreparable failure n=5.2 [F1]

Cautious interpretation (very important): note that these four figures have different follow-up periods—4.6 years for crowns, 6.2 years for partial coverage, and 6.5 years for veneers [F1]. A group with shorter follow-up will naturally have a better-looking figure. This is not a race with the same starting line, and these restorations are inherently used for different defect conditions; this was not a randomised head-to-head comparison.

The correct question is therefore not “which is strongest?” but: what remains of my tooth, and where is the missing area?

Build the Framework First: Three Questions Determine the Range of Options

Before discussing materials, first establish three points. They determine which options you have; only then does a material comparison become meaningful.

Question One: Is the Enamel Still Present?

This is the key to whether a veneer is feasible, and the evidence in the literature is fairly consistent.

A retrospective clinical study included 189 patients and 672 ceramic veneers followed for 1 to 15 years, dividing them into three groups according to the extent of dentine exposure after etching [F2]:

• GA1 (enamel only): survival rate 96.7% [F2]
• GA2 (dentine exposure < 30%): 95.3% [F2]
• GA3 (dentine exposure > 30%): 93.9% [F2]
• The difference between GA1 and GA3 was statistically significant (p = 0.033) [F2]
• The overall estimated cumulative survival at 15 years was 96%, with mean survival of 5.98 years [F2]

The same data also indicated that dentine exposure was associated with a higher risk of failure (odds ratio 3.47) and that root-canal-treated teeth also showed a higher risk of failure (odds ratio 1.68) [F2].

Cautious interpretation: there is a detail here that appears contradictory but must be presented honestly. The same study also recorded that root canal treatment, tooth-preparation design, and type of resin adhesive did not significantly affect survival (p > 0.05) [F2]. In other words, the signal that “root-canal-treated teeth have a higher risk” was present, but did not reach statistical significance in that study. What the study's conclusion identified as significantly affecting survival was the extent of dentine exposure [F2]. The statistical methods recorded in that abstract were Kaplan-Meier survival analysis, Log-Rank tests and odds ratios; no multivariable model is reported, so no factor can be described as having been confirmed or ruled out as an “independent” risk factor [F2].

It should also be added that all treatment was performed by the same dentist and all restorations were made by the same dental technician [F2]. This provides high internal consistency, but also means that the figures cannot be applied directly to every setting.

Question Two: How Extensive Is the Defect, and Does It Extend around the Cusps?

This determines whether partial coverage (a 3D-milled restoration) or full coverage (an all-ceramic crown) is considered.

A prospective, randomised within-arch clinical trial placed digitally manufactured lithium disilicate onlays and full crowns on opposite sides of the same patient's mouth for root-canal-treated posterior teeth in the mandibular arch (n = 15), with follow-up to 2 years [F3]:

• Full-crown survival was 100% and onlay survival 83.3%, a statistically significant difference (P = 0.030, 95% CI 0.01–0.12) [F3]
• But the onlays had significantly better periodontal outcomes: bleeding on probing (P = 0.000), plaque index (P = 0.001), and probing pocket depth (P = 0.000) were all lower at 1 and 2 years [F3]
• The onlays showed marginal discolouration in 20% and loss of marginal integrity in 13.3%, with a significant difference (P = 0.001)[F3]
• Neither group had fracture, secondary caries, or an evident change in surface texture, and patient satisfaction was 100% in both groups [F3]

Cautious interpretation: this study had n = 15 and only 2 years of follow-up [F3]. The sample was extremely small, so a single failure would cause a large swing in the percentage. It is useful for understanding the direction of the trade-offs: full coverage brought stability of the restoration itself at the cost of removing more tooth structure and having poorer periodontal measures; partial coverage preserved more tooth structure and was more favourable periodontally, but had more marginal problems [F3]. It is not suitable as proof that “full crowns are better”.

Question Three: How Long a Follow-up Horizon Can You Accept?

This concerns material selection, but the differences between materials are smaller and less stable than imagined.

Differences between Materials: More Uncertain than You May Think

Partial-Coverage Restorations: No Difference Is Apparent in the Short Term

A systematic review and meta-analysis that searched through February 2024 included 6 randomised controlled trials comparing posterior partial-coverage restorations made from different ceramic and ceramic-based materials (onlays, occlusal veneers, and partial crowns) [F4]:

• Resin-matrix ceramic (RMC) 3-year survival 89.3% (95% CI 76.4–95.3) [F4]
• Lithium disilicate (LDS) 3-year survival 93.7% (95% CI 83.7–97.7) [F4]
• Leucite-reinforced glass-ceramic (LRGC) ranged from 96.1% (95% CI 90.1–98.9) to 98.3% (95% CI 90.8–100) [F4]
• After 1 to 3 years of follow-up, LDS was slightly better than RMC for restoration failure and adhesive debonding: per 100 restoration-years, RMC had 1.56 more failures and 1.78 more adhesive debondings (low-certainty evidence) [F4]

Cautious interpretation: these two statements sit in different parts of the paper and must be read separately. The results section recorded that no statistically significant differences between ceramic and ceramic-based materials were detected during short-term follow-up of 1 to 3 years, and that the long-term performance of posterior partial-coverage restorations remains uncertain [F4]; the review's conclusion states that the survival of lithium disilicate restorations “may slightly outperform” resin-matrix ceramic restorations after 3 years of follow-up across outcomes, except for bulk fracture — the wording used is “may” [F4]. Note how wide the confidence intervals above are: RMC ranges from a lower bound of 76.4% to an upper bound of 95.3%, and the intervals overlap [F4]. Together with the “low-certainty evidence” label, these figures are insufficient to support a claim that “one material is clearly better”. The review also stated explicitly that ceramic and ceramic-based partial-coverage restorations are a reliable treatment option for restoring more extensive posterior defects [F4].

Extend the Horizon to 10 Years and Even the Direction Reverses

A systematic review and meta-analysis of 21 articles with at least 5 years of follow-up compared ceramic and resin inlays, onlays, and full-coverage restorations [F5]:

Estimated 5-year survival

• Resin 86% (n = 129)｜feldspathic porcelain 90% (n = 1,048)｜glass-ceramic 92% (n = 2,218)[F5]

Estimated 10-year survival

• Resin 75% (n = 115)｜feldspathic porcelain 91% (n = 1,829)｜glass-ceramic 89% (n = 1,075)[F5]

The review's pooled regression showed that ceramic partial-coverage restorations outperformed resin restorations at both 5 and 10 years. Between the two ceramic types, however, glass-ceramic outperformed feldspathic porcelain at 5 years, but by 10 years the direction reversed and feldspathic porcelain outperformed glass-ceramic [F5].

Cautious interpretation: note this reversal of direction. It may reflect a true difference in material behaviour, or it may reflect different sample compositions at the respective time points—for example, there were 2,218 glass-ceramic restorations at 5 years but only 1,075 at 10 years [F5]. Either way, the existing data provide no answer to “which ceramic is better?” that remains stable over time.

How Do These Restorations Fail When They Fail?

The conclusion of the same review recorded that failures were mostly due to fractures (6.2%), endodontic problems (3%), secondary caries (1.7%) and debonding (0.9%) [F5]. The abstract does not state the denominator for these percentages, and the four figures added together fall far short of 100%, so they are not a percentage breakdown of failure causes but the rates at which each type of problem was recorded within that review's dataset [F5].

This set of figures is still useful because it tells you what needs to be prevented: the source wording is that failures were “mostly due to” fractures, followed by problems inside the tooth [F5]. This also explains why “how much tooth structure remains” matters more than “which material is used”.

Bring the Framework Together: A Comparison Table

How to use this table: it helps you understand the context in which each option is discussed; it is not a table for self-diagnosis. Which options are feasible depends on an actual intraoral examination and interpretation of imaging.

What Does “Not Selling a Single Option” Actually Look Like?

Three honest observations can be drawn from the data above:

First, the more conservative the approach, the more tooth structure it preserves, but the more marginal problems it has. The onlays had better periodontal measures, but markedly higher proportions of marginal discolouration and loss of marginal integrity [F3].

Second, the more extensive the coverage, the more stable the restoration itself, but the cost is tooth structure and periodontal health. In the same trial, full-crown survival was 100%, but periodontal outcomes were poorer at both 1 and 2 years [F3].

Third, material differences are not statistically apparent in the short term, although the direction is not a complete blank. Six randomised controlled trials detected no significant differences between materials at 1 to 3 years and long-term performance was uncertain; the conclusion of that same review nonetheless states that lithium disilicate “may slightly outperform” resin-matrix ceramic, except for bulk fracture [F4].

In other words, the choice is not about selecting a “best product”, but balancing “how much tooth structure to preserve” against “how much stability to gain” under the conditions in your mouth. There is no universal answer to this balance because every tooth has something different left.

Conclusion｜Ask “What Remains?” before Asking “What Should Be Done?”

If you remember only one thing, remember this: these three approaches are not three grades; they are answers for three different extents of defects.

The literature can provide conditions and trade-offs: the more completely enamel is preserved, the better bonded restorations perform [F2]; conservative partial coverage is more favourable periodontally but has more marginal issues [F3]; short-term differences between materials did not reach statistical significance, although that review's conclusion still states that lithium disilicate “may slightly outperform” resin-matrix ceramic except for bulk fracture, and long-term data remain insufficient [F4][F5]; and survival rates for different categories cannot be ranked directly because their follow-up periods differ [F1].

Consider taking these questions to discuss with your dentist at the appointment:

1. How much tooth structure remains in this tooth? Is there enough enamel to support bonding?
2. Does the defect extend around the cusps? Is full coverage necessary?
3. If I choose a more conservative approach, what problem is most likely to occur?
4. Has this tooth had root canal treatment? Will that affect the options?

Changing the starting point of the choice from “which is better?” to “what remains?” will immediately make the discussion with your dentist much more concrete.

Risk factors (what to know before treatment)

• The most common form of failure is fracture: a systematic review and meta-analysis of 21 articles with follow-up longer than 5 years recorded that failures were mostly due to fractures (6.2%), endodontic problems (3%), secondary caries (1.7%) and debonding (0.9%); the abstract does not state the denominator for these percentages [F5]. This is why “how much tooth structure remains” matters more than “which material is used”.
• The cost of the conservative option shows up at the margin: in a cross-arch randomised trial on endodontically treated posterior teeth in the mandibular arch, onlays showed marginal discoloration (20%) and loss of marginal integrity (13.3%), with a statistically significant difference (P = 0.001) [F3]. That trial covered only 15 teeth and followed them to 2 years; the direction is informative, but the figures should not be treated as a personal expectation [F3].
• The cost of full coverage shows up in the periodontium: in the same trial, onlays performed significantly better on bleeding on probing, plaque index and probing pocket depth, and the authors recorded greater periodontal damage with full crowns at 1 and 2 years [F3].
• Conditions that reduce the survival of bonded restorations: in retrospective data on 672 veneers followed for 1 to 15 years, endodontically treated teeth and teeth with dentin exposure showed higher risks of failure (odds ratios of 1.68 and 3.47 respectively); the same paper also recorded that endodontic treatment, preparation design and resin cement type did not significantly affect survival (p > 0.05), and what that study identified as significant was the extent of dentin exposure [F2].
• The limits of the evidence itself: the review comparing materials included only 6 randomised controlled trials and states plainly that the long-term performance of posterior partial coverage restorations is uncertain [F4]; in the veneer study all treatment was carried out by a single clinician and all restorations were made by a single ceramist, which gives high internal consistency but limits generalisability [F2]. This card did not run a separate literature search on contraindications and therefore does not compile a list of them; which approach is feasible, and whether pulpal or periodontal conditions need to be addressed first, has to be assessed by a dentist from the intra-oral examination and the imaging.

*This article is a review of the literature, not personalised medical advice. The cited studies differ in sample size, follow-up period, and applicable populations; discuss your individual circumstances with your dentist.*

Every clinical statement in this article is mapped line by line to its cited source (see the sources and evidence chain below). It has not been clinically reviewed by a licensed practitioner. This is health information, not individual advice; assessment by a clinician is required.