Solicitors instructing a dental expert for the first time often ask the same question early on: should this be a single joint expert, or an expert instructed for one side only? The answer depends on the track the claim is on, the issues in dispute, and sometimes on tactics. The underlying duty to the court is the same either way, but the practical experience of instructing differs.
What a single joint expert is
A single joint expert (SJE) is appointed jointly by claimant and defendant, usually under CPR 35.7, with both parties able to give instructions and both bound by the same report. SJE appointment is common on the small claims and fast track, and increasingly requested on multi-track cases where the dental issues are discrete and not the central battleground of the litigation, for example a condition and prognosis report following a road traffic accident where causation is not seriously contested.
Acting as an SJE means taking instructions from both sides, addressing questions from both sides, and producing a single report that does not favour either party. Where the parties cannot agree on joint instructions, the court can give directions, but in practice most SJE work proceeds by both solicitors agreeing a letter of instruction or each sending their own questions to be addressed in the same report.
What a party expert is
A party expert is instructed by one side only, claimant or defendant, and reports to that party in the first instance under privilege. Even though the report is commissioned by one party, the expert's overriding duty under CPR 35.3 is to the court, not to whoever is paying the fee. A properly written party expert report should reach the same opinion regardless of which side instructed it.
Party experts are more usual in clinical negligence claims where breach of duty and causation are genuinely contested, since each side typically wants the opportunity to take its own expert's view before deciding whether to disclose it. Personal injury claims with a disputed mechanism of injury, or cases proceeding to a contested trial, are also more likely to involve experts instructed separately by each party.
Why the distinction matters practically
The duty not to take sides is identical whichever route is used. What differs is the instruction process itself. SJE work usually moves faster, since there is one report and one set of CPR 35 questions to manage rather than two reports to compare and reconcile. Party expert work allows each side to consider their own expert's opinion before deciding on disclosure, but typically leads to a joint statement and discussion between experts once both reports are exchanged, which adds a stage to the timetable.
Neither route changes how a report should be written. I approach an SJE instruction and a party instruction the same way: setting out the facts, distinguishing assumption from opinion, and reaching the conclusion the evidence supports. The difference is procedural, not substantive. Once a report is produced, either route can lead to Part 35 questions, and party expert instructions typically proceed to a joint statement once both reports are exchanged.
Which route to choose
For straightforward condition and prognosis work, or cases on the fast track, an SJE is usually the more proportionate and cost-effective route, and is often directed by the court in any event. For contested breach of duty and causation cases on the multi-track, party experts followed by a joint statement remain the norm. Where there is doubt, this is worth raising at the case management stage rather than after instructions have already gone out.